MEMCAL 


VON  WBRTHERN 


THE  MEDICAL  STUDENT'S 


OF  CHEMISTRY 


BY 

R.   A.   WITTHAUS,   A.M.,  M.D. 

Profess*  of  Chemistry,  Physics  and  Toxicology  in  Cornell  University  Medical  College  in  New  York 
vCity ;  Member  of  the  Chemical  Societies  of  Paris  and  Berlin;  Member  of  the  American 
%^X.      Chemical  Society;  Fellow  of  the  New  York  Academy  of  Medicine;  of  the 


SSI 


American  Association  for  the  Advancement  of  Science;  of  the 
Medical  Society  of  the  State  of  New  York,  etc. 


ffiftb  EMtion 


NEW    YORK 
WILLIAM    WOOD    &    COMPANY 

MDCCCCII 

'  . 


COPYRIGHT,  1902, 
BY  WILLIAM    WOOD    &    COMPANY 


- 


illrnnnnt    JTir«n 
J.  Horace  McFarland  Company 
Harrisburg,  Pennsylvania 


PREFACE   TO   THE  PRESENT  EDITION. 

IN  the  edition  herewith  presented  the  section  on  chemical  physics 
has  been  somewhat  extended  to  include  brief  consideration  of  those 
results  of  physical  investigation  which  have  become  most  important 
supports  of  the  principles  deduced  from  observations  of  chemical 
phenomena. 

The  section  on  mineral  chemistry  has  been  condensed  to  the  mini- 
mum, and  in  it  the  study  of  the  philosophy  of  chemistry  and  of  the 
broad  principles  of  the  science  have  been  considered,  rather  than  the 
details  of  isolated  facts  or  the  descriptions  of  technical  processes. 

The  section  on  organic  chemistry  has  been  rearranged,  in  great 
part  rewritten,  and  somewhat  extended.  The  prominence  given  to 
this  branch  of  the  subject  the  author  believes  to  be  justified,  not- 
withstanding its  intricacy  and  the  apparent  difficulty  of  teaching  it 
satisfactorily  to  medical  students,  because  of  the  intimate  connection 
of  organic  chemistry  with  physiology  and  with  modern  pharmacy,  and 
the  impossibility  of  comprehension  of  the  problems  of  animal  and 
pharmaceutical  chemistry  without  the  possession  of  an  adequate 
knowledge  of  the  principles  of  organic  chemistry. 

The  references  to  subjects  within  the  scope  of  physiological  chem- 
istry which  were  scattered  throughout  the  book  in  previous  editions 
have  been  omitted,  and  the  subject  has  been  treated  of  more  in 
extenso,  in  its  more  important  branches,  in  a  section  by  itself,  as  the 
importance  of  this  application  of  chemistry  in  the  medical  curriculum 
undoubtedly  demands.  This  section  is  devoted  to  the  consideration 
of  the  composition  of  the  more  important  fluids  of  the  body,  and  of 
physiological  chemical  processes;  the  description  of  the  properties 
and  chemical  relationships  of  substances  of  physiological  interest, 
which  is  within  the  domain  of  pure  chemistry,  being  contained  in  the 
previous  sections  on  mineral  and  organic  chemistry. 

The  section  on  laboratory  technics,  contained  in  previous  editions, 
has  been  omitted  from  this  one,  as  the  subjects  therein  considered 
are  best  treated  of  in  a  laboratory  handbook,  which  this  is  not. 

The  arrangement  of  the  subjects  herein  considered  is  that  directed 


iv  PREFACE    TO    THE    PRESENT    EDITION 

by  their  logical  sequence,  but  the  instructor  will  probably  find  it 
desirable  to  depart  from  it  somewhat  in  use.  Thus  it  is  suggested 
that  the  beginner  be  taught  the  properties  of  a  few  of  the  acidulous 
and  basic  elements,  acids  and  bases,  before  being  led  to  the  consider- 
ation of  general  principles  treated  of  in  the  first  section. 

R.  A.  W. 

NEW  YORK,  May  1,  1902. 


PREFACE  TO  THE  FIRST  EDITION. 

IN  venturing  to  add  another  to  the  already  long  list  of  chemical 
text -books,  the  author  trusts  that  he  may  find  some  apology  in  this, 
that  the  work  is  intended  solely  for  the  use  of  a  class  of  students 
whose  needs  in  the  study  of  this  science  are  peculiar. 

While  the  main  foundations  of  chemical  science — the  philosophy 
of  chemistry — must  be  taught  to  and  studied  by  all  classes  of  stu- 
dents alike,  the  subsequent  development  of  the  study  in  its  details 
must  be  moulded  to  suit  the  purposes  to  which  the  student  will  sub- 
sequently put  his  knowledge.  And  particularly  in  the  case  of  medi- 
cal students,  in  our  present  defective  methods  of  medical  teaching, 
should  the  subject  be  confined  as  closely  as  may  be  to  the  general 
truths  of  chemistry  and  its  applications  to  medical  science. 

In  the  preparation  of  this  Manual  the  author  has  striven  to  pro- 
duce a  work  which  should  contain  as  much  as  possible  of  those  por- 
tions of  special  chemistry  which  are  of  direct  interest  to  the  medical 
practitioner,  and  at  the  same  time  to  exclude,  so  far  as  possible, 
without  detriment  to  a  proper  understanding  of  the  subject,  those 
portions  which  are  of  purely  technological  interest.  The  descrip- 
tions of  processes  of  manufacture  are,  therefore,  made  very  brief, 
while  chemical  physiology  and  the  chemistry  of  hygiene,  therapeutics 
and  toxicology  have  been  dwelt  upon. 

The  work  has  been  divided  into  three  parts.  In  the  first  part  the 
principles  of  chemical  science  are  treated  of,  as  well  as  so  much  of 
chemical  physics  as  is  absolutely  requisite  to  a  proper  understanding 
of  that  which  follows.  A  more  extended  study  of  physics  is  pur- 
posely avoided,  that  subject  being,  in  the  opinion  of  the  author, 
rather  within  the  domain  of  physiology  than  of  chemistry. 

The  second  part  treats  of  special  chemistry,  and  in  this  certain 
departures  from  the  methods  usually  followed  in  chemical  text-books 
are  to  be  noted.  The  elements  are  classed,  not  in  metals  and  metal- 
loids—a classification  as  arbitrary  as  unscientific  — but  into  classes 
and  groups  according  to  their  chemical  characters. 

In  the  text  the  formula  of  a  substance  is  used  in  most  instances 

(v) 


vi  PREFACE    TO    THE    FIRST    EDITION 

in  place  of  its  name,  after  it  has  been  described,  with  a  view  to  giving 
the  student  that  familiarity  with  the  notation  which  can  only  be 
obtained  by  continued  use. 

In  the  third  part  those  operations  and  manipulations  which  will 
be  of  utility  to  the  student  and  physician  are  briefly  described,  not 
with  the  expectation  that  these  directions  can  take  the  place  of  actual 
experience  in  the  laboratory,  but  merely  as  an  outline  sketch  in  aid 
thereto. 

Although  the  Manual  puts  forth  no  claim  as  a  work  upon  ana- 
lytical chemistry,  we  have  endeavored  to  bring  that  branch  of  the 
subject  rather  into  the  foreground  so  far  as  it  is  applicable  to  medical 
chemistry.  The  qualitative  characters  of  each  element  are  given 
under  the  appropriate  heading,  and  in  the  third  part  a  systematic 
scheme  for  the  examination  of  urinary  calculi  is  given.  Quantitative 
methods  of  interest  to  the  physician  are  also  described  in  their  appro- 
priate places.  In  this  connection  the  author  would  not  be  understood 
as  saying  that  the  methods  recommended  are  in  all  instances  the  best 
known,  but  simply  that  they  are  the  best  adapted  to  the  limited 
facilities  of  the  physician. 

The  author  would  have  preferred  to  omit  all  mention  of  Troy  and 
Apothecaries'  weight,  but  in  deference  to  the  opinions  of  those  ven- 
erable practitioners  who  have  survived  their  student  days  by  half  a 
century,  those  weights  have  been  introduced  in  brackets  after  the 
Metric,  as  the  value  of  degrees  Fahrenheit  have  been  made  to 

follow  those  Centigrade. 

R.  A.  W. 

BUFFALO,  N.  Y.,  September  16,  1883. 


TABLE   OP   CONTENTS. 

PAGE 

INTRODUCTION     . 1 

Properties  of  Matter: 

Indestructibility — Impenetrability — Weight— Specific  Gravity — Divis- 
ibility—  States  of  Matter  —  Crystallization  —  Allotropy     .    .      1-13 

Physical  Actions  of  Chemical  Interest 13 

Heat: 

Change  of  State  — Temperature  — Thermometers  —  Fusion  —  Latent 
Heat  —  Solution  —  Solidification  —  Law  of  Eaoult  —  Vapori- 
zation —  Boiling  —  Liquefaction  —  Sublimation  —  Gases  and 

Vapors  — Thermal  Unit -Specific  Heat 13-19 

Osmose  —  Diffusion  —  Dialysis 20 

Light : 
Index  of  Refraction — Spectroscopy — Polarimetry— Chemical  Effects 

of  Light .       .       21-26 

Electricity : 

Galvanic  Electricity  —  Electrical  Units  —  Electrolysis  —  Electro- 
chemical Series  —  lonization 26-30 

Chemical  Combination: 

Elements  —  Compounds  —  Laws  of  Combination  —  Atoms — Mole- 
cules—  Atomic  Theory  —  Atomic  and  Molecular  Weight  — 
Valence  —  Symbols  —  Formulae  —  Equations  —  Acids,  Bases 
and  Salts  —  Electrolytic  Dissociation  —  Actions  of  acids,  bases 
and  salts  upon  each  other  —  Stoichiometry  —  Nomenclature  — 
Radicals  —  Composition  and  Constitution  —  Classification  of 
Elements 30-58 

INORGANIC   CHEMISTRY 59 

TYPICAL  ELEMENTS 59 

Hydrogen 59 

Helium 62 

Oxygen 63 

Compounds  of  Hydrogen  and  Oxygen: 
Water  — Natural  Waters  — Hydrogen  Peroxid 67-78 

ACIDULOUS  ELEMENTS 

Chlorin  Group 

Fluorin 

Chlorin    .    .    . •    •    •   • 

Compounds  of  Chlorin: 

Hydrogen    Chlorid  —  Chlorids  —  Oxids    of    Chlorin  —  Acids    of 

Chlorin 

Bromin 

Compounds  of  Bromin: 

Hydrogen  Bromid  —  Bromids  — Oxacids  of  Bromin 

(vii) 


viii  TABLE   OF    CONTENTS 

PAGE 

lodin 88 

Compounds  of  lodin: 

Hydrogen  lodid  — lodids  — Chlorids  — Oxacids 89-90 

Sulfur  Group 91 

Sulfur 91 

Compounds  of  Sulfur: 

Hydrogen  Sulfids  —  Sulfids  and  Hydrosulfids  —  Sulfur  Haloids  — 
Sulfur  Dioxid— Sulfur  Trioxid— Oxacids  of  Sulfur— Sulfites  — 

Sulfates 92-100 

Selenium  and  Tellurium 100 

Nitrogen  Group 101 

Nitrogen 101 

Atmospheric  Air 102 

Compounds  of  Nitrogen: 

Ammonia — Hydrazin— Hydrazoic  Acid  —  Hydroxylamin  —  Nitro- 
gen Haloids — Oxids  of  Nitrogen  —  Hyponitrous  Acid  —  Nitrous 

Acid— Nitrites  — Nitric  Acid  — Nitrates 102-104 

Phosphorus 112 

Compounds  of  Phosphorus: 

Hydrogen  Phosphids-  Phosphorus  Haloids  —  Oxids  of  Phos- 
phorus—  Phosphorus  Acids  —  Phosphates 118-122 

Arsenic 122 

Compounds  of  Arsenic: 

Hydrogen  Arsenids  —  Arsenic  Haloids  —  Oxids  of  Arsenic — 
Arsenic  Acids  —  Arsenic  Sulfids — Toxicology  of  Arsenic  Com- 
pounds    123-135 

Antimony 136 

Compounds  of  Antimony: 
Hydrogen  Antimonid — Antimony  Haloids — Oxids  of  Antimony — 

Antimony  Acids  —  Sulfids  of  Antimony 136-139 

Boron  Group      140 

Boron 140 

Compounds  of  Boron 140 

Carbon  Group 141 

Carbon 141 

Silicon 143 

Vanadium  Group 145 

Vanadium — Niobium — Tantalum 145 

Molybdenum  Group 145 

Molybdenum— Tungsten— Osmium      145 

AMPHOTERIO  ELEMENTS 146 

Gold  Group 146 

Gold      146 

Iron  Group 147 

Chromium 147 

Compounds  and  Salts  of  Chromium 147-148 

Manganese      148 

Compounds  and  Salts  of  Manganese 149-150 

Iron  150 

Compounds  and  Salts  of  Iron 151-156 


TABLE    OF    CONTENTS  ix 

PAQB 

Uranium  Group 156 

Uranium l^g 

Lead  Group 157 

Lead : 157 

Compounds  and  Salts  of  Lead 158-161 

Bismuth  Group 162 

Bismuth 162 

Compounds  and  Salts  of  Bismuth ...  162-164 

Tin  Group 164 

Titanium,  Zirconium 164 

Tin 165 

Compounds  and  Salts  of  Tin 165-166 

Platinum  Group— Rhodium  Group 166 

Platinum 167 

BASYLOUS  ELEMENTS 168 

Sodium  Group 168 

Lithium 168 

Sodium 169 

Compounds  and  Salts  of  Sodium 169-174 

Potassium 175 

Compounds  and  Salts  of  Potassium 175-183 

Silver 183 

Compounds  and  Salts  of  Silver 183-185 

Ammonium  Compounds  and  Salts 185-187 

Thallium  Group 188 

Thallium 188 

Calcium  Group     188 

Calcium 188 

Compounds  and  Salts  of  Calcium 188-191 

Strontium 391 

Barium 192 

Magnesium  Group 193 

Magnesium 193 

Compounds  and  Salts  of  Magnesium 194-195 

Zinc 195 

Compounds  and  Salts  of  Zinc 196-198 

Cadmium 198 

Aluminium  Group 198 

Aluminium 198 

Compounds  and  Salts  of  Aluminium 199-201 

Beryllium,  Scandium,  Gallium,  Indium •    202 

Nickel  Group 203 

Nickel— Cobalt 

Copper  Group 

Copper 204 

Compounds  and  Salts  of  Copper 204-208 

Mercury 

Compounds  and  Salts  of  Mercury 208-215 


X  TABLE    OF    CONTENTS 

PAGE 

ORGANIC  CHEMISTRY 216 

COMPOUNDS  OP  CARBON: 

Radicals — Homologous  Series  —  Isomerism  —  Elementary  Organic 
Analysis  —  Determination  of  Molecular  Weights  —  Determina- 
tion of  Constitution  —  Nomenclature  —  Classification.  .  .216-2128 

OPEN-CHAIN,  ALIPHATIC,  ACYCLIC,  OK  FATTY  -COMPOUNDS 229-377 

Hydrocarbons 229 

Saturated  Compound— Methane  Series 229-308 

Hydrocarbons      229-232 

Haloid  Derivatives 233-237 

Oxidation  products  of  the  Paraffins 237-311 

Alcohols 239-255 

Aldehydes 255-261 

Ketones,  or  Acetones 261-262 

Aldehyde  -  alcohols  —  Ketone  -  alcohols — Aldehyde  -  ketones  —  and 

Oxyaldebyde-ketones 262  277 

Carbohydrates 263  277 

Carboxylic  Acids  : 

Paraffin  moncarboxylic  acids — Paraffin  dicarboxylic  acids — Par- 
affin poiycarboxylic  acids  —  Oxyacids  —  Aldehyde  -  acids  — 

Ketone-acids 277-299 

Simple  Ethers 299-302 

Anhydrids— Oxids  of  Carbon — Acidyl  Anhydrids 302-311 

Acidyl  Haloids 311 

Esters,  Compound  Ethers  —  Alkyl  esters  —  Esters  of  the  Glycols— 
Glycerol  esters  —  Esters  of  polyhydric  alcohols  —  Lactids  and 

Lactones 311-331 

Sulfur  Derivatives  of   the  Paraffins .    .321-324 

Organo-metallic  Compounds 324 

Nitrogen  derivatives  of  the  Paraffins  : 

Nitro- paraffins  —  Monamins  —  Oxyamins,  Hydramins  —  Diamins — 
Imins — Diimins — Amidins  — Amidoxims  — Hydroxamic  Acids — 
Guanidins — Hydrazins — Nitrils — Azoparaffins,  Cyanogen  Com- 
pounds— Amids — Amic  Acids — Imids — Compound  Ureas — Uric 
Acid  and  Xanthin  Bases  —  Nitrogen  Derivatives  of  Alcohols — 
Aldehydes  and  Ketones — Nitro-acids — Amido-acids — Lactams. 

324-367 

Phosphorus,  Antimony  and  Arsenic  Derivatives      367-368 

Unsaturated  Aliphatic  Compounds 368  377 

Hydrocarbons  : 

Ethene,  Ethine,  Diolefin,  and  superior  Series  —  Halogen  De- 
rivatives    368-371 

Unsaturated  Oxidation  Products: 

Alcohols— Aldehydes— Acids— Oxids 371-376 

Sulfur  and  Nitrogen  Derivatives 376-377 

CLOSED-CHAIN  COMPOUNDS — CYCLIC  COMPOUNDS 378-496 

Hexacarbocylic  Compounds— Aromatic  Substances 380-451 

Monobenzenic  Compounds 385-431 

Hydrocarbons 385-387 


TABLE    OF   CONTENTS  xi 

PAGE 

Haloid  derivatives 387 

Benzenic  Oxygen  Compounds  : 

Phenols — Quinones — Aromatic  Alcohols — Alphenols — Aldehydes — 
Ketones  —  Acids  —  Alcohol- Acids— Aldehyde- Acids  —  Ketone- 
Acids — Esters — Glucosids — Anhydrids — Acid  haloids  ....  388-415 

Aromatic  Sulfur  Derivatives — Sulfonic  Acids  , 415-416 

Nitrogen -containing  Derivatives  of  Benzene  : 

Nitro  and  Nitroso  Compounds— Hydroxylamin  Compounds — Amido 
Compounds — Diazo-,  Diazoamido-,  and  Azo  Compounds — Hy- 

radzin  Compounds  416-431 

Heteroaromatic  Compounds,  with  e.  single  Nucleus 431-438 

Hydrocarbons 431-434 

Alcohols  434-436 

Ketones— Acids      ...  436-438 

Compounds  with  Condensed  Nuclei 438-446 

Hydrocarbons 438-441 

Haloid  Derivatives— Orientation 441-442 

Phenols — Alcohols — Aldehydes  —  Ketones  —  Quinones — Carboxylic 

Acids 442-445 

Nitrogen  Derivatives    .    .  445-446 

Diphenyl  and  its  Derivatives 446-447 

Diphenyl-paraffins — Diphenyl-olefins—  Diphenyl -actylenes  and  their 

Derivatives 447-451 

Heterocyclic  Compounds 452-496 

Mononucleate  Heterocyclic  Compounds         454-460 

Five-membered  rings 454-458 

Six-membered  rings 458-460 

Condensed  Heterocyclic  Compounds 460-468 

Phenyl-pyridyl  —  Dipyridyl  — and    Pyridyl- pyrrole    Compounds  — 

Alkaloids— Ptomains— Toxins    .  469-496 

SUBSTANCES  OF  UNKNOWN  CONSTITUTION — PROTEINS 497-509 

PHYSIOLOGICAL  CHEMISTRY 510-627 

Digestion      •  512-538 

Saliva 

Gastric  Secretion  and  Digestion 

Bile  

Pancreatic  Secretion    ....  533-5 

Intestinal  Secretions 

Chemical  Changes  in  the  Intestine 

Blood 538-566 

Urine S66'6-1 

Milk 621-627 

APPENDIX 629-641 

INDEX  .  643-678 


THE  MEDICAL  STUDENT'S 

MANUAL  OF  CHEMISTRY. 


INTRODUCTION. 

THE  simplest  definition  of  chemistry  is  a  modification  of  that 
given  by  Webster :  That  branch  of  science  which  treats  of  the 
composition  of  substances,  their  changes  in  composition,  and  the 
laws  governing  such  changes. 

If  a  bar  of  soft  iron  be  heated  sufficiently  it  becomes  luminous  ; 
if  caused  to  vibrate  it  emits  sound  ;  if  introduced  within  a  coil  of 
wire  through  which  a  galvanic  current  is  passing,  it  becomes  mag- 
netic and  attracts  other  iron  brought  near  it.  Under  all  these 
circumstances  the  iron  is  still  iron,  and  so  soon  as  the  heat,  vibra- 
tion, or  galvanic  current  ceases,  it  will  be  found  with  its  original 
characters  unchanged  ;  it  has  suffered  no  change  in  composition. 
If  now  the  iron  be  heated  in  an  atmosphere  of  oxygen  gas,  it  burns, 
and  is  converted  into  a  substance  which,  although  it  contains  iron, 
has  neither  the  appearance  nor  the  properties  of  that  metal.  The 
iron  and  a  part  of  the  oxygen  have  disappeared,  and  have  been 
converted  into  a  new  substance,  differing  from  either  ;  there  has 
been  change  in  composition,  there  has  been  chemical  action. 
Changes  wrought  in  matter  by  physical  forces,  such  as  light,  heat, 
and  electricity,  are  temporary,  and  last  only  so  long  as  the  force  is 
active  ;  except  in  the  case  of  changes  in  the  state  of  aggregation,  as 
when  a  substance  is  pulverized  or  fashioned  into  given  shape. 
Changes  in  chemical  composition  are  permanent,  lasting  until  some 
other  change  is  brought  about  by  another  manifestation  of  chemical 
action. 

However  distinct  chemical  may  thus  be  from  physical  forces,  it 
is  none  the  less  united  with  them  in  that  grand  correlation  whose 
existence  was  first  announced  by  Grove,  in  1842.  As,  from  chem- 
ical action,  manifestations  of  every  variety  of  physical  force  may  !>«• 
obtained  :  light,  heat,  and  mechanical  force  from  the  oxidation  of 
carbon  ;  and  electrical  force  from  the  action  of  zinc  upon  sulfuric 

A  (1) 


2  MANUAL    OF    CHEMISTRY 

acid  —  so  does  chemical  action  have  its  origin,  in  many  instances, 
in  the  physical  forces.  Luminous  rays  bring  about  the  chemical 
decomposition  of  the  salts  of  silver,  and  the  chemical  union  of 
chlorin  and  hydrogen;  by  electrical  action  a  decomposition  of  many 
compounds  into  their  constituents  is  instituted,  while  instances  are 
abundant  of  reactions,  combinations,  and  decompositions  which  re- 
quire a  certain  elevation  of  temperature  for  their  production.  While, 
therefore,  chemistry  in  the  strictest  sense  of  the  term,  deals  only 
with  those  actions  which  are  attended  by  a  change  of  composition  in 
the  material  acted  upon,  yet  chemical  actions  are  so  frequently,  nay 
universally,  affected  by  existing  physical  conditions,  that  the  chemist 
is  obliged  to  give  his  attention  to  the  science  of  physics,  in  so  far, 
at  least,  as  it  has  a  bearing  upon  chemical  reactions,  to  chemical 
physics  —  a  branch  of  the  subject  which  has  afforded  very  important 
evidence  in  support  of  theoretical  views  originating  from  purely 
chemical  reactions. 

PROPERTIES    OF    MATTER. 

Indestructibility. — The  result  of  chemical  action  is  change  in  the 
composition  of  the  substance  acted  upon,  a  change  accompanied  by 
corresponding  alterations  in  its  properties.  Although  we  may  cause 
matter  to  assume  a  variety  of  different  forms,  and  render  it,  for  the 
time  being,  invisible,  yet  in  none  of  these  changes  is  there  the 
smallest  particle  of  matter  destroyed.  When  carbon  is  burned  in 
an  atmosphere  of  oxygen,  it  disappears,  and,  so  far  as  we  can  learn 
by  the  senses  of  sight  or  touch,  is  lost;  but  the  result  of  the  burning 
is  an  invisible  gas,  whose  weight  is  equal  to  that  of  the  carbon  which 
has  disappeared, "plus  the  weight  of  the  oxygen  required  to  burn  it. 

Impenetrability. — Although  one  mass  of  matter  may  penetrate 
another,  as  when  a  nail  is  driven  into  wood,  or  when  salt  is  dis- 
solved in  water,  the  ultimate  particles  of  which  matter  is  composed 
cannot  penetrate  each  other,  and,  in  cases  like  those  above  cited,  the 
particles  of  the  softer  substance  are  forced  aside,  or  the  particles  of 
one  substance  occupy  spaces  between  the  particles  of  the  other. 
Such  spaces  exist  between  the  ultimate  particles  of  even  the  densest 
substances. 

Weight. — All  bodies  attract  each  other  with  a  force  which  is  in 
direct  proportion  to  the  amount  of  matter  which  they  contain.  The 
force  of  this  attraction,  exerted  upon  surrounding  bodies  by  the 
earth,  becomes  sensible  as  weight,  when  the  motion  of  the  attracted 
body  toward  the  center  of  gravity  of  the  earth  is  prevented. 

In  chemical  operations  we  have  to  deal  with  three  kinds  of  weight: 
absolute,  apparent  and  specific. 


WEIGHT  3 

The  Absolute  Weight  of  a  body  is  its  weight  in  vacuo.  It  is 
determined  by  placing  the  entire  weighing  apparatus  under  the 
receiver  of  an  air-pump. 

The  Apparent  Weight,  or  Relative  Weight,  of  a  body  is  that 
which  we  usually  determine  with  our  balances,  and  is,  if  the  volume 
of  the  body  weighed  be  greater  than  that  of  the  counter -poising 
weights,  less  than  its  true  weight.  Every  substance  in  a  liquid  or 
gaseous  medium  suffers  a  loss  of  apparent  weight  equal  to  that  of 
the  volume  of  the  medium  so  displaced.  For  this  reason  the  appar- 
ent weight  of  some  substances  may  be  a  minus  quantity.  Thus,  if 
the  air  contained  in  a  vessel  suspended  from  one  arm  of  a  poised 
balance  be  replaced  by  hydrogen,  that  arm  of  the  balance  to  which 
the  vessel  is  attached  will  rise,  indicating  a  diminution  in  weight. 

In  stating  quantities  of  any  kind  the  expression  must  be  made  in 
terms  of  some  accepted  unit.  For  all  measures  of  extension  and 
weight  the  unit  accepted  in  all  scientific  literature  is  the  metre. 

The  metre  is  approximately  the  10,000,000th  of  the  quadrant  of 
the  earth's  meridian,  measured  from  the  pole  to  the  equator.  It  is 
the  distance  between  two  points  upon  a  bar  of  platinum  preserved  in 
the  mint  at  Paris.  It  is  equal  to  39.37079  inches. 

The  metre  is  subdivided  decimally,  and  its  fractions  are  designated 
by  the  Latin  numerals.  The  metre  contains  10  decimetres,  100 
centimetres,  and  1000  millimetres  (as  the  dollar  contains  10  dimes, 
100  cents,  and  1000  mills).  The  multiples  of  the  metre  are  desig- 
nated by  the  Greek  numerals :  10  metres=l  decametre,  100  metres 
=1  hectometre,  and  1000  metres^l  kilometre. 

The  measures  of  surface  and  of  volume  are  expressed  in  terms  of 
the  squares  and  the  cubes  of  the  measures  of  length.  The  cubic 
decimetre  is  the  unit  used  in  measuring  liquids  and  gases,  and  is 
called  the  litre.  The  litre  contains  1000  cubic  centimetres  (cc.).  It 
is  equal  to  1.0567  American  quarts,  or  0.8802  English  quart. 

The  gram,  the  unit  of  weight,  is  a  derivative  of  the  metre.  It  is 
the  absolute  weight  of  a  cubic  centimetre  of  distilled  water,  taken  at 
4°C.  (=39.2°  Fahr. ,  the  temperature  of  greatest  density  of  water) .  The 
decimal  fractions  and  multiples  of  the  gram  are  designated  in  the  same 
manner  as  are  those  of  the  metre.  (See  Table  II,  in  the  appendix.) 

The  Specific  Weight,  or  Specific  Gravity,  of  a  substance  is  the 
weight  of  a  given  volume  of  that  substance,  as  compared  with  the 
weight  of  an  equal  bulk  of  some  substance,  accepted  as  a  standard 
of  comparison,  under  like  conditions  of  temperature  and  pressure. 
The  sp.  gr.  of  solids  and  liquids  are  referred  to  water;  those  of 
gases  to  air  or  to  hydrogen.*  As,  by  reason  of  their  different  rates 


the  sp.  gr.  of  pure  air  (hydrogen=l)  is  14.42,  the  sp.  gr.  in  terms  of  air  X  14.42-sp.jr  i 
hydrogen.    Thus,  the  sp.  gr.  of  hydrochloric  acid  gas  (A=l)  is  1.2o9.    Its  sp.  gr.  ( 


*As 

terms  of 
therefore  1.259  X  14.42=18.155. 


4  MANUAL    OF    CHEMISTRY 

of  expansion  by  heat,  solids  and  liquids  do  not  have  the  same  sp.  gr. 
at  all  temperatures,  that  at  which  the  observation  is  made  should 
always  be  noted,  or  some  standard  temperature  adopted.  The 
standard  temperature  adopted  by  some  continental  writers  and  in  the 
U.  S.  P.  is  15°  (59°  F.).  Other  standard  temperatures  are  4°  (39.2° 
F.),  used  by  most  continental  writers,  and  15.6°  (60°  F.),  used  in 
Great  Britain  and  to  some  extent  in  this  country. 

In  expressing  the  sp.  gr.  of  heavy  liquids  the  weight  of  1  volume 
of  water  is  taken  as  unity.  Thus  the  sp.  gr.  of  sulfuric  acid  being 
1.84,  if  1  cc.  of  water  weighs  1  gram  1  cc.  of  sulfuric  acid  weighs 
1.84  grams.  For  the  sp.  gr.  of  light  liquids  1000  volumes  of  water 
are  sometimes  taken  as  unity  (to  avoid  cumbrous  fractions).  Thus 
the  specific  gravity  of  a  urine  being  1026,  1000  cc.  of  the  urine  will 
weigh  1026  grams,  or  1.026  kilos. 

The  relative  density  (or,  usually,  simply  density)  of  a  substance 
is  the  weight  of  its  unit  of  volume.  In  metric  the  specific  gravity 
and  density  are  the  same:  1  litre  of  water  weighs  1  kilo.  (sp.  gr.= 
1000),  and  1  cc.  weighs  1  gram  (sp.  gr.=  1.00).  The  density  of 
water  in  terms  of  the  weight  of  a  cubic  foot  is  62.42  avdp.  Ibs.,  or 
75.83  Troy  Ibs.  The  word  "density"  is  sometimes  used  arbitrarily 
to  apply  to  specific  gravity  in  the  aeriform  state 
as  referred  to  hydrogen. 

To  determine  the  sp.  gr.  of  substances,  different 
methods  are  adopted,  according  as  the  substance 
is  in  the  solid,  liquid,  or  gaseous  state;  is  in  mass 
or  in  powder;  or  is  soluble  or  insoluble  in  water. 

SOLIDS. — The  substance  is  heavier  than  water, 
insoluble  in  that  liquid,  and  not  in  powder. — It  is 
attached  by  a  fine  silk  fibre  or  platinum  wire  to  a 
hook   arranged   on  one  arm  of   the  balance,  and 
weighed.     A  beaker  full  of  pure  water  is  then  so 
placed  that  the  body  is  immersed  in  it  (Fig.  1), 
and  a  second   weighing   made.     By  dividing   the 
weight  in   air   by  the   loss   in  water,  the  sp.   gr.  (water  =  1.00)   is 
obtained.     Example: 

A  piece  of  lead  weighs  in  air 82.0 

A  piece  of  lead  weighs  in  water 74.9 

Loss  in  water 7.1 

82.0 

-—  =  11.55  =  sp.  gr.  of  lead 

The  substance  is  in  powder,  insoluble  in  water. — The  specific  grav- 
ity bottle  (Fig.  3),  filled  with  water,  and  the  powder,  previously 


SPECIFIC    GRAVITY  5 

weighed  and  in  a  separate  vessel,  are  weighed  together.  The  water 
is  poured  out  of  the  bottle,  into  which  the  powder  is  introduced,  with 
enough  water  to  fill  the  bottle  completely.  The  weight  of  the  bottle 
and  its  contents  is  now  determined.  The  weight  of  the  powder  alone, 
divided  by  the  loss  between  the  first  and  second  weighings,  is  the 
specific  gravity.  Example: 

Weight  of  iron  filings  used 6.562 

Weight  of  iron  filings  and  sp.  gr.  bottle  filled  with  water 148.327 

Weight  of  sp.  gr.  bottle  containing  iron  filings  and  filled  with  water  .    .    147.470 


Water  displaced  by  iron 0.857 


0.857 


The  substance  is  lighter  than  water. — A  sufficient  bulk  of  some 
heavy  substance,  whose  sp.  gr.  is  known,  is  attached  to  it  and  the 
same  method  followed,  the  loss  of  weight  of  the  heavy  substance 
being  subtracted  from  the  total  loss.  Example: 

A  fragment  of  wood  weighs 4.3946 

A  fragment  of  lead  weighs 10.6193 

Wood  with  lead  attached  weighs  in  air 15.0139 

Wood  with  lead  attached  weighs  in  water 5.9295 

Loss  of  weight  of  combination 9.0844 

Loss  of  weight  of  lead  in  water  (determined  as  above)  .    .      0.7903 

Loss  of  weight  of  wood 8.2941 

HHj  =  0-529  =  sp.  gr.  of  wood 

The  substance  is  soluble  in  or  decomposable  by  water. — Its  specific 
gravity,  referred  to  some  liquid  not  capable  of  acting  on  it,  is  deter- 
mined, using  that  liquid  as  water  is  used  in  the  case  of  insoluble  sub- 
stances. The  sp.  gr.  so  obtained,  multiplied  by  that  of  the  liquid 
used,  is  the  sp.  gr.  sought.  Example: 

A  piece  of  potassium  weighs 2.576 

A  sp.  gr.  bottle  full  of  naphtha,  sp.  gr".  0.758,  weighs  ....    22.784 

25.360 
The  bottle  with  potassium  and  naphtha  weighs 23.103 

Loss 2.257 

^^  =  1.141  X  0.758  =  0.865  =  sp.  gr.  of  potassium 

LIQUIDS.— The  sp.  gr.  of  liquids  is  determined  by  the  specific 
gravity  balance,  by  the  specific  gravity  bottle,  sometimes  called  pic- 
nometer,  or  by  the  spindle  or  hydrometer. 


6 


MANUAL    OF    CHEMISTRY 


By  the  balance. — The  liquid,  previously  brought  to  the  proper 
temperature,  is  placed  in  the  cylinder  a  (Fig.  2),  and  the  plunger 
immersed  in  it,  and  attached  to  the  arm  of  the  balance.  The 
weights  are  now  adjusted,  beginning  with  the  largest,  until  the 
balance  is  in  equilibrium.  The  sp.  gr.  indicated  by  the  balance  in 
Fig.  2  is  0.998. 

By  the  bottle. — An  ordinary  analytical  balance  is  used.  A  bottle 
of  thin  glass  (Fig.  3),  is  so  made  as  to  contain  a  given  volume  of 
water,  say  100  cc.,  at  15°  C.,  and  its  weight  is  determined  once 
for  all.  To  use  the  picnometer,  it  is  filled  with  the  liquid  to  be  exam- 
ined and  weighed.  The  weight  obtained,  minus  that  of  the  bottle,  is 


FIG.  2. 

the  sp.  gr.  sought,  if  the  bottle  contain  1000  c.c.;  1-10  if  100  c.c., 
etc.  Example:  Having  a  bottle  whose  weight  is  35.35,  and  which 
contains  100  c.c.;  filled  with  urine  it  weighs  137.91,  the  sp.  gr.  of 

the  urine  is  137.91  —  35.35  =  102.56  X  10  =  1025.6 Water  =1000. 

By  the  spindle. — The  method  by  the  hydrometer  is  based  upon  the 
fact  that  a  solid  will  sink  in  a  liquid,  whose  sp.  gr.  is  greater  than  its 
own,  until  it  has  displaced  a  volume  of  the  liquid  whose  weight  is 
equal  to  its  own:  and  all  forms  of  hydrometers  are  simply  contriv- 
ances to  measure  the  volume  of  liquid  which  they  displace  when  im- 
mersed. The  hydrometer  most  used  by  physicians  is  the  urinometer 
(Fig.  4).  It  should  not  be  chosen  too  small,  as  the  larger  the  bulb, 
and  the  thinner  and  longer  the  stem,  the  more  accurate  are  its  indi- 
cations. It  should  be  tested  by  immersion  in  liquids  of  known  sp.  gr., 
and  the  error  at  different  points  of  the  scale  should  be  noted  on  the 


SPECIFIC    GRAVITY 


FIG.  3. 


box.  The  most  convenient  method  of  using  the  instrument  is  as  fol- 
lows: The  cylinder,  which  should  have  a  foot  and  rim,  but  no  pour- 
ing lip,  is  filled  to  within  an  inch  of  the  top;  the  spindle  is  then 
floated  and  the  cylinder  completely  filled  with  the 
liquid  under  examination  (Fig.  4).  The  reading 
is  then  taken  at  the  highest  point  a,  where  the 
surface  of  the  liquid  comes  in  contact  with  the 
spindle.* 

In  all  determinations  of  sp.  gr.  the  liquid  ex- 
amined should  have  the  temperature  for  which 
the  instrument  is  graduated,  as  all  liquids  expand 
with  heat  and  contract  when  cooled,  and,  con- 
sequently, the  result  obtained  will  be  too  low  if 
the  urine  or  other  liquid  be  at  a  temperature 
above  that  at  which  the  instrument  is  intended 
to  be  used,  and  too 
high  if  below  that  tem- 
perature. An  accurate 
correction  may  be  made 
for  temperature  in 
In  a  complex  fluid  like 
the  urine,  however,  this  can  only  be  done 
roughly  by  allowing  1°  of  sp.  gr.  for  each 
3°  C.  (5.4°  F.)  of  variation  in  tempera- 
ture. 

GASES  AND  VAPORS.  —  The  specific 
gravities  of  gases  and  vapors  are  of  great 
importance  in  theoretical  chemistry,  as 
from  them  we  can  determine  molecular 
weights,  in  obedience  to  the  law  of  Avo- 
gadro  (p.  34).  The  student  is  referred  to 
works  on  physics  for  the  methods  used 
for  their  determination. 

Divisibility. —  All  substances  are  cap- 
able of  being  separated,  with  greater  or 
less  facility,  by  mechanical  means  into 
minute  particles.  With  suitable  appara- 
tus, gold  may  be  divided  into  fragments, 
visible  by  the  aid  of  the  microscope,  whose 
weight  would  be  500000^00000  of  a  grain;  and  it  is  probable  that 


simple  solutions. 


FIG.  4. 


when  a  solid  is  dissolved  in  a  liquid  a  still  greater   subdivis 
attained. 

*The  advantages  of  the  method  described  over  that  usually 
reading,  less  liability  to  error,  the  possibility  of  taking  the  reading 
that  readings  are  made  upward,  not  downward. 


opaque 


8 


MANUAL    OF    CHEMISTRY 


Although  we  have  no  direct  experimental  evidence  of  the  existence 
of  a  limit  to  this  divisibility,  we  are  warranted  in  believing  that 
matter  is  not  infinitely  divisible.  A  strong  argument  in  favor  of 
this  view  being  that,  after  physical  subdivision  has  reached  the  limit 
of  its  power  with  regard  to  compound  substances,  these  may  be 
further  divided  into  dissimilar  bodies  by  chemical  means. 

The  limit  of  mechanical  subdivision  is  the  molecule  of  the  physi- 
cist, the  smallest  quantity  of  matter  with  which  he  has  to  deal,  the 
smallest  quantity  that  is  capable  of  free  existence. 

States  of  Matter. —  Matter  may  exist  in  one  of  three  "states": 
solid,  liquid  or  gas.  The  term  fluid  applies  to  both  liquids  and  gases. 
(See  also  p.  19.)  Gases  assume  the  shape  and  size  of  the  contain- 
ing vessel;  liquids  assume  the  shape  of  the  containing  vessel,  but 
have  a  definite  size  ;  solids  are  possessed  of  definite  size  and 
shape. 

Crystallization.  —  Solid  substances  exist  in  two  forms,  amor- 
phous and  crystalline.  In  the  former  they  assume  no  geometric 
shape;  they  conduct  heat  equally  well  in  all  directions;  they  break 
irregularly;  and,  if  transparent,  allow  light  to  pass  through  them 
equally  well  in  ail  directions.  A  solid  in  the  crystalline  form  has 
a  definite  geometrical  shape;  conducts  heat  more  readily  in  some 
directions  than  in  others;  when  broken,  separates  in  certain  direc- 
tions, called  planes  of  cleavage,  more  readily  than  in  others;  and 
modifies  the  course  of  luminous  rays  passing  through  it  differently 
when  they  pass  in  certain  directions  than  when  they  pass  in  others. 

Crystals  are  formed  in  one  of  four  ways:  1.  An  amorphous  sub- 
stance, by  slow  and  gradual  modification,  may  assume  the  crystalline 
form;  as  vitreous  arsenic  trioxid  (q.  v.)  passes  to  the  crystalline 
variety.  2.  A  fused  solid,  on  cooling,  crystallizes;  as  bismuth. 


FIG,  5. 


3.  When  a  solid  is  sublimed  it  is  usually  condensed  in  the  form  of 
crystals.  Such  is  the  case  with  arsenic  trioxid.  4.  The  usual  method 
of  obtaining  crystals  is  by  the  evaporation  of  a  solution  of  the  sub- 
stance. If  the  evaporation  be  slow  and  the  solution  at  rest,  the 
crystals  are  large  and  well-defined.  If  the  crystals  separate  by  the 


CRYSTALLIZATION 


9 


sudden  cooling  of  a  hot  solution,  especially  if  it  be  agitated  during 
the  cooling,  they  are  small. 

Most  crystals  may  be  divided  by  imaginary  planes  into  equal, 
symmetrical  halves.     Such  planes  are  called  planes  of  symmetry. 


FIG.  6. 

Thus  in  the  crystals  in  Fig.  5  the  planes  ab  ab,  ac  ac,  and  be  be  are 
planes  of  symmetry. 

When  a  plane  of  symmetry  contains  two  or  more  equivalent  linear 
directions  passing  through  the  center,  it  is  called  the  principal  plane 
of  symmetry;  as  in  Fig.  6  the  plane  ab  ab,  containing  the  equal 
linear  directions  aa  and  bb. 

Any  normal  erected  upon  a  plane  of  symmetry,  and  prolonged  in 
both  directions  until  it  meets  opposite  parts  of  the  exterior  of  the 
crystal,  at  equal  distances  from  the  plane,  is  called  an  axis  of 
symmetry. 

The  axis  normal  to  the  principal  plane  is  the  principal  axis. 
Thus  in  Fig.  6,  aa,  bb,  and  cc  are  axes  of  symmetry,  and  cc  is  the 
principal  axis. 

Upon  the  relations  of  these  imaginary  planes  and  axes  a  classifi- 
cation of  all  crystalline  forms  into  six  systems  has  been  based. 

I.  The  Cubic,  Regular,  or  Monometric   System. — The  crystals 
of  this  system  have  three  equal  axes,  aa,  bb,  cc,  Fig.  5,  crossing  each 
other  at  right  angles.     The  simple  forms  are  the  cube;  and  its  de- 
rivatives, the  octahedron,  tetrahedron,  and  rhombic  dodecahedron. 
The  crystals  of  this  system  expand  equally  in  all  directions  when 
heated,  and  are  not  doubly  refracting. 

II.  The  Right  Square  Prismatic,  Pyramidal,  Quadratic,  Tetrag- 
onal, or  Dimetric  System  contains  those  crystals  having  three  axes 
placed  at  right  angles  to  each  other— two  as  aa  and  bb,  Fig.  6,  being 
equal  to  each  other  and  the  third,  cc,  either  longer  or  shorter.     The 
simple  forms  are  the  right  square  prism  and  the  right  square  based 
octahedron.     The  crystals  of  this  system  expand  equally  only  in  two 


10 


MANUAL    OF    CHEMISTRY 


directions  when  heated.     They  refract  light  doubly  in  all  directions, 
except  through  one  axis  of  single  refraction. 

III.  The  Rhombohedral  or  Hexagonal  System  includes  crystals 
having  four  axes,  three  of  which  aa,  aa,  aa,  Fig.  7,  are  of  equal 
length  and  cross  each  other  at  60°  in  the  same  plane ;   to  which  plane 
the  fourth  axis,  cc,  longer  or  shorter  than  the  others,  is  at  right 
angles.      The   simple   forms    are   the  regular  six-sided   prism,   the 
regular  dodecahedron,  the  rhombohedron,  and  the  scalenohedron. 
These  crystals  expand  equally  in  two  directions  when  heated,   and 
refract  light  singly  through  the  principal  axis,  but  in  other  directions 
refract  it  doubly. 

IV.  The  Rhombic,  Right  Prismatic,  or  Trimetric  System. — The 
axes  of  crystals  of  this  system  are  three  in  number,  all  at  right  angles 
to  each  other,  and  all  of  unequal  length.     Fig.  6  represents  crystals 
of  this  system,  supposing  aa,  bb,  and  cc  to  be  unequal  to  each  other. 
The   simple   forms   are   the   right   rhombic   octahedron,   the   right 


rhombic  prism,  the  right  rectangular  octahedron,  and  the  right  rec- 
tangular prism.  The  crystals  of  this  system,  like  those  of  the  two 
following,  have  no  true  principal  plane  or  axis. 

V.  The  Oblique,  Monosymmetric,  or  Monoclinic  System. — The 
crystals  of  this  system  have  three  axes,  two  of  which,  aa,  and  cr, 
Fig.  8,  are  at  right  angles;  the  third,  bb,  is  perpendicular  to  one  and 
oblique  to  the  other.  They  may  be  equal  or  all  unequal  in  length. 
The  simple  forms  are  the  oblique  rectangular  and  oblique  rhombic 
prism  and  octahedron. 


CRYSTALLIZATION 


11 


VI.  The  Doubly  Oblique,  Asymmetric,  Triclinic,  or  Anorthic 
System  contains  crystals  having  three  axes  of  unequal  length,  cross- 
ing each  other  at  angles  not  right  angles;  Fig.  8,  aa,  II,  and  cc  being 
unequal  and  the  angles  between  them  other  than  90°. 

The  crystals  of  the  fourth,  fifth,  and  sixth  systems,  when  heated, 
expand  equally  in  the  directions  of  their  three  axes.  They  refract 
light  doubly  except  in  two  axes. 

Secondary  Forms. — The  crystals  occurring  in  nature  or  produced 
artificially  have  some  one  of  the  forms  mentioned  above,  or  some 
modification  of  those  forms.  These  modifications,  or  secondary 


FIG.  8. 

forms,  may  be  produced  by  symmetrically  removing  the  angles  or 
edges,  or  both  angles  and  edges,  of  the  primary  forms.  Thus,  by 
progressively  removing  the  angles  of  the  cube,  the  secondary  forms 
shown  in  Fig.  9  are  produced. 

It  sometimes  happens  in  the  formation  of  a  derivative  form  that 
alternate  faces  are  excessively  developed,  producing  at  length  entire 
obliteration  of  the  others,  as  shown  in  Fig.  10.  Such  crystals  are 
said  to  be  hemihedral.  They  can  be  developed  only  in  a  system 
having  a  principal  axis. 

Isomorphism. — In  many  instances  two  or  more  substances  crystal- 
lize in  forms  identical  with  each  other,  and,  in  most  cases,  such 
substances  resemble  each  other  in  their  chemical  constitution.  They 
are  said  to  be  isomorphous.  This  identity  of  crystalline  form  does 
not  depend  so  much  upon  the  nature  of  the  elements  themselves,  as 
upon  the  structure  of  the  molecule.  The  protoxid  and  peroxid  of 
iron  do  not  crystallize  in  the  same  form,  nor  can  they  be  substituted 
for  each  other  in  reactions  without  radically  altering  the  properties  of 
the  resultant  compound.  On  the  other  hand,  all  that  class  of  salts 
known  as  alums  are  isomorphous.  Not  only  are  their  crystals  iden- 
tical in  shape,  but  a  crystal  of  one  alum,  placed  in  a  saturated 
solution  of  another,  grows  by  regular  deposition  of  the  second  upon 


12 


MANUAL    OF    CHEMISTEY 


its  surface.  Other  alums  may  be  subsequently  added  to  the  crystal,  a 
section  of  which  will  then  exhibit  the  various  salts,  layer  upon  layer. 
Dimorphism. — Although  most  substances  crystallize,  if  at  all,  in 
one  simple  form,  or  in  some  of  its  modifications,  a  few  bodies  are 
capable  of  assuming  two  crystalline  forms,  belonging  to  different 
systems.  Such  are  said  to  be  dimorphous.  Thus,  sulfur,  as  obtained 


FIG.  9. 

by  the  evaporation  of  its  solution  in  carbon  disulfid,  forms  octahedra, 
belonging  to  the  fourth  system.  When  obtained  by  cooling  melted 
sulfur  the  crystals  are  oblique  prisms  belonging  to  the  fifth  system. 
Occasional  instances  of  trimorphism,  of  the  formation  of  crystals 
belonging  to  three  different  systems  by  the  same  substance,  are  also 
known. 

Many  substances  on  assuming  the  crystalline  form,  combine  with 
a  certain  amount  of  water  which  exists  in  the  crystal  in  a  solid 
combination.  Thus  nearly  half  of  the  weight  of  crystallized  alum 
is  water.  This  water  is  called  water  of  crystallization,  and  is  nec- 
essary to  the  maintenance  of  the  crystalline  form,  and  frequently 
to  the  color.  If  blue  vitriol  be  heated,  it  loses  its  water  of  crystal- 
lization, and  is  converted  into  an  amorphous,  white  powder.  Some 
crystals  lose  their  water  of  crystallization  on  mere  exposure  to  the 
air.  They  are  then  said  to  effloresce.  Usually,  however,  they  only 
lose  their  water  of  crystallization  when  heated  (p.  69). 

Allotropy. —  Dimorphism  apart,  a  few  substances  are  known  to 
exist  in  more  than  one  solid  form.  These  varieties  of  the  same 


FIG.  10. 

substance  exhibit  different  physical  properties,  while  their  chemical 
qualities  are  the  same  in  kind.  Such  modifications  are  said  to  be 
allotropic.  One  or  more  allotropic  modifications  of  a  substance  are 
usually  crystalline,  the  other  or  others  amorphous  or  vitreous.  Sul- 
fur, for  example,  exists  not  only  in  two  dimorphous  varieties  of 
crystals,  but  also  in  a  third,  allotropic  form,  in  which  it  is  flexible 


HEAT  13 

and  amorphous.     Carbon  exists  in  three  allotropic  forms:  two  crys- 
talline, the  diamond  and  graphite;  the  third  amorphous. 

In  passing  from  one  allotropic  modification   to  another,  a  sub- 
stance absorbs  or  gives  out  heat. 


PHYSICAL    ACTIONS    OF    CHEMICAL    INTEREST. 
HEAT. 

Change  of  State. —  The  state  of  matter  depends  upon  the  heat 
which  it  contains  and  the  pressure  to  which  it  is  subjected.  If  not 
chemically  decomposed,  solids  are  liquefied,  and  liquids  are  vapor- 
ized by  the  application  of  heat,  as  when  ice  is  converted  into  water 
and  into  steam  by  heat.  The  reverse  change,  as  from  steam  to  ice, 
is  brought  about  by  the  abstraction  of  heat. 

The  generally  accepted  theory  of  heat  is  that  it  is  caused  by  an 
oscillatory  or  vibratory  movement  of  the  molecules  of  matter,  and  that 
this  movement  is  slower  or  more  rapid  as  the  body  contains  a  lesser 
or  greater  "amount  of  heat."  Heat  tends  to  overcome  cohesion,  i.  e., 
the  force  which  unites  adjacent  molecules;  therefore  as  the  rapidity 
of  the  molecular  movement  increases,  the  cohesion  of  the  molecules 
of  the  solid  diminishes,  until  they  move  freely  about  each  other  and 
the  substance  is  liquid,  and,  with  a  still  greater  rapidity  of  molec- 
ular movement  intermolecular  attraction  is  entirely  lost,  the  par- 
ticles tend  to  fly  apart,  and  the  substance  is  a  gas. 

The  effects  of  heat  upon  a  body  are  in  doing  internal  work: 
to  raise  the  temperature  of  the  body,  to  change  its  state,  or  to  cause 
atomic  rearrangement,  i.  e.,  chemical  change;  or  in  doing  external 
work:  in  exerting  pressure  upon  the  containing  vessel,  or  in  trans- 
mitting heat  to  surrounding  bodies. 

Temperature.— The  temperature  of  a  body  is  the  extent  to 
which  it  can  impart  sensible  heat  to  surrounding  bodies, 
not  to  be  confounded  with  the  amount  or  quantity  of  heat  which  the 
body  contains.  A  block  of  ice  just  beginning  to  melt  and  the  same 
weight  of  water  just  beginning  to  freeze  have  the  same  temperature; 
but  heat  must  be  added  to  the  ice  to  continue  its  fusion  and  sub- 
tracted from  the  water  to  continue  its  solidification,  while  during 
both  processes  the  temperature  remains  the  same  in  each. 

Thermometers  are  instruments  for  the  measurement  of  temper- 
ature. They  are  usually  glass  tubes  having  a  bulb  blown  at  one 
end  and  closed  at  the  other,  the  bulb  and  part  of  the  tube  being  filled 
with  mercury  or  with  alcohol,  whose  contraction  or  expansion  indi- 
cates a  fall  or  rise  of  temperature.  The  alcoholic  thermometer  is  used 
for  measuring  low  temperatures,  and  the  mercurial  for  temperatures 


14 


MANUAL    OF    CHEMISTRY 


between  —40°  and  360°  C.  (680°  F. ) .  For  higher  temperatures  instru- 
ments called  pyrometers,  based  upon  the  expansion  of  solids,  are 
used. 

In  every  thermometer  there  are  two  fixed  points ,  determined  by  ex- 
periment. The  lower,  or  freezing  point,  is  fixed  by  immersing  the  in- 
strument in  melting  ice,  and  marking  the  level  of  the  mercury  in  the 
tube  upon  the  glass  when  it  has  become  stationary.  The  higher,  or 
boiling  point,  is  similarly  fixed  by  suspending  the  instrument  in  the 
steam  from  boiling  water.  The  instrument  is  then  graduated  according 
to  one  of  three  scales  :  the  Celsius,  or  Centigrade,  the  Fahrenheit,  and 
the  Reaumur.  The  freezing  point  is  marked  0°  in  the  Centigrade  and 

Reaumur  scales,  and  32°  in  the  Fahren- 
heit. The  boiling  point  is  marked  100° 
in  the  Centigrade,  212°  in  the  Fahrenheit, 
and  80°  in  the  Reaumur  scale  (Fig.  11). 
The  space  between  the  fixed  points  is 
divided  into  100  equal  degrees  in  the 
Centigrade  scale,  into  180°  in  the  Fahren- 
heit, and  in  80°  in  the  Reaumur.  Five 
degrees  Centigrade  are  therefore  equal  to 
nine  degrees  Fahrenheit. 

To  convert  readings  in  one  scale  into 
terms  of  another  the  following  formulas 
are  used: 

Centigrade  to  Fahrenheit:  Multiply  by 
9,  divide  by  5,  and  add  32.  Example: 
50°  C.  X  9  =  450  -5-  5  =  90  +  32  =  122°= 
Ans. 

Fahrenheit  to  Centigrade:  Subtract  32, 
multiply  by  5,  and  divide  by  9.  Example: 
5°F.—  32=  —27X5=  —135-5-9=  -15° 
=  Ans. 

Absolute  Temperature. —  As  temper- 
ature is  merely  one  of  the  manifestations  of  heat,  and  as  heat  is 
considered  as  a  mode  of  motion,  the  absolute  zero  of  temperature 
would  be  reached  when  the  motion  causing  heat  is  completely 
arrested.  This  temperature  is  theoretically  fixed  at  — 273°  C.  There- 
fore —40°  C.  is  233°  on  the  absolute  scale,  and  20°  C.  is  293°. 

Fusion. — When  a  solid,  not  decomposed  by  heat,  is  sufficiently 
heated  it  fuses,  or  melts,  becoming  a  liquid.  Bodies  which  with- 
stand a  high  degree  of  heat  without  fusing  are  said  to  be  refractory. 

Every  substance  begins  to  melt  at  a  certain  temperature,  which  is 
invariable  for  that  substance,  the  pressure  remaining  constant.  This 
temperature  is  called  the  fusing  point  of  the  substance. 


FIG.  11 


HEAT  15 

From  the  moment  fusion  begins  the  temperature  of  the  melting 
body  remains  constant  at  the  fusing  point  until  fusion  is  complete, 
whatever  may  be  the  intensity  of  the  heat  applied. 

The  fusing  point  of  a  substance  is  one  of  the  characteristics 
depended  upon  for  its  identification,  and  frequently  as  a  test  for  its 
purity.  Some  few  substances  pass  by  imperceptible  stages  of  gradual 
softening  from  the  condition  of  solid  to  that  of  liquid,  without  any 
fixed  fusing  point;  this  is  true  of  iron  and  glass. 

The  fusing  point  is  only  very  slightly  influenced  by  the  pressure. 
That  of  bodies  which  contract  on  fusion  is  slightly  lowered  by 
increase  of  pressure.  In  bodies  which  expand  on  fusion  the  fusion 
point  is  slightly  raised  by  increase  of  pressure. 

Latent  heat. — As  during  the  fusion  of  a  solid  there  is  no  increase 
of  temperature,  notwithstanding  that  heat  is  being  constantly  com- 
municated to  the  body,  the  insensible  heat  so  added,  which  really 
does  work,  is  said  to  become  latent.  Each  substance  has  its  own 
latent  heat,  or  latent  heat  of  fusion,  as  it  is  also  called.  Thus,  if 
a  pound  of  water  at  0°C.  be  placed  in  one  vessel,  and  in  another 
similar  vessel  a  pound  of  ice  at  0°C.,  and  the  two  vessels  then 
immersed  in  a  large  vessel  of  hot  water  until  the  ice  is  melted,  the 
temperature  of  the  melted  ice  will  be  found  to  be  0°C.,  while  the 
temperature  of  the  water,  previously  at  0°  will  be  found  to  be 
79.25°  C.;  therefore  the  amount  of  heat  which  became  latent  in 
melting  the  ice  was  79.25°. 

Solution. — A  solid,  liquid  or  gas  is  said  to  dissolve,  or  to  form 
a  solution  with  a  liquid  when  the  two  substances  unite  to  form  a 
homogeneous  liquid.  Solution  may  be  a  purely  physical  process  or 
a  physical  process  attended  by  a  chemical  combination. 

In  simple  or  physical  solution  there  is  no  modification  of  the 
composition  of  the  solvent  or  of  the  dissolved  substance,  and  the 
latter  can  be  reserved,  in  its  primitive  form,  by  simple  evaporation 
of  the  former.  (See  p.  29.)  During  solution,  as  during  fusion  of  a 
solid,  a  certain  amount  of  heat  always  becomes  latent,  and  conse- 
quently physical  solution  of  solids  is  always  attended  by  diminution 
of  temperature. 

In  chemical  solution  there  is  chemical  combination  between  the 
body  dissolved  and  the  solvent,  resulting  in  the  formation  of  a  new 
substance,  which  then  enters  into  solution.  As  chemical  combina- 
tions produce  elevation  of  temperature,  the  temperature  in  chemical 
solution  will  rise,  fall,  or  remain  unchanged  according  as  the  increase 
due  to  combination  is  greater  or  less  than  the  depression  due  to 
liquefaction,  or  the  two  are  equal. 

The  quantity  of  solid,  liquid,  or  gas  which  a  liquid  can  dissolve 
depends  upon  the  following  conditions: 


16  MANUAL    OF    CHEMISTRY 

1.  The  nature  of  the  solvent  and  substance  to  be  dissolved. — The 
solubility  of  a  substance  is  one  of  its  distinguishing  characteristics, 
and  each  substance  has  a  definite  solubility  in  a  given  liquid.     When 
in  speaking  of   solubility  no  solvent  is  mentioned,  water  is  under- 
stood to  be  the  solvent  referred  to. 

2.  The  temperature  usually  has  a  marked  influence  on  the  solubility 
of  a  substance.     As  a  rule,  water  dissolves  a  greater  quantity  of  a 
solid  substance  as  the  temperature  is  increased.      This  increase  in 
solubility  is  different  in  the   case  of   different   soluble    substances. 
Thus  the  increase  in  solubility  of  the  chlorids  of  barium  and  of  po- 
tassium is  directly  in  proportion  to  the  increase  of  temperature.     The 
solubility  of   sodium   chlorid   is  almost  imperceptibly  increased   by 
elevation  of  temperature.     The  solubility  of  sodium  sulfate  increases 
rapidly  up   to    33°   (91.4°  F.),  above   which   temperature    it   again 
diminishes. 

The  solubility  of  gases,  except  hydrogen,  in  water  is  the  greater 
the  lower  the  temperature,  and  the  greater  the  pressure. 

The  amount  of  a  substance  that  a  given  quantity  of  solvent  is 
capable  of  dissolving  at  a  given  temperature  is  fixed.  A  solution 
containing  as  much  of  the  dissolved  substance  as  it  is  capable  of  dis- 
solving is  said  to  be  saturated.  If  made  at  high  temperatures  it  is 
said  to  be  a  hot  saturated,  and  if  at  ordinary  temperatures  a  cold 
saturated  solution. 

If  a  hot  saturated  solution  of  a  salt  be  cooled,  the  solid  is  in  most 
instances  separated  by  crystallization.  If,  in  the  case  of  certain 
substances,  such  as  sodium  sulfate,  however,  the  solution  be  allowed 
to  cool  while  undisturbed  no  crystallization  occurs,  and  the  solution 
at  the  lower  temperature  contains  a  greater  quantity  of  the  solid  than 
it  could  dissolve  at  that  temperature.  Such  a  solution  is  said  to  be 
supersaturated.  The  contact  of  particles  of  solid  material  with  the 
surface  of  a  supersaturated  solution  induces  immediate  crystallization, 
attended  with  elevation  of  temperature. 

3.  The  presence  of  other  substances   already  dissolved. — If   to  a 
saturated  solution  of  potassium  nitrate,  sodium  chlorid  be  added,  a 
further  quantity  of  potassium  nitrate  may  be  dissolved.     In  this  case 
there  is  double  decomposition  between  the  two  salts,  and  the  solution 
contains,  besides  them,  potassium  chlorid  and  sodium  nitrate. 

4.  The  presence  of  a  second  solvent. —  If  two  solvents,  a  and  6, 
incapable  of  mixing  with  each  other,  be  brought  in  contact  with  a 
substance  which  both  are  capable  of  dissolving;   neither  a  nor  b  takes 
up  the  whole  of  the  substance  to  the  exclusion  of  the  other,  however 
greatly  the  solvent  power  or  bulk  of  the  one  may  exceed  that  of  the 
other.     The  relative  quantities  taken  up  by  each  solvent  are  in  a  con- 
stant ratio. 


HEAT  17 

Solidification  or  congelation  is  the  passage  of  a  substance  from 
the  liquid  to  the  solid  state.  It  takes  place  at  a  fixed  temperature, 
which  is  the  same  as  that  of  fusion,  and  which  also  remains  constant 
until  solidification  is  complete.  The  temperature  of  solidification  is 
called  the  freezing  point. 

The  freezing  point  of  a  liquid  holding  a  solid  in  solution  is 
lower  than  that  of  the  pure  solvent.  The  amount  of  lowering  of 
the  freezing  point  is  proportionate  to  the  quantity  of  the  solid 
dissolved;  and  varies  with  equal  quantities  of  different  substances. 
(Seep.  223.) 

When  two  or  more  solids,  having  no  chemical  action  upon  each 
other,  are  dissolved  in  a  given  weight  of  water  the  freezing  point 
is  lowered  by  an  amount  equal  to  the  sum  of  the  depressions  that 
would  be  caused  by  each  separately.  When  the  observed  depression 
in  any  case  is  not  in  accordance  with  the  statement  just  made  it  is 
evidence  that  chemical  action  has  taken  place  between  the  two 
substances. 

Law  of  Raoult. —  If  the  amount  by  which  the  freezing  point  of 
a  solution  containing  a  fixed  quantity  of  a  substance  (1  gm.  in 
100  cc.)  is  lowered  (D)  be  multiplied  by  the  molecular  weight  (p.  38) 
of  that  substance  a  constant  quantity  is  obtained.  This  constant, 
which  is  called  the  coefficient  of  molecular  depression,  and  is 
represented  by  the  symbol  T,  is  19  for  water,  39  for  glacial  acetic 
acid,  and  49  for  benzene.  This  law  is  very  serviceable  for 
determining  the  molecular  weights  of  substances  which  cannot 
be  volatilized  without  decomposition  (p.  223).  Aqueous  solutions 
of  acids,  bases  and  salts  (p.  42)  do  not  obey  the  law  of  Raoult 
(p.  29). 

Vaporization.— The  passage  of  a  liquid  to  the  gaseous  form  may 
take  place  from  the  surface  of  the  liquid  only,  when  the  process  is 
called  evaporation,  or  it  may  take  place  throughout  the  mass  of  the 
liquid,  when  it  is  called  ebullition,  or  boiling. 

Volatile  liquids  are  such  as  evaporate  readily,  as  alcohol,  chloro- 
form, ether.  Fixed  liquids  are  such  as  do  not  evaporate,  as  the 
fixed  oils  and  glycerol. 

Certain  solids,  such  as  iodin,  volatilize  without  passing  through 
the  intermediate  form  of  liquid. 

Evaporation  takes  place  at  all  temperatures,  although  for  some 
substances  there  is  an  inferior  limit  of  temperature  below  which  it 
does  not  occur.  Thus  mercury  gives  off  no  vapor  at  temperatures 
below  —10°. 

Evaporation  is  accelerated  by  (a)  increase  of  temperature;  (b) 
removal  of  the  vapor  from  the  surrounding  atmosphere,  either  by 
renewal  of  the  atmosphere  or  by  the  action  of  absorbents;  (c) 


18  MANUAL    OF    CHEMISTRY 

exposure  of  a  large  surface  of  the  liquid ;  (d)  diminution  of 
pressure. 

Boiling. — At  a  given  pressure  a  liquid  begins  to  boil  at  a  cer- 
tain temperature,  which  varies  in  different  liquids,  but  is  always  the 
same  in  the  same  liquid.  This  temperature  at  760mm.  of  pressure 
is  the  boiling  point  of  the  liquid. 

The  boiling  point  remains  stationary  until  the  liquid  is  com- 
pletely volatilized,  whatever  the  degree  of  the  heat  applied. 

The  boiling  point  is  raised  by  increase  of  pressure,  and  depressed 
by  diminution  of  pressure. 

The  boiling  point  of  a  liquid  holding  in  solution  a  substance 
less  volatile  than  itself  is  higher  than  that  of  the  pure  solvent. 
There  exists  a  relation  between  the  molecular  weight  of  the  sub- 
stance dissolved  and  the  degree  to  which  the  boiling  point  is  raised 
similar  to  the  relation  between  the  molecular  weight  (p.  38)  and  the 
depression  of  the  freezing  point  above  referred  to  (law  of  Raoult), 
which  is  similarly  utilized  in  the  determination  of  molecular  weights 
(p.222). 

Latent  heat  of  vapor. —  The  heat  required  by  a  liquid  to  convert 
it  into  a  vapor,  which  is  insensible  as  temperature,  is  the  latent 
heat  of  vapor  (p.  15). 

A  liquid,  in  evaporating,  absorbs  heat.  It  is  by  this  action  that 
the  human  body  is  cooled  by  the  evaporation  of  perspiration  from 
the  skin,  that  local  anesthesia  is  produced  by  the  evaporation  of 
very  volatile  liquids,  and  that  cold  is  produced  in  refrigerating 
machines. 

Liquefaction  or  condensation  is  the  passage  of  a  gas  or  vapor 
to  the  form  of  a  liquid.  It  is  brought  about  by  chemical  action, 
by  cooling,  and  by  compression. 

Certain  salts,  such  as  calcium  chlorid,  absorb  vapor  of  water 
from  the  air  and  with  it  form  a  solution.  They  are  then  said  to 
deliquesce. 

When  vapors  are  cooled  to  a  temperature  below  the  boiling 
point  of  the  liquid  from  which  they  originated,  at  the  existing 
pressure,  they  are  condensed. 

The  process  of  distillation  consists  in  converting  a  liquid  into  a 
vapor  by  heat  and  subsequently  condensing  the  vapor  by  cooling  it. 
Distillation  under  reduced  pressure  is  frequently  resorted  to  when 
it  is  desirable  to  avoid  a  temperature  as  high  as  the  boiling  point 
of  the  liquid.  Fractional  distillation  is  the  separation  of  liquids 
of  different  boiling  points  by  distillation  and  collection  of  the  several 
fractions  separately. 

Sublimation  is  a  process  differing  from  distillation  in  that  the 
material  acted  upon  and  the  product  are  solid.  Sublimation  may 


HEAT  19 

or  may  not  be  attended  by  fusion  of  the  original  substance.    The 
product  is  called  a  sublimate,  or,  if  in  fine  powder,  flowers. 

Gases  and  vapors. — All  known  gases  and  vapors  have  been 
reduced  to  the  liquid  form  under  the  combined  influences  of  cold 
and  pressure. 

It  has  been  found  that  for  each  gaseous  body  there  exists  a 
certain  temperature,  above  which  no  amount  of  pressure  will  cause 
its  liquefaction,  while  below  that  temperature  it  becomes  a  liquid 
under  sufficient  pressure.  This  temperature  is  called  the  critical 
temperature.  For  example:  the  critical  temperature  of  carbon  dioxid 
is  30.9°,  and  it  is  liquefied  by  a  pressure  of  73  atmospheres  at  30°; 
if  the  gas  at  33°  be  subjected  to  a  pressure  of  100  atmospheres  it 
will  remain  gaseous  until  cooled  to  30.9°,  when  it  will  promptly 
liquefy. 

The  critical  pressure  is  the  pressure  at  which  a  gas  is  liquefied 
when  at  the  critical  temperature. 

Aeriform  bodies  at  temperatures  above  their  critical  temperatures 
are  sometimes  called  true  or  permanent  gases ;  at  temperatures 
below  their  critical  temperatures  they  are  called  vapors. 

Thermal  Unit. — The  most  convenient  unit  to  express  quantities  of 
heat  is  the  amount  of  heat  which  a  given  weight  of  water  absorbs  or 
parts  with  in  changing  its  temperature  by  a  certain  amount.  The 
value  of  this  unit  is  different  in  different  systems :  The  most  generally 
adopted  value  is  called  the  calorie,  and  is  the  amount  of  heat  required 
to  raise  1  kilo,  of  water  through  1  degree  Centigrade.  The  C.G.-S. 
(Centimetre,  Gram,  Second)  value,  sometimes  called  the  small  calorie, 
is  the  amount  of  heat  required  to  raise  1  gram  of  water  through  1 
degree  Centigrade.  In  England  the  unit  is  similarly  based  upon  the 
pound  and  the  degree  Fahrenheit,  and  some  authors  use  a  compromise 
value. 

Specific  Heat.— Equal  weights  of  different  substances  do  not  pos- 
sess the  same  capacity  for  heat.  Thus  if  equal  weights  of  water  and 
of  mercury  be  exposed  to  the  same  source  of  heat  until  the  water 
shall  have  acquired  a  temperature  of  1°  C.,  the  mercury  will  have  a 
temperature  of  30°.  A  given  weight  of  water,  therefore,  requires 
30  times  as  much  heat  to  raise  its  temperature  through  1°  as  does  an 
equal  weight  of  mercury,  and  the  capacity  for  heat  of  mercury  is  sV, 
or  0.0333,  that  of  an  equal  weight  of  water. 

The  specific  heat  of  a  substance  is  the  amount  of  heat  required  to 
raise  the  temperature  of  one  kilo,  of  that  substance  through  one  de- 
gree Centigrade,  expressed  in  calories.  Thus,  the  specific  heat  of 
mercury  is  0.0333,  as  stated  above.  The  specific  heat  of  a  substance 
is,  therefore,  its  capacity  for  heat  as  compared  with  that  of  water 
(p.  37). 


20 


MANUAL    OF    CHEMISTRY 


OSMOSE — DIFFUSION — DIALYSIS 

Diffusion  of  Liquids — Dialysis. — If  a  liquid  be  carefully  floated 
upon  the  surface  of  a  second  liquid,  of  greater  density,  with  which  it 
is  capable  of  mixing,  two  distinct  layers  will  at  first  be  formed.  Even 
at  perfect  rest  mixture  will  begin  immediately,  and  progress  slowly 
until  the  two  liquids  have  diffused  into  each  other  to  form  a  single 
liquid  whose  density  is  the  same  throughout. 

Substances  differ  from  each  other  in  the  rapidity  with  which  they 
diffuse.  Substances  capable  of  crystallization,  crystalloids,  are  much 

more  diffusable  than  those 
which  are  incapable  of  crystal- 
lization— colloids. 

If,  in  place  of  bringing  two 
solutions  in  contact  with  each 
other,  they  be  separated  by  a 
solid  or  semi-solid,  moist,  colloid 
layer,  diffusion  takes  place  in 
the  same  way  through  the  inter- 
posed layer.  The  phenomenon 
is  then  referred  to  as  osmosis. 
Advantage  is  taken  of  this  fact 
to  separate  crystalloids  from 
colloids  by  the  process  of 
dialysis.  The  mixed  solutions 

of  crystalloid  and  colloid  are  brought  into  the  inner  vessel  of  a 
dialyser  (Fig.  12),  whose  bottom  consists  of  a  layer  of  moist 
parchment  paper,  while  the  outer  vessel  is  filled  with  pure  water. 
Water  passes  into  the  inner  vessel,  and  the  crystalloid  passes 
into  the  water  in  the  outer  vessel.  By  frequently  changing 
the  water  in  the  outer  vessel,  solutions  of  the  proteins  or  of 
ferric  hydrate,  etc.,  almost  entirely  free  from  crystalloids,  may  be 
obtained. 

Osmotic  pressure. — It  has  long  been  known  that  in  the  process 
of  osmosis  considerable  pressure  is  exerted  upon  the  walls  of  the 
containing  vessel.  This  is  designated  as  the  osmotic  pressure. 
Recent  investigations  of  the  amount  and  variations  of  this  pressure 
have  shown  that  it  is  equal  to  that  which  would  be  exerted  by  an 
equal  amount  of  the  substance  if  it  were  converted  into  gas,  and 
occupied  the  same  volume,  at  the  same  temperature,  as  the  solution. 
This  discovery  has  afforded  another  method  for  the  determination  of 
molecular  weights,  because  the  osmotic  pressure  is  the  same  in 
solutions  each  containing  a  different  substance  in  the  proportion  of 
its  moleular  weight.  (See  p.  222.) 


FIG.  12. 


LIGHT 


21 


LIGHT. 

The  index  of  refraction  of  substances,  particularly  of  oils  and 
aromatic  organic  liquids,  is  frequently  utilized  for  their  identifica- 
tion, and  has  furnished  data  for  the  determination  of  their  molecu- 
lar structure.  The  index  of  refraction  is  the  ratio  between  the  sine 
of  the  angle  of  incidence  and  the  sine  of  the  angle  of  refraction: 
n  =  '^»  and  is  determined  with  an  instrument  called  a  refracto- 
meter,  or  with  a  suitably  constructed  spectrometer.  As  the  index 
of  refraction  varies  with  the  kind  of  light  used,  and  with  the  sp. 


Pio.  13. 


gr.,  therefore  with  the  temperature,  yellow  (sodium)  light  is  used, 
and  the  temperature  at  which  the  determination  is  made  is  noted 
in  brackets.  The  symbol  n  D  is  used  to  indicate  the  index  of  refrac- 
tion for  sodium  light. 

Spectroscopy. — A  beam  of  white  light,  in  passing  through  a 
prism,  is  not  only  refracted,  or  bent  into  a  different  course,  but  is 
also  dispersed,  or  divided  into  the  different  colors  which  constitute 
the  spectrum  (Fig.  13).  The  red  rays  being  the  least  deflected  are 
the  least  refrangible,  the  violet  rays  being  the  most  deflected  are 
the  most  refrangible. 

A  spectrum  is  of  one  of  three  kinds:  1.  Continuous,  consisting 
of  a  continuous  band  of  colors:  red,  orange,  yellow,  green,  blue, 
cyan -blue,  and  violet.  Such  spectra  are  produced  by  light  from 
white-hot  solids  and  liquids,  from  gas-light,  candle-light,  lime -light, 
and  electric  light.  2.  Bright-line  spectra,  composed  of  bright  lines 
upon  a  dark  ground,  are  produced  by  glowing  vapors  and  gases. 
3.  Absorption  spectra  consist  of  continuous  spectra,  crossed  by 
dark  lines  or  bands,  and  are  produced  by  light  passing  through  a 
solid,  liquid,  or  gas,  capable  of  absorbing  certain  rays.  Examples 
of  bright-line  and  absorption  spectra  are  shown  in  Fig.  14,  p.  22. 


22 


MANUAL    OF    CHEMISTRY 


The  spectrum  of  sunlight  belongs  to  the  third  class.  It  is  not 
continuous,  but  is  crossed  by  a  great  number  of  dark  lines,  known 
as  Fraunhofer's  lines,  the  most  distinct  of  which  are  designated  by 
letters  (No.  1,  Fig.  14). 

The  spectroscope  consists  of  four  essential  parts:  1st,  the  slit, 
a,  Fig.  15,  p.  23;  a  linear  opening  between  two  accurately  straight 


Red.    Orange.    Yellow.      Green. 

tr-"-^/— *— I* **— 

A  rtB  C         D  E  i          F 


Blue. 


Cyan- 
blue.    Violet 


Na. 


K. 


Li. 


Cs. 


Rb. 


Tl. 


In. 


Ga 


II UL 


FIG.  14.    1,  Solar  spectrum;  10  and  11,  Absorption  spectra. 


and  parallel  knife-edges.  2d,  the  collimating  lens,  &;  a  biconvex  lens 
in  whose  principal  focus  the  slit  is  placed,  and  whose  object  it  is  to 
render  the  rays  from  the  slit  parallel  before  they  enter  the  prism. 
3d,  the  prism,  or  prisms,  c,  of  dense  glass,  usually  of  60°,  and  so  placed 
that  its  refracting  edge  is  parallel  to  the  slit.  4th,  an  observing 
telescope,  d,  so  arranged  as  to  receive  the  rays  as  they  emerge  from 


LIGHT 


23 


ie  prisms.     Besides  these  parts  spectroscopes  are  usually  fitted  with 
>me  arbitrary  graduation,  which  serves  to  fix  the  location  of  lines 
>r  bands  observed. 

In  direct  vision  spectroscopes  a  compound  prism  is  used,  so  made 
ip  of  prisms  of  different  kinds  of  glass  that  the  emerging  ray  is 
learly  in  the  same  straight  line  as  the  entering  ray. 

The  micro-spectroscope  (Fig.  16,  p.  24)  is  a  direct  vision  spec- 
troscope used  as  the  eye- piece  of  a  microscope.  With  it  the  spectra 
of  very  small  bodies  may  be  observed. 

As  the  spectra  produced  by  different  substances  are  characterized 
by  the  positions  of  the  lines  or  bands,  some  means  of  fixing  their 
location  is  required.  The  usual  method  consists  in  determining  their 


PIG.  15. 

relation  to  the  principal  Fraunhofer  lines.  As,  however,  the  relative 
positions  of  these  lines  vary  with  the  nature  of  the  substance  of  which 
the  prism  is  made,  although  their  position  with  regard  to  the  colors 
of  the  spectrum  is  fixed,  no  two  of  the  arbitrary  scales  used  will  give 
the  same  reading. 

The  most  satisfactory  method  of  stating  the  positions  of  lines  and 
bands  is  in  wave-lengths.  The  lengths  of  the  waves  of  rays  of 
different  degrees  of  refrangibility  have  been  carefully  determined, 
the  unit  of  measurement  being  the  tenth -metre,  of  which  1010 
make  a  metre.  The  wave- lengths, = A.,  of  the  principal  Fraunhofer 
lines,  are: 


A  7604.00 

a 7185.00 

B  6867.00 

C  .      .  6562.01 


D 5892.12 

E  5269.13 

b  5172.00 

F  .      .  4860.72 


G 4307.25 

Hi 3968.01 

H2 3933.00 


24 


MANUAL    OF    CHEMISTRY 


The  scale  of  wave-lengths  can  easily  be  used  with  any  spectroscope 
having  an  arbitrary  scale,  with  the  aid  of  a  curve  constructed  by 
interpolation.  To  construct  such  a  curve,  paper  is  used  which  is 
ruled  into  square  inches  and  tenths.  The  ordinates  are  marked  with 
a  scale  of  wave-lengths,  and  the  abscisses  with  the  arbitrary  scale  of 
the  instrument.  The  position  of  each  principal  Fraunhofer  line  is 
then  carefully  determined  in  terms  of  the  arbitrary  scale,  and  marked 
upon  the  paper  with  a  X  at  the  point  where  the  line  of  its  wave- 
length and  that  of  its  position  in  the  arbitrary  scale  cross  each  other. 
Through  these  X  a  curve  is  then  drawn  as  regularly  as  possible.  In 
noting  the  position  of  an  absorption -band,  the  position  of  its  centre 
in  the  arbitrary  scale  is  observed,  and  its  value  in  wave-lengths 

obtained  from  the  curve,  which,  of 
course,  can  only  be  used  with  the  scale 
10  and  prism  for  which  it  has  been  made. 
In  the  Zeiss  -  Abbe  microspectroscope 
(Fig.  16)  a  wave-length  scale,  Fig.  17, 
p.  25,  photographed  on  glass  and 
placed  at  N,  is  used  directly.  The 
numbers  on  the  scale  are  the  first  two 
figures  of  those  given  above. 

Polar imetry. —  Light,  in  passing 
through  many  crystals  in  any  direction 
other  than  parallel  to  the  principal  axis 
(p.  9) ,  is  doubly  refracted,  or  bifurcated 
into  two  rays,  the  ordinary  and  extra- 
ordinary, of  equal  intensity.  In  then 
passing  through  a  second,  similar  crys- 
tal, these  rays  are  again  bifurcated, 
forming  four  rays,  which  are  of  equal 
intensity  only  in  two  positions  of  the  second  crystal  with  reference 
to  the  first.  If  the  second  crystal  be  rotated  about  the  common  axis, 
two  of  the  rays  are  gradually  extinguished,  and,  on  further  rotation, 
they  reappear,  and  the  other  two  are  extinguished.  The  light  in 
passing  through  the  first  crystal  has,  therefore,  been  modified  in  such 
manner  that  the  second  crystal  is  opaque  to  the  ordinary  ray  in  one 
position,  and  to  the  extraordinary  ray  in  a  position  opposite  to  the 
first.  Light  so  modified  is  said  to  be  polarized,  and  the  first  crystal 
is  called  the  polarizer,  and  the  second  the  analyzer.  A  Nicol's  prism 
is  a  crystal  of  Iceland  spar,  so  cut  that  it  extinguishes  the  ordinary 
ray,  transmitting  only  the  extraordinary. 

If,  when  the  polarizer  and  analyzer  are  so  adjusted  as  to  extin- 
guish a  ray  passing  through  the  former,  certain  substances  are 
brought  between  them,  light  again  passes  through  the  analyzer;  and 


FIG.  16. 


LIGHT 


25 


in  order  again  to  produce  extinction,  the  analyzer  must  be  rotated 
upon  the  axis  of  the  ray  to  the  right  or  to  the  left.  Substances 
capable  of  thus  influencing  polarized  light  are  said  to  be  optically 
active.  If,  to  produce  extinction,  the  analyzer  is  turned  in  the  direc- 
tion of  the  hands  of  a  watch,  the  substance  is  said  to  be  dextrogyrous; 
if  in  the  opposite  direction,  Icevogyrous. 

The  distance  through  which  the  analyzer  must  be  turned  depends 
upon  the  peculiar  power  of  the  optically  active  substance,  the  length 
of  the  column  interposed,  the  concentration,  if  in  solution,  and  the 
wave-length  of  the  original  ray  of  light.  The  specific  rotary  power 
of  a  substance  is  the  rotation  produced,  in  degrees  and  tenths,  by 


a  B  C 


D 


Eb 


1 

• 

5170 

65 

6< 

3 

5 

5 

5( 

> 

4 

5                                        4C 

i-  i 

I 

1 

1 

1 

1 

1 

FIG.  17. 


one  gram  of  the  substance,  dissolved  in  one  cubic  centimetre  of  a 
non-  active  solvent,  and  examined  in  a  column  one  decimetre  long. 
The  specific  rotary  power  is  determined  by  dissolving  a  known 
weight  of  the  substance  in  a  given  volume  of  solvent,  and  observ- 
ing the  angle  of  rotation  produced  by  a  column  of  given  length. 
Then  let  p  =  weight  in  grams  of  the  substance  contained  in  1  cc. 
of  solution;  I  the  length  of  the  column  in  decimetres;  a  the  angle 
of  rotation  observed;  [a]  the  specific  rotary  power  sought,  we  have 


—  ; 
pi. 

In  most  instruments  monochromatic  light,  corresponding  to  the  D 
line  of  the  solar  spectrum,  is  used,  and  the  specific  rotary  power  for 
that  ray  is  expressed  by  the  sign  [«]D.  The  fact  that  the  rotation 
is  right-handed  is  expressed  by  the  sign  +,  and  that  it  is  left-handed 
by  the  sign  —  . 

It  will  be  seen  from  the  above  formula  that,  knowing  the  value 
of  [a]D  for  any  given  substance,  we  can  determine  the  weight  of 
that  substance  in  a  solution  by  the  formula 


P  = 


26  MANUAL    OF    CHEMISTRY 

The  polarimeter  or  saccharometer  is  simply  a  peculiarly  con- 
structed polariscope,  used  to  determine  the  value  of  a. 

Chemical  effects  of  light. —  Many  chemical  combinations  and 
decompositions  are  much  modified  by  the  intensity,  and  the  kind 
of  light  to  which  the  reacting  substances  are  exposed.  Hydrogen 
and  chlorin  gases  do  not  combine,  at  the  ordinary  temperature,  in 
the  absence  of  light;  in  diffused  daylight  or  gaslight,  they  unite 
slowly  and  quietly;  in  direct  sunlight,  or  in  the  electric  light, 
they  unite  suddenly  and  explosively.  The  salts  of  silver,  used  in 
photography,  are  not  decomposed  in  the  dark,  but  are  rapidly 
decomposed  in  the  presence  of  organic  matter,  when  exposed  to 
sunlight. 

The  chemical  activity  of  the  different  colored  rays  of  which 
the  solar  spectrum  is  composed  is  not  the  same.  Those  which  are 
the  most  refrangible  possess  the  greatest  chemical  activity  —  the 
greatest  actinic  power.  The  visible  solar  spectrum  represents 
only  about  one -third  of  the  rays  actually  emitted  from  the  sun. 
Two -thirds  of  the  spectrum  are  invisible  as  light,  and  are  only 
recognizable  by  their  heating  effects,  or  by  chemical  decomposi- 
tions which  they  provoke. 


ELECTRICITY. 

Galvanic  Electricity. — If  two  plates,  one  of  pure  zinc,  the  other 
of  pure  copper,  be  immersed  in  pure,  dilute  hydrochloric  acid,  in 
such  a  way  that  the  metals  are  not  in  contact  with  each  other,  there 
is  no  action.  But  if  the  two  metals  be  connected,  outside  of  the 
liquid,  by  a  copper  wire,  the  zinc  immediately  begins  to  dissolve,  and 
bubbles  of  hydrogen  gas  are  collected  on,  and  escape  from,  the  sur- 
face of  the  copper,  the  action  continuing  so  long  as  the  wire  connec- 
tion is  maintained,  and  ceasing  so  soon  as  it  is  interrupted.  If  a 
magnetic  compass  be  approached  near  to  the  wire,  while  it  is  con- 
nected with  the  two  plates,  the  needle  will  tend  to  assume  a  position 
at  right  angles  to  the  wire,  whether  the  latter  be  in  an  east  and  west 
position  or  not.  But  if  the  wire  be  disconnected  from  either  plate,  the 
needle  returns  to  its  normal,  north  and  south,  position.  While  the 
two  plates  are  connected  by  the  wire,  an  electrical  current  is  produced 
by  the  chemical  action  between  the  zinc  and  hydrochloric  acid,  and 
passes  through  the  liquid  and  through  the  wire.  A  similar  electrical 
current  is  produced  whenever  two  plates  which  are  conductors  of 
electricity  are  connected  with  each  other  by  a  conducting  wire,  and 
the  free  ends  dipped  into  a  liquid  which  has  a  more  intense  chemical 
action  upon  one  plate  than  upon  the  other.  Such  an  arrangement 


ELECTRICITY  27 

of  plates  and  liquid  is  called  a  galvanic  cell,  and  a  combination  of 
two  or  more  a  battery. 

The  degree  of  difference  between  the  intensity  of  the  chemical 
action  of  the  liquid  upon  the  two  plates  may  be  likened  to  the  differ- 
ence in  level  between  two  vessels  of  water  connected  by  a  pipe.  As 
the  pressure  in  the  water  system  is  the  greater  the  greater  the  differ- 
ence in  level,  so  the  pressure,  or  voltage,  in  the  electrical  system 
is  the  greater  the  greater  the  difference  in  potential  between  two 
points.  As  in  the  water  system  there  is  a  constant  tendency  to 
equalization  of  pressure  by  the  current  flowing  toward  the  lower 
level,  so  in  the  electrical  system  there  is  a  constant  tendency  to 
equalization  of  potential  by  the  flow  of  electrical  current  from  the 
higher  to  the  lower  potential.  The  current  of  electricity  differs 
from  that  of  water,  however,  in  that  it  is  a  flow  of  energy,  not  a 
flow  of  material. 

The  electrical  current  therefore  originates  at  that  plate  having  the 
higher  potential  (the  zinc  plate),  which  is  therefore  called  the  gen- 
erating, or  positive  plate.  It  flows  through  the  liquid  in  the  cell  to 
the  plate  of  lesser  potential  (the  copper  plate),  which  is  therefore 
called  the  collecting,  or  negative  plate.  From  the  negative  plate  the 
current  passes  through  the  outside  wire  toward  the  generating  plate. 
Any  wires  or  other  conductors  connected  with  the  plates  are  called 
poles,  or  electrodes.  As  the  current  leaves  the  cell  from  the  negative 
plate,  the  electrode  connected  with  that  plate  is  of  higher  potential 
than  that  connected  with  the  generating  plate,  and  therefore  we  have 
the  apparent  anomaly  that  the  pole  connected  with  the  negative  plate 
is  called  the  positive  pole,  or  the  anode,  while  the  pole  connected 
with  the  positive  plate  is  called  the  negative  pole,  or  the  cathode. 
The  entire  system  of  cell,  or  cells,  and  outside  conductors  is  called 
the  circuit.  The  circuit  is  said  to  be  closed  when  the  conducting 
circle  is  complete.  It  is  open,  or  broken,  when  it  is  interrupted  at 
any  point. 

The  difference  in  potential  of  an  electric  generator  is  referred 
to  as  its  electromotive  force  (E.M.F.). 

Different  substances  vary  greatly  in  the  amount  of  resistance 
which  they  offer  to  the  passage  of  the  current  through  them.  Those 
through  which  the  current  passes,  with  greater  or  less  facility,  are 
called  conductors;  those  through  which  the  current  will  not  pass 
are  called  insulators.  The  metals  are  good  conductors;  vulcanite 
and  mica  are  insulators. 

The  strength  of  the  current  is  directly  as  the  E.M.F.,  and 
inversely  as  the  resistance,  and,  consequently,  the  current  strength 
is  the  E.M.F.  divided  by  the  resistance  (Ohm's  law). 

In  electrical  measurements  the  following  units  are  used: 


28  MANUAL    OF    CHEMISTRY 

The  ohm  is  the  unit  of  resistance.  It  is  the  resistance  offered 
by  a  column  of  mercury,  at  0°C.,  106.3  cent,  long,  weighing  14.4521 
gru.,  and  having  a  uniform  cross -section  throughout  its  length. 

The  ampere  is  the  unit  of  current  strength.  It  is  a  current 
which  will  deposit  4.025  gm.  of  metallic  silver  in  one  hour  from  a 
neutral  solution  of  silver  nitrate  (see  electrolysis,  below).  A  mil- 
Hamper  e  is  K/OO  ampere. 

The  volt  is  the  unit  of  E.M.F.  It  is  that  E.M.F.  which,  acting 
steadily  through  a  conductor  having  a  resistance  of  one  ohm  will 
produce  a  current  of  one  ampere.  It  is  also  i:iii  the  E.M.F,  of  a 
standard  Clark's  cell  at  15°  C. 

The  coulomb  is  the  unit  of  electrical  quantity.  It  is  the  quan- 
tity of  electricity  transferred  in  one  second  by  a  current  of  one 
ampere. 

The  farad  is  the  unit  of  capacity.  It  is  the  capacity  of  a  con- 
denser charged  to  a  potential  of  one  volt  by  one  coulomb  of 
electricity. 

The  watt  is  the  unit  of  energy.  It  represents  the  work  done 
by  one  ampere  with  a  pressure  of  one  volt.  One  watt  per  second 
is  equal  to  T^G  of  a  horse  power,  or  44.236  foot  pounds.  The 
kilowatt,  1000  watts,  is  the  unit  used  by  electrical  engineers. 

Electrolysis. — When  a  galvanic  current  of  sufficient  power  passes 
through  a  liquid  compound,  or  through  a  solution  of  a  compound, 
capable  of  conducting  the  current,  the  compound  is  decomposed. 
Such  decomposition  is  called  electrolysis,  and  the  substance  so 
decomposed  is  known  as  the  electrolyte. 

When  compounds  are  subjected  to  electrolysis  the  constituent 
elements  are  not  discharged  throughout  the  mass,  although  the  de- 
composition occurs  at  all  points  between  the  electrodes.  In  com- 
pounds made  up  of  two  elements  only,  one  element  is  given  off  at 
each  of  the  poles,  entirely  unmixed  with  the  other,  and,  from  the 
same  compound,  always  from  the  same  pole.  Thus,  if  hydrochloric 
acid  be  subjected  to  electrolysis,  pure  hydrogen  is  given  off  at  the 
negative  pole  and  pure  chlorin  at  the  positive  pole.  In  this  case 
the  hydrogen  is  said  to  be  electropositive,  and  the  chlorin  electro- 
negative. But  if  a  compound  of  chlorin  and  sulfur  be  electrolysed, 
the  chlorin  is  given  off  at  the  negative  pole  and  the  sulfur  at  the 
positive.  Chlorin  is,  therefore,  electronegative  with  regard  to  hydro- 
gen, but  electropositive  with  regard  to  sulfur. 

The  results  of  the  electrolysis  of  binary  compounds  of  the 
different  elements  permits  of  their  arrangement  in  an  electro- 
chemical series,  which  is  given  on  opposite  page  (in  the  shape  of 
a  horseshoe  for  convenience  of  printing).  In  this  series  each 
element  is  electronegative  towards  all  elements  between  it  and  the 


ELECTRICITY 


29 


ELECTRONEGATIVE.         ELECTROPOSITIVE. 


electropositive  end  of  the  list  or  horseshoe,  and  electropositive 
towards  all  between  it  and  the  electronegative  end.  Arbitrarily, 
elements  electronegative  to  hydrogen  in  this  series  are  con- 
sidered as  electronegative  elements, 
those  electropositive  to  hydrogen  as 
electropositive  elements. 

A  similar  decomposition  takes  place 
with  compounds  containing  more  than 
two  elements,  one  element  being  liber-  Bromin 

ated    at    one    pole    and   the    remaining     £0<Jin. 

.      ,  ..  ,,          belenmm 

group    of   elements    separating    at    the     phosphorus 

other.     This  primary  decomposition  is     Arsenic 
generally  modified,  as  to  its  final  pro-     vanadium 
ducts,  by  subsequent  chemical  reactions. 
When,  for  example,  a  solution  of  potas- 


Oxygen 
Sulfur 
Nitrogen 
Fluorin 


Molybdanum 

Tungsten 

Boron 


sium  sulfate  is  electrolysed,  the  liquid  Carbon 

surrounding  the  positive    electrode    be-  An1t.im?ny 

. ,  .  *;.        f  ,      .  Tellurium 

comes  acid  in  reaction  (p.  41),  and  gives  Tantalum 

off  oxygen.    At  the  same  time  the  liquid  Niobium 

at  the  negative   side  becomes  alkaline,  siiicon 

Hydrogen 


iridium 


Ruthenium 


Cesium 
Rubidium 
Potassium 
Sodium 
Lithium 
Barium 
Strontium 
Calcium 
Magnesium 
Beryllium 
Yttrium 
Erbium 
Aluminum 
Zirconium 
Thorium 
Cerium 
Didymium 
Lanthanum 
Manganese 
Zinc 
Iron 
Nickel 
Cobalt 
Thallium 
Cadmium 
Lead 
Indium 

Tin 

Bismuth 


Palladium    Uranium 

Mercury    Copper 

Silver 


and  gives  off  a  volume  of  hydrogen 
double  that  of  the  oxygen  liberated.  In 
the  first  place  the  potassium  sulfate, 
which  consists  of  potassium,  sulfur  and 
oxygen,  is  decomposed  into  potassium, 
which  separates  at  the  negative  pole;  and 
sulfur  and  oxygen,  combined  together, 
which  go  to  the  positive  pole.  The  pot- 
assium liberated  at  the  negative  pole  immediately  decomposes  the 
surrounding  water,  by  a  secondary  action,  forming  potash,  and 
liberating  hydrogen.  The  sulfur  and  oxygen  group  at  the  positive 
pole  also  immediately  reacts  with  water  to  form  sulfuric  acid  and 
liberate  oxygen. 

The  primary  products  of  electrolysis,  whether  consisting  of  one 
element  only  or  of  groups  of  elements,  are  called  ions.  Those  which 
are  separated  at  the  negative  pole,  or  cathode,  are  called  cathions, 
those  which  go  to  the  positive  pole,  or  anode,  are  called  anions. 
The  residues  of  acids  (p.  53)  are  compound  ions,  that  is  ions  con- 
sisting of  more  than  one  element. 

The  phenomena  of  electrolysis  are  explained  by  the  supposition, 
now  generally  accepted,  that  aqueous  solutions  of  acids,  bases  and 
salts  (p.  42)  contain,  not  only  those  compound  substances  (p.  31), 
but  also  their  separated  ions  in  greater  or  lesser  amount,  that  these 
ions,  by  reason  of  their  opposite  electrical  conditions,  are  attracted 


30  MANUAL    OF    CHEMISTRY 

to  the  two  opposite  poles,  and  that,  as  they  are  removed,  a  further 
decomposition  of  the  compound  into  its  ions  occurs.  Thus,  in  the 
above  examples,  the  solution  of  hydrochloric  acid  contains,  not  only 
that  substance,  but  also  the  ions  chlorin  and  hydrogen;  and  the  solu- 
tion of  potassium  sulfate  contains  the  ions  potassium  and  the  sulfur- 
oxygen  group.  This  decomposition  of  substances  in  solution  into 
ions  is  referred  to  as  ionization,  or  as  electrolytic  dissociation 
(p.  44).  The  theory  of  ionization  is  supported  by  observed  varia- 
tions in  the  electrical  conductivity  of  these  substances,  as  well  as  by 
their  departure  from  the  laws  governing  variations  in  freezing  and 
boiling  points  (p.  17),  all  of  which  find  their  explanations  in  this 
hypothesis  (see  also  pp.  44,  45). 

The  same  electrical  current  decomposes  chemically  equivalent 
quantities  of  all  bodies  which  it  traverses  (see  p.  40). 

This  fact  (Faraday's  law)  is  utilized  to  calculate  the  current 
required  to  perform  a  given  chemical  operation.  The  weights  of 
elements  separated  by  a  given  current  are  to  each  other  as  their 
chemical  equivalents;  and  the  quantity  of  a  body  decomposed  in  a 
given  time  is  proportionate  to  the  strength  of  the  current.  Now  a 
current  of  one  ampere,  in  decomposing  water,  liberates  .000010386 
gm.  of  hydrogen  in  one  second.  This  is  the  electrochemical  equiv- 
alent of  hydrogen.  The  electrochemical  equivalent  of  any  other 
element,  i.e.,  the  quantity  of  that  element  separated  by  a  current 
of  one  ampere  in  one  second,  is  obtained  by  multiplying  .000010386 
by  the  chemical  equivalent  of  that  element.  For  example:  taking  the 
chemical  equivalent  of  silver  as  107.7;  .000010386X107. 7^.001118 
gm.  silver  deposited  by  one  ampere  of  current  in  1  sec. = 4. 0248  gm. 
in  one  hour  (see  Ampere,  p.  28). 

Electrolytic  processes  have  now  replaced  older  chemical  methods 
of  manufacture  in  many  branches  of  chemical  industry,  as  in  the 
preparation  of  aluminium,  of  caustic  soda  and  of  bleaching  powder. 


CHEMICAL   COMBINATION. 

Elements. — The  great  majority  of  the  substances  existing  in  and 
upon  the  earth  may  be  so  decomposed  as  to  yield  two  or  more  other 
substances,  distinct  in  their  properties  from  the  substance  from  whose 
decomposition  they  resulted,  and  from  each  other.  If,  for  example, 
sugar  be  treated  with  sulfuric  acid,  it  blackens,  and  a  mass  of  char- 
coal separates.  Upon  further  examination  we  find  that  water  has  also 
been  produced.  From  this  water  we  may  obtain  two  gases,  differing 
from  each  other  widely  in  their  properties.  Sugar  is  therefore  made 
up  of  carbon  and  the  two  gases,  hydrogen  and  oxygen;  but  it  has 


CHEMICAL    COMBINATION  31 

the  properties  of  sugar,  and  not  those  of  either  of  its  constit- 
uent parts.  There  is  no  method  known  by  which  carbon,  hydrogen 
and  oxygen  can  be  split  up,  as  sugar  is,  into  other  dissimilar  sub- 
stances. 

An  element  is  a  substance  which  cannot  by  any  known  means 
be  split  up  into  other  dissimilar  bodies. 

Elements  are  also  called  elementary  substances  or  simple  sub- 
stances. 

The  number  of  well- characterized  elements  at  present  known  is 
seventy -one. 

Laws  governing  the  combination  of  elements. — The  alchemists, 
Arabian  and  European,  contented  themselves  in  accumulating  a  store 
of  knowledge  of  isolated  phenomena,  without,  as  far  as  we  know, 
attempting,  in  any  serious  way,  to  group  them  in  such  a  manner  as 
to  learn  the  laws  governing  their  occurrence.  It  was  not  until  the 
latter  part  of  the  last  century,  1777,  that  Wenzel,  of  Dresden,  im- 
plied, if  he  did  not  distinctly  enunciate,  what  is  known  as  the  law  of 
reciprocal  proportions.  A  few  years  later  Richter,  of  Berlin,  con- 
firming the  work  of  Wenzel,  added  to  it  the  law  of  definite  propor- 
tions, usually  called  Dalton's  first  law.  Finally,  as  the  result  of  his 
investigations  from  1804  to  1808,  Dalton  added  the  law  of  multiple 
proportions,  and  reviewing  the  work  of  his  predecessors,  enunciated 
the  results  clearly  and  distinctly. 

Considering  these  laws,  not  in  the  order  of  their  discovery,  but  in 
that  of  their  natural  sequence,  we  have: 

THE  LAW  OF  DEFINITE  PROPORTIONS. — The  relative  weights 
of  elementary  substances  in  a  compound  are  definite  and  invari- 
able. If,  for  example,  we  analyze  water,  we  find  that  it  is  composed 
of  eight  parts  by  weight  of  oxygen  for  each  part  by  weight  of  hydro- 
gen, and  that  this  proportion  exists  in  every  instance,  whatever  the 
source  of  the  water.  If,  instead  of  decomposing,  or  analyzing  water, 
we  start  from  its  elements,  and  by  synthesis  cause  them  to  unite  to 
form  water,  we  find  that,  if  the  mixture  be  made  in  the  proportion  of 
eight  oxygen  to  one  hydrogen  by  weight,  the  entire  quantity  of  each 
gas  will  be  consumed  in  the  formation  of  water.  But  if  an  excess  of 
either  have  l^een  added  to  the  mixture,  that  excess  will  remain  after 
the  combination. 

Compounds  are  substances  made  up  of  two  or  more  ele- 
ments chemically  united  with  each  other  in  definite  proportions. 
Compounds  exhibit  properties  of  their  own,  which  differ  from 
those  of  the  constituent  elements  to  such  a  degree  that  the  prop- 
erties of  a  compound  can  never  be  deduced  from  a  knowledge  of 
those  of  the  constituent  elements.  Common  salt,  for  instance, 
is  composed  of  39.32  per  cent  of  the  light  bluish-white  metal, 


32  MANUAL    OF    CHEMISTRY 

sodium,  and  60.68  per  cent  of  the  greenish -yellow,  suffocating  gas, 
chlorin. 

Compounds  made  up  of  two  elements  only  are  called  binary 
compounds;  those  consisting  of  three  elements,  ternary  compounds; 
those  containing  four  elements,  quaternary  compounds,  etc. 

A  mixture  is  composed  of  two  or  more  substances,  elements  or 
compounds,  mingled  in  any  proportion,  without  chemical  action 
between  the  constituents.  The  characters  of  a  mixture  may  be 
predicated  from  a  knowledge  of  the  properties  of  its  constituents. 
Thus  sugar  and  water  may  be  mixed  in  any  proportion,  and  the 
mixture  will  have  the  sweetness  of  the  sugar,  and  will  be  liquid 
or  solid,  according  as  the  liquid  or  solid  ingredient  predominates 
in  quantity. 

THE  LAW  OF  MULTIPLE  PROPORTIONS.— When  two  elements 
unite  with  each  other  to  form  more  than  one  compound,  the  result- 
ing compounds  contain  simple  multiple  proportions  of  one  element 
as  compared  with  a  constant  quantity  of  the  other. 

Oxygen  and  nitrogen,  for  example,  unite  with  each  other  to  form 
five  compounds.  In  these  the  two  elements  bear  to  each  other  the 
following  relations  by  weight: 

In  the  first,       14  parts  of  nitrogen  to  8  of  oxygen. 
In  the  second,  14  parts  of  nitrogen  to  8X  2  =  16  of  oxygen. 
In  the  third,     14  parts  of  nitrogen  to  8X3  =  24  of  oxygen. 
In  the  fourth,  14  parts  of  nitrogen  to  8X4  =  32  of  oxygen. 
In  the  fifth,      14  parts  of  nitrogen  to  8X5  =  40  of  oxygen. 

THE  LAW  OP  RECIPROCAL  PROPORTIONS. — The  ponderable  quan- 
tities in  which  substances  unite  with  the  same  substance  express 
the  relation,  or  a  simple  multiple  thereof,  in  which  they  unite  with 
each  other.  Or,  as  Wenzel  stated  it,  "the  weights  &,  &',  b"  of  sev- 
eral bases  which  neutralize  the  same  weight  a  of  an  acid  are  the 
same  which  will  neutralize  a  constant  weight  a  of  another  acid; 
and  the  weights  a,  a',  a"  of  different  acids  which  neutralize  the  same 
weight  b  of  a  base  are  the  same  which  will  neutralize  a  constant 
weight  of  another  base  &'."  For  example:  71  parts  of  chlorin  com- 
bine with  40  parts  of  calcium,  and  16  parts  of  oxygen  also  combine 
with  40  parts  of  calcium,  therefore  71  parts  of  chlorin  combine  with 
16  parts  of  oxygen,  or  the  two  elements  combine  in  the  proportion 
of  some  simple  multiples  of  71  and  16. 

The  Atomic  Theory.— The  laws  of  Wenzel,  Richter,  and  Dalton, 
given  above,  are  simply  generalized  statements  of  certain  groups  of 
facts,  and,  as  such,  not  only  admit  of  no  doubt,  but  are  the  founda- 
tions upon  which  chemistry  as  an  exact  science  is  based.  Dalton, 
seeking  an  explanation  of  the  reason  of  being  of  these  facts,  was  led 


CHEMICAL    COMBINATION  33 

to  adopt  the  view  held  by  the  Greek  philosopher,  Democritus,  that 
matter  was  not  infinitely  divisible.  He  retained  the  name  atom 
(aTo/Ao?=indivisible),  given  by  Democritus  to  the  ultimate  particles, 
of  which  matter  was  supposed  by  him  to  be  composed;  but  rendered 
the  idea  more  precise  by  ascribing  to  these  atoms  real  magnitude,  and 
a  definite  weight,  and  by  considering  elementary  substances  as  made 
up  of  atoms  of  the  same  kind,  and  compounds  as  consisting  of  atoms 
of  different  kinds. 

This  hypothesis,  the  first  step  toward  the  atomic  theory  as  enter- 
tained to-day,  afforded  a  clear  explanation  of  the  numerical  results 
stated  in  the  three  laws.  If  hydrogen  and  oxygen  always  unite 
together  in  the  proportion  of  one  of  the  former  to  eight  of  the  latter, 
it  is  because,  said  Dalton,  the  compound  consists  of  an  atom  of 
hydrogen,  weighing  1,  and  an  atom  of  oxygen,  weighing  8.  If, 
again,  in  the  compounds  of  nitrogen  and  oxygen,  we  have  the  two 

elements  uniting  in  the  proportion  14:8 14:8X2 14:8X3— 

14:8X4 14:8X5,  it  is  because  they  are  severally  composed  of  an 

atom  of  nitrogen  weighing  14,  united  to  1,  2,  3,  4,  or  5  atoms  of 
oxygen,  each  weighing  8.  Further,  that  compounds  do  not  exist  in 
which  any  fraction  of  8  oxygen  enters,  because  8  is  the  weight  of  the 
indivisible  atom  of  oxygen. 

Dalton' s  hypothesis  of  the  existence  of  atoms  as  definite  quantities 
did  not,  however,  meet  with  general  acceptance.  Davy,  Wollaston, 
and  others  considered  the  quantities  in  which  Dalton  had  found  the 
elements  to  unite  with  each  other,  as  mere  proportional  numbers  or 
equivalents,  as  they  expressed  it,  nor  is  it  probable  that  Dalton 's 
views  would  have  received  any  further  recognition  at  that  tinre  had 
their  publication  not  been  closely  followed  by  that  of  the  results  of 
the  labors  of  Humboldt  and  of  Gay  Lussac,  concerning  the  volumes 
in  which  gases  unite  with  each  other. 

In  the  form  of  what  are  known  as  Gay  Lussac 's  laws,  these 
results  are: 

First. — There  exists  a  simple  relation  between  the  volumes  of 
gases  which  combine  with  each  other. 

Second. — There  exists  a  simple  relation  between  the  sum  of 
the  volumes  of  the  constituent  gases,  and  the  volume  of  the  gas 
formed  by  their  union.  For  example: 

1  volume  chlorin  unites  with  1  volume  hydrogen  to  form  2  volumes  hydrochloric 

acid. 
1  volume  oxygen  unites  with  2  volumes  hydrogen  to  form  2  volumes  vapor  of 

water. 

1  volume  nitrogen  unites  with  3  volumes  hydrogen  to  form  2  volumes  ammonia. 
1  volume  oxygen  unites  with  1  volume  nitrogen  to  form  2  volumes  nitric  oxid. 
1  volume  oxygen  unites  with  2  volumes  nitrogen  to  form  2  volumes  nitrous  oxid. 

3 


34  MANUAL    OF    CHEMISTRY 

Berzelius,  basing  his  views  upon  these  results  of  Gay  Lussac, 
modified  the  hypothesis  of  Dalton  and  established  a  distinction 
between  the  equivalents  and  atoms.  The  composition  of  water  he 
expressed,  in  the  notation  which  he  was  then  introducing,  as  being 
H2O,  and  not  HO  as  Dalton's  hypothesis  called  for.  As,  however, 
Berzelius  still  considered  the  atom  of  oxygen  as  weighing  8,  he  was 
obliged  also  to  consider  the  atoms  of  hydrogen  and  of  certain  other 
elements  as  double  atoms  —  a  fatal  defect  in  his  system,  which  led 
to  its  overthrow,  and  to  the  re -establishment  of  the  formula  HO 
for  water. 

It  was  reserved  to  Gerhardt  to  clearly  establish  the  distinction 
between  atom  and  molecule;  to  observe  the  bearing  of  the  discov- 
eries of  Avogadro  and  Ampere  upon  chemical  philosophy;  and  thus 
to  establish  the  atomic  theory  as  entertained  at  present. 

As  a  result  of  his  investigations  in  the  domain  of  organic  chem- 
istry, Gerhardt  found  that,  if  Dalton's  equivalents  be  adhered 
to,  whenever  carbon  dioxid  or  water  is  liberated  by  the  decom- 
position of  an  organic  substance,  it  is  invariably  in  double 
equivalents,  never  in  single  ones.  Always  2CO2  or  2HO,  or 
some  multiple  thereof,  never  CO2  or  HO.  He  further  found  that 
if  the  equivalents  C  =  6,  H  =  l,  and  O  =  8  be  retained,  the 
formula  became  such  that  the  equivalents  of  carbon  are  always 
divisible  by  two.  In  fact,  he  found  the  same  objections  to  apply 
to  the  notation  then  in  use  that  had  been  urged  against  that  of 
Berzelius. 

In  1811,  Avogadro,  from  purely  physical  researches,  had  been 
enabled  to  state  the  law  which  is  now  known  by  his  name,  to 
the  effect  that  equal  volumes  of  all  gases,  under  like  conditions 
of  temperature  and  pressure,  contain  equal  numbers  of  mole- 
cules. 

This  law  is  also  known  as  the  law  of  Ampere,  the  French 
physicist  having  enunciated  it  about  the  same  time  as,  and  inde- 
pendently of,  his  Italian  colaborer. 

In  the  hands  of  Gerhardt  this  law,  in  connection  with  those  of 
Gay  Lussac,  became  the  foundation  of  what  is  sometimes  called 
the  "new  chemistry."  Bearing  in  mind  Avogadro's  law,  we  may 
translate  the  first  three  combinations  given  in  the  table  on  p.  33 
into  the  following: 

1  molecule  chlorin  unites  with  1  molecule  hydrogen,  to  form  2  molecules  hydro- 
chloric acid. 

1  molecule  oxygen  unites  with  2  molecules  hydrogen,  to  form  2  molecules  vapor 
of  water. 

1  molecule  nitrogen  unites  with  3  molecules  hydrogen,  to  form  2  molecules 
ammonia. 


CHEMICAL    COMBINATION  35 

But  the  ponderable  quantities  in  which  these  combinations  take 
place  are: 

35.5  chlorin  to 1  hydrogen. 

16     oxygen  to 2  hydrogen. 

14      nitrogen  to 3  hydrogen. 

And  as  single  molecules  of  hydrogen,  oxygen  and  nitrogen  are  in 
these  combinations  subdivided  to  form  2  molecules  of  hydrochloric 
acid,  water  and  ammonia,  it  follows  that  these  molecules  must  each 
contain  two  equal  quantities  of  hydrogen,  oxygen  and  nitrogen,  less 
in  size  than  the  molecules  themselves.  And,  further,  as  in  these  in- 
stances each  molecule  contains  two  of  these  smaller  quantities,  or 
atoms,  the  relation  between  the  weights  of  the  molecules  must  also 
be  the  relation  between  the  weights  of  the  atoms,  and  we  may  there- 
fore express  the  combinations  thus: 

1  atom  chlorin  weighing  35.5  unites  with  one  1  atom  hydrogen  weighing  1; 
1  atom  oxygen  weighing  16  unites  with  2  atoms  hydrogen  weighing  2  ; 
1  atom  nitrogen  weighing  14  unites  with  3  atoms  hydrogen  weighing  3 ; 

and  consequently,  if  the  atom  of  hydrogen  weighs  1,  that  of  chlorin 
weighs  35.5,  that  of  oxygen  16,  and  that  of  nitrogen  14. 

Atomic  Weight. — The  distinction  between  molecules  and  atoms 
may  be  expressed  by  the  following  definitions: 

A  molecule  is  the  smallest  quantity  of  any  substance  that  can 
exist  in  the  free  state. 

An  atom  is  the  smallest  quantity  of  an  elementary  substance 
that  can  enter  into  a  chemical  reaction. 

The  molecule  is  always  made  up  of  atoms,  upon  whose  nature, 
number  and  arrangement  with  regard  to  each  other,  the  properties  of 
the  substance  depend.  In  an  elementary  substance  the  atoms  compos- 
ing the  molecules  are  the  same  in  kind,  and  usually  two  in  number. 
In  compound  substances  they  are  dissimilar,  and  vary  in  quantity 
from  two  in  a  simple  compound,  like  hydrochloric  acid,  to  hundreds 
or  thousands  in  more  complex  substances. 

The  word  atom  can  only  be  used  in  speaking  of  an  elementary 
body,  and  that  only  while  it  is  passing  through  a  reaction.  The 
term  molecule  applies  indifferently  to  elements  and  compounds. 

The  atoms  have  definite  relative  weights;  and  upon  an  exact  de- 
termination of  these  weights  depend  the  entire  science  of  quantitative 
analytical  chemistry.  (See  Stoichiometry,  p.  47.)  They  have  been 
determined  by  repeated  and  careful  analyses  of  perfectly  pure  com- 
pounds of  the  elements,  and  express  the  weight  of  one  atom  of  the 
element  as  compared  with  the  weight  of  one  atom  of  hydrogen, 
that  being  the  lightest  element  known.  It  is  also  the  weight  of  a 


36 


MANUAL    OF    CHEMISTRY 


volume  of  the  element,  in  the  form  of  gas,  which  would  occupy  the 
same  volume,  under  like  pressure  and  temperature,  as  an  amount 
of  hydrogen  weighing  one.  What  the  absolute  weight  of  an  atom  of 
any  element  may  be  we  do  not  know. 

The  atomic  weight  of  oxygen  is  15.87.  Some  chemists  prefer  a 
system  of  atomic  weights  in  which  that  of  oxygen  is  16;  when  that 
of  hydrogen  becomes  1.008.  The  following  table  contains  a  list  of 
the  elements  at  present  known,  with  their  atomic  weights,  calculated 
with  H  =  1;  and  with  O  =  16.* 


ELEMENTS. 


NAME. 

SYMBOL. 

VALENCE. 

ATOMIC 
WEIGHT,  H=l. 

ATOMIC 
WEIGHT,  O=16. 

Aluminium  

Al 

IV  CAlo")    vi 

26  88 

27  l 

Antimony         

Sb 

III  V 

119  04 

190 

Arcron 

A 

? 

39  68 

40 

Arsonic  

As 

Ill  V 

74  4 

Barium  ....        ... 

Ba 

II 

136  3 

137  4 

Beryllium  (Glucinum)  . 
Bismuth    

Be 
Bi 

II 

III  V 

9.02 
206  8 

9.1 

208  5 

Boron     

B 

III 

10  91 

11 

Bromin  

Br 

I 

79  32 

79  96 

Cadmium  

Cd 

II 

111  5 

H2  4 

Caesium  

Cs 

I 

131.94 

133 

Calcium 

Ca 

II 

39  68 

40 

Carbon 

c 

II  IV 

11  9 

12 

Cerium 

Ce 

n   IV  (Ceo)    vi 

138  89 

140 

Chlorin 

Cl 

I 

35  17 

35  45 

Chromium     

Cr 

II,  IV  (Cr2),  vi 

51.69 

52  1 

Cobalt 

Co 

II   IV  (Co2)    vi 

58  53 

59 

Copper  
Erbium  (  ?  ) 

Cu 
E 

II(Cu2),  ii 
II  fE*l   vi 

63.09 
164  68 

63.6 
166 

Fluorin 

F 

I 

18  85 

19 

Gallium 

Ga 

III  (Ga->)   vi 

69  45 

70 

Germanium      .... 

Ge 

II,  IV 

71  43 

72 

Gold   

Au     \ 

I,  III 

195  63 

197  2 

Helium  

He 

? 

3  97 

4 

Hydrogen  .... 

H 

I 

1  008 

Indium  ....   i^jgrn 
TnrtiTi      .              ^sagftk-  " 

In 
I 

II(Ina),  vi 
I 

113.1 
125  84 

114. 

126  85 

Iridium                   ™ 

Ir 

II    IV  VI 

191  47 

193 

Iron 

Fe 

II  IV  (Feo)   vi 

55  56 

56 

Lanthanum  
Lead       ....       . 

La 
Pb 

III 
II  IV 

136.9 
205  06 

138. 
206  9 

Lithium  

Li 

I 

6  97 

7  03 

Magnesium  .... 

Mg 

II 

24  17 

24  36 

Manganese   

Mn 

II,  IV  (Mn2),  vi 

54  56 

55. 

Mercury    .    .    .    .... 
Molybdenum    
Neodym 

Hg 
Mo 

Nd 

II(Hg2),ii 
II,  IV,  VI 
II 

198.71 
95.24 
142  46 

200.3 
96. 
143  6 

Nickel 

Ni 

II  IV(Nio)   vi 

58  23 

58  7 

Niobium  (Columbium). 

Nb 

93.25 

94. 

*The  atomic  weights  O  =  16  are  those  adopted  by  the  Atomic  Weight  Commission  of  the  Ger- 
man Chemical  Society  for  1900,  and  are  used  in  this  work.  It  is  recommended  that  students  use 
the  nearest  integral  numbers:  i.  e.,  23  for  sodium;  108  for  silver,  etc. 


CHEMICAL    COMBINATION 


37 


ELEMENTS— continued 


NAME. 

SYMBOL. 

VALENCE. 

ATOMIC 
WEIGHT  H=l. 

ATOMIC 
WEIGHT  O=16. 

Nitrogen 

N 

Ill  V 

1Q  QQ 

U04. 

Osmium. 

Os 

II   IV   VI 

IRQ  48 

Oxysren  . 

o 

II 

15  87 

Palladium    

Pd 

II  IV 

105  16 

106 

Phosphorus  
Platinum 

P 
Pt 

III,  V 
II  IV 

30.74 
193  25 

31. 

1Q4   Q 

Potassium 

K 

I 

38  84 

39  15 

Praseodym 

Pr 

II 

139  38 

140  5 

Rhodium 

Rh 

II  IV 

102  18 

103 

Rubidium  . 

Rb 

I 

84  72 

85  4 

Ruthenium  . 

Ru 

II   IV  VI 

100  89 

101  7 

Samarium 

Sa 

III  V 

148  81 

150 

Scandium  

Sc 

IllfSco)   vi 

43  75 

44  1 

Selenium  

Se 

II   IV   VI 

78  47 

79  1 

Silicon  

Si 

II   IV 

28  17 

28  4 

Silver  

AO- 

I 

107  7 

107  93 

Sodium  
Strontium     

Na 

Sr 

I 

II,  IV 

22.87 
86  90 

23.05 
87  6 

Sulfur    

S 

II,  IV,  VI 

31.80 

32  06 

Tantalum  

Ta 

III,  V 

181.54 

183. 

Tellurium  

Te 

II,  IV,  VI 

126. 

127. 

Thallium  

Tl 

I,  III 

202.48 

204.1 

Thorium    

Th 

IV 

230.65 

232.5 

Tin 

Sn 

II  IV 

117  55 

118  5 

Titanium 

Ti 

II   IV 

47  72 

48  1 

Tungsten  

W 

II,  IV,  VI 

182.54 

184. 

Uranium   

u 

II,  IV  (U2),  vi 

237.60 

239.5 

Vanadium     

V 

III,  V(V2),  vi 

50.80 

51.2 

Ytterbium 

Yb 

III 

171.62 

173. 

Ytterium  
Zinc    .    . 

Y 

Zn 

III 
II 

88.29 
64.88 

89. 
65.4 

Zirconium     .    . 

Zr 

II,  IV 

90.00 

90.7 

In  some  cases  the  results  of  analyses  are  such  as  would  agree  with 
two  values  as  the  atomic  weight  equally  well.  In  this  case  we  can 
decide  which  is  the  correct  value  by  the  law  of  Dulong  and  Petit: 
The  product  of  the  specific  heat  (p.  19)  of  any  solid  element  into  its 
atomic  weight  is  approximately  a  constant  number.  This  number, 
known  as  the  atomic  heat,  varies  between  5.39  and  6.87.  When  the 
chemical  relations  indicate  either  one  of  two  numbers  as  the  atomic 
weight,  that  one  is  selected  which,  when  multiplied  by  the  specific 
heat,  gives  an  atomic  heat  within  the  above  limits. 

The  atomic  heats  of  those  elements  which  exist  in  two  or  more 
allotropic  modifications  (p.  12)  vary  in  the  several  forms,  and  at 
different  temperatures,  and  fall  outside  of  the  above  limits.  Thus 
the  atomic  heat  of  crystallized  boron  is  2.11  at  —39.6°,  and  3.99  at 
233.2°,  while  that  of  amorphous  boron  is  2.81;  that  of  the  diamond 
is  0.76  at  —50.5°,  and  5.51  at  985°,  while  that  of  graphite  is  1.37  at 
-50.3°,  and  5. 60  at  978°. 


38  MANUAL    OF    CHEMISTRY 

Molecular  Weight.  —The  molecular  weight  of  a  substance  is 
the  weight  of  its  molecule  as  compared  with  the  weight  of  an 
atom  of  hydrogen.  It  is  also,  obviously,  the  sum  of  the  weights  of 
all  the  atoms  making  up  the  molecule. 

A  very  ready  means  of  determining  the  molecular  weight  of  a 
gaseous  substance  or  of  one  which  may  be  converted  into  vapor,  is 
based  upon  Avogadro's  law.  The  sp.  gr.  of  a  gas  is  the  weight  of  a 
given  volume  as  compared  with  that  of  an  equal  volume  of  hydrogen. 
But  these  equal  volumes  contain  equal  numbers  of  molecules  (p.  34), 
and  therefore,  in  determining  the  sp.  gr.  of  a  gas,  we  obtain  the 
weight  of  its  molecule  as  compared  with  that  of  a  molecule  of 
hydrogen;  and,  as  the  molecule  contains  two  atoms  of  hydrogen, 
while  one  atom  of  hydrogen  is  the  unit  of  comparison,  it  follows  that 
the  specific  gravity  of  a  gas  compared  with  hydrogen,  multiplied 
by  two,  is  its  molecular  weight. 

For  example,  the  gas  acetylene  and  the  liquid  benzene  each  con- 
tain 92.31  per  cent  of  carbon,  and  7.69  per  cent  of  hydrogen;  which 
is  equivalent  to  24  parts,  or  two  atoms  of  carbon;  and  2  parts,  or 
two  atoms  of  hydrogen.  The  sp.  gr.  of  acetylene,  referred  to 
hydrogen  =  2,  is  13;  its  molecular  weight  is,  therefore,  26,  and  its 
molecule  contains  two  atoms  of  carbon  and  two  atoms  of  hydrogen. 
The  sp.  gr.  of  vapor  of  benzene  is  39;  its  molecular  weight  is,  there- 
fore, 78,  and  its  molecule  contains  six  atoms  of  carbon  and  six  atoms 
of  hydrogen. 

When  a  substance  is  not  capable  of  being  volatilized,  its  molecular 
weight  maybe  obtained  from  certain  properties  of  its  solutions,  which 
will  be  considered  in  connection  with  organic  chemistry  (see  p.  221). 

The  vapor  densities  of  comparatively  few  elements  are  known: 

Vapor          Atomic     Molecular 
Density.       Weight.       Weight. 

Hydrogen 1               1  2 

Oxygen 16              16  32 

Sulfur 32               32  64 

Selenium 82              79  164 

Tellurium 130  128  260 

Chlorin 35.5           35.5  71 

Bromin 80              80  160 

lodin 127  127  254 

Phosphorus 63              31  124 

Arsenic 150              75  300 

Nitrogen 14              14  28 

Potassium 39              39  78 

Cadmium 56      '      112  112 

Mercury 100  200  200 

The  atomic  weight  being,  in  most  of  the  above  instances,  equal 
to  the  vapor  density,  and  to  half  the  molecular  weight,  it  may  be 


CHEMICAL    COMBINATION 


inferred  that  the  molecules  of  these  elements  consist  of  two  atoms. 
Noticeable  discrepancies  exist  in  the  case  of  four  elements.  The 
molecular  weights  of  phosphorus  and  arsenic,  as  obtained  from  their 
vapor  densities,  are  not  double,  but  four  times  as  great  as  their 
atomic  weights.  The  molecules  of  phosphorus  and  arsenic  are, 
therefore,  supposed  to  contain  four  atoms.  Those  of  cadmium,  zinc 
and  mercury  contain  but  one  atom. 

Valence  or  atomicity.  —  It  is  known  that  the  atoms  of  different 
elements  possess  different  powers  of  combining  with  and  of  replac- 
ing atoms  of  hydrogen.  Thus: 

1  atom  of  chlorin  combines  with  1  atom  of  hydrogen. 
1  atom  of  oxygen  combines  with  2  atoms  of  hydrogen. 
1  atom  of  nitrogen  combines  with  3  atoms  of  hydrogen. 
1  atom  of  carbon  combines  with  4  atoms  of  hydrogen. 

The  valence,  atomicity,  or  equivalence  of  an  element  is  the 
saturating  power  of  one  of  its  atoms  as  compared  with  that  of 
one  atom  of  hydrogen. 

Elements  may  be  classified  according  to  their  valence  into  — 

Univalent  elements,  or  monads Cl' 

Bivalent  elements,  or  dyads O" 

Trivalent  elements,  or  triads B'" 

Quadrivalent  elements,  or  tetrads Civ 

Quinquivalent  elements,  or  pentads P* 

Sexvalent  elements,  or  hexads "W>i 

Elements  of  even  valence,  i.  e.,  those  which  are  bivalent,  quad- 
rivalent, or  sexvalent,  are  sometimes  called  artiads ;  those  of  uneven 
valence  being  designated  as  perissads. 

In  notation  the  valence  is  indicated,  as  above,  by  signs  placed 
to  the  right  and  above  the  symbol  of  the  element. 

But  the  valence  of  the  elements  is  not  fixed  and  invariable. 
Thus,  while  chlorin  and  iodin  each  combine  with  hydrogen,  atom 
for  atom,  and  in  those  compounds  are  consequently  univalent, 
they  unite  with  each  other  to  form  two  compounds  —  one  containing 
one  atom  of  iodin  and  one  of  chlorin,  the  other  containing  one 
atom  of  iodin  and  three  of  chlorin.  Chlorin  being  univalent,  iodin 
is  obviously  trivalent  in  the  second  of  these  compounds.  Again, 
phosphorus'  forms  two  chlorids,  one  containing  three,  the  other  five 
atoms  of  chlorin  to  one  of  phosphorus. 

In  view  of   these   facts,  we   must   consider  either:   1,  1 
valence  of  an  element  is  that  which  it  exhibits  in  its  most  satnral 
compounds,  as  phosphorus  in  the  pentachlorid,  and  that  the 
compounds  are  non  -  saturated,  and  have  free  valences;   or  2,  t 
the  valence    is  variable.     The   first  supposition  depends  t 


40  •  MANUAL    OF    CHEMISTRY 

upon  the  chances  of  discovery  of  compounds  in  which  the  element 
has  a  higher  valence  than  that  which  might  be  considered  the  max- 
imum to-day.  The  second  supposition  —  notwithstanding  the  fact 
that,  if  we  admit  the  possibility  of  two  distinct  valences,  we  must 
also  admit  the  possibility  of  others  —  is  certainly  the  more  tenable 
and  the  more  natural.  In  speaking,  therefore,  of  the  valence  of  an 
element,  we  must  not  consider  it  as  an  absolute  quality  of  its  atoms, 
but  simply  as  their  combining  power  in  the  particular  class  of  com- 
pounds under  consideration.  Indeed,  compounds  are  known  in  whose 
molecules  the  atoms  of  one  element  exhibit  two  distinct  valences. 
Thus,  ammonium  cyanate  contains  two  atoms  of  nitrogen:  one  in 
the  ammonium  group  is  quinquivalent,  one  in  the  acid  radical  is 
trivalent. 

When  an  element  exhibits  different  valences,  these  differ  from 
each  other  by  two.  Thus,  phosphorus  is  trivalent  or  quinquivalent; 
platinum  is  bivalent  or  quadrivalent. 

The  chemical  equivalent,  or  equivalent  weight,  of  an  element 
is  the  weight  of  that  element  capable  of  combining  with  unit  weight 
of  hydrogen  (or  chlorin).  It  is,  therefore,  its  atomic  weight  divided 
by  its  valence.  We  have  seen  (p.  35)  that  35.5  parts  by  weight  of 
chlorin  combine  with  1  part  by  weight  of  hydrogen,  16  of  oxygen 
with  2  of  hydrogen,  and  14  of  nitrogen  with  3  of  hydrogen. 
Chlorin  being  univalent,  oxygen  bivalent  and  nitrogen  trivalent, 
their  equivalent  weights  are,  therefore,  respectively:  35.5  -5-  1  =  35.5, 
16-^2  =  8,  and  14-^-3  =  4.67. 

Symbols,  Formulae,  Equations. —  Symbols  are  conventional 
abbreviations  of  the  names  of  the  elements,  whose  purpose  it  is  to 
introduce  simplicity  and  exactness  into  descriptions  of  chemical  ac- 
tions. They  consist  of  the  initial  letter  of  the  Latin  name  of  the 
element,  to  which  is  usually  added  one  of  the  other  letters.  If  there 
be  more  than  two  elements  whose  names  begin  with  the  same  letter, 
the  single -letter  symbol  is  reserved  for  the  commonest  element. 
Thus,  we  have  nine  elements  whose  names  begin  with  C;  of  these 
the  commonest  is  Carbon,  whose  symbol  is  C;  the  others  have 
double-letter  symbols,  as  Chlorin,  Cl;  Cobalt,  Co;  Copper,  Cu 
(Cuprum),  etc. 

These  symbols  do  not  indicate  simply  an  indeterminate  quan- 
tity, but  represent  one  atom  of  the  corresponding  element. 

When  more  than  one  atom  is  spoken  of,  the  number  of  atoms 
which  it  is  desired  to  indicate  is  written  either  before  the  symbol  or, 
in  small  figures,  after  and  below  it.  Thus,  H  indicates  one  atom  of 
hydrogen;  2C1,  two  atoms  of  chlorin;  €4,  four  atoms  of  carbon,  etc. 

What  the  symbol  is  to  the  element,  the  formula  is  to  the  com- 
pound. By  it  the  number  and  kind  of  atoms  of  which  the  molecule 


I  CHEMICAL    COMBINATION  41 

3f  a  substance  is  made  up  are  indicated.  The  simplest  kind  of 
formulae  are  what  are  known  as  empirical  formulae,  which  indicate 
3iily  the  kind  and  number  of  atoms  which  form  the  compound.  Thus, 
HCl  indicates  a  molecule  composed  of  one  atom  of  hydrogen  united 
with  one  atom  of  chlorin;  5H2O,  five  molecules,  each  composed  of 
two  atoms  of  hydrogen  and  one  atom  of  oxygen,  the  number  of 
molecules  being  indicated  by  the  proper  numeral  placed  before  the 
formula,  in  which  place  it  applies  to  all  the  symbols  following  it. 
Sometimes  it  is  desired  that  a  numeral  shall  apply  to  a  part  of  the 
symbols  only,  in  which  case  they  are  enclosed  in  parentheses;  thus, 
Al2  (864)3  means  twice  Al  and  three  times  864. 
For  other  varieties  of  formulas,  see  pp.  54,  55. 
Equations  are  combinations  of  formulae  and  algebraic  signs  so 
arranged  as  to  indicate  a  chemical  reaction  and  its  results.  The  signs 
used  are  the  plus  and  equality  signs;  the  former  being  equivalent  to 
"and,"  and  the  second  meaning  "have  reacted  upon  each  other  and 
have  produced."  The  substances  entering  into  the  reaction  are  placed 
before  the  equality  sign,  and  the  products  of  the  reaction  after  it; 
thus,  the  equation 

2KHO+H2S04=K2S04+2H2O 

means,  when  translated  into  ordinary  language:  two  molecules  of 
potash,  each  composed  of  one  atom  of  potassium,  one  atom  of  hydro- 
gen, and  one  atom  of  oxygen,  and  one  molecule  of  sulfuric  acid, 
composed  of  two  atoms  of  hydrogen,  one  atom  of  sulfur,  and  four 
atoms  of  oxygen,  have  reacted  upon  each  other  and  have  produced  one 
molecule  of  potassium  sulfate,  composed  of  two  atoms  of  potassium, 
one  atom  of  sulfur,  and  four  atoms  of  oxygen,  and  two  molecules 
of  water,  each  composed  of  two  atoms  of  hydrogen  and  one  atom 
of  oxygen. 

As  no  material  is  ever  lost  or  created  in  a  reaction,  the  num- 
ber of  each  kind  of  atom  occurring  before  the  equality  sign  in  an 
equation  must  always  be  the  same  as  that  occurring  after  it.  In 
writing  equations  they  should  always  be  proved  by  examining 
whether  the  half  of  the  equation  before  the  equality  sign  contains 
the  same  number  of  each  kind  of  atom  as  that  after  the  equality 
sign.  If  it  do  not  the  equation  is  incorrect. 

The  word  "reaction"  is  used  in  chemistry  in  two  distinct  mean- 
ings: As  applying  to  the  action  mentioned  above,  it  refers  to  the 
mutual  action  of  two  substances  upon  each  other.  In  the  other 
meaning  it  refers  to  the  action  of  substances  upon  certain  organic 
pigments.  Thus,  the  reaction  of  a  substance  is  acid,  when  it  turns 
blue  litmus  red;  alkaline,  when  it  turns  reddened  litmus  blue,  and 
neutral,  when  it  has  no  action  upon  either  blue  or  red  litmus. 


42  MANUAL    OF    CHEMISTRY 

Acids,  Bases,  and  Salts. — All  ternary  and  quarternary  mineral 
substances  have  one  of  three  functions. 

The  function  of  a  substance  is  its  chemical  character  and  rela- 
tionship, and  indicates  certain  general  properties,  reactions  and 
decompositions  which  all  substances  possessing  the  same  function 
possess  or  undergo  alike.  Thus,  in  mineral  chemistry  we  have  acids, 
bases,  and  salts;  in  organic  chemistry  alcohols,  aldehydes,  ketones, 
ethers,  etc. 

An  acid  is  a  compound  of  an  electro-negative  element  or  residue 
with  hydrogen ;  which  hydrogen  it  can  part  with  in  exchange  for 
an  electro-positive  element  without  formation  of  a  base.  An  acid 
has  also  been  denned  as  a  compound  body  which  evolves  water  by 
its  action  upon  pure  caustic  potash  or  soda.  This  latter  definition 
is  undesirable,  in  view  of  the  existence  of  certain  zinc  and  aluminium 
compounds  (pp.  193,  198). 

No  substance  which  does  not  contain  hydrogen  can,  therefore, 
be  called  an  acid. 

The  basicity  of  an  acid  is  the  number  of  replaceable  hydrogen 
atoms  contained  in  its  molecule. 

A  monobasic  acid  is  one  containing  a  single  replaceable  atom 
of  hydrogen,  as  nitric  acid,  HNOs;  a  dibasic  acid  is  one  containing 
two  such  replaceable  atoms,  as  sulfuric  acid,  H^SCU;  a  tribasic  acid 
is  one  containing  three  replaceable  hydrogen  atoms,  as  phosphoric 
acid,  HsPO4.  Polybasic  acids  are  such  as  contain  more  than  one 
atom  of  replaceable  hydrogen. 

Hydracids  are  acids  containing  no  oxygen;  oxacids  or  oxyacids 
contain  both  hydrogen  and  oxygen. 

The  term  base  is  regarded  by  many  authors  as  applicable  to 
any  compound  body  capable  of  neutralizing  an  acid.  It  is,  however, 
more  consistent  with  modern  views  to  limit  the  application  of  the 
name  to  such  ternary  compound  substances  as  are  capable  of 
entering  into  double  decomposition  with  acids  to  form  salts  and 
water.  They  may  be  considered  as  one  or  more  molecules  of  water 
in  which  one -half  of  the  hydrogen  has  been  replaced  by  an  electro- 
positive element  or  radical ;  or  as  compounds  of  such  elements  or 
radicals  with  one  or  more  groups,  OH.  Being  thus  considered  as 
derivable  from  water,  they  are  also  known  as  hydroxids.  They  have 
the  general  formula,  M«(OH)«.  They  are  monatomic,  diatomic, 
triatomic,  etc.,  according  as  they  contain  one,  two,  three,  etc.,  groups 
oxhydryl,  or  hydroxyl  (OH).  As  acids  having  one,  two  or  three, 
etc.,  atoms  of  replaceable  hydrogen  are  designated  as  monobasic, 
dibasic,  or  tribasic  acids,  etc.,  so  bases  having  one  replaceable 
hydroxyl  are  spoken  of  as  monacid  bases,  those  having  two  as 
diacid  bases,  etc. 


CHEMICAL    COMBINATION  43 

The  atomicity  of  a  compound  is  the  number  of  oxhydryls  in 
its  molecule,  which  it  may  lose  by  their  combination  with  the 
hydrogen  of  acids. 

A  double  decomposition  is  a  reaction  in  which  both  of  the 
reacting  compounds  are  decomposed  to  form  two  new  compounds. 

Thiobases,  or  hydrosulfids,  are  compounds  in  all  respects  re- 
sembling the  bases,  except  that  in  them  the  oxygen  of  the  base  is 
replaced  by  sulfur. 

Salts  are  substances  formed  by  the  substitution  of  basylous 
radicals  or  elements  for  a  part  or  all  of  the  replaceable  hydrogen 
of  acids.  They  are  always  formed,  therefore,  when  bases  and  acids 
enter  into  double  decomposition.  They  are  not,  as  was  formerly 
supposed,  formed  by  the  union  of  a  metallic  with  a  non- metallic 
oxid,  but,  as  stated  above,  by  the  substitution  of  one  or  more  atoms 
of  an  element  or  radical  for  the  hydrogen  of  the  acid.  Thus,  the 
compound  formed  by  the  action  of  sulfuric  acid  upon  slaked  lime 
is  not  SOaCaO,  but  CaS04,  formed  by  the  interchange  of  atoms: 

s  \ . ~  s  \ rca 

*'  and  not  f%>  {° 

^  J  Ho  ^ ±12 

2 > 


it  is  therefore,  calcium  sulfate,  and  not  sulfate  of  lime. 

As  salts  are  produced  by  double  decomposition  between  acids  and 
bases  the  latter  play  as  much  part  in  the  formation  of  salts  as  do 
the  former,  and  we  may  also  consider  the  salts  as  substances  formed 
by  the  substitution  of  acid  residues  (p.  53)  for  a  part  or  all  of 
the  oxhydryl  of  bases. 

It  will  be  seen  from  the  above  that  in  some  salts  the  hydrogen 

of  the  acid  is  only  partly  replaced,  as  in  baking  soda.     Such  salts 

are  called  bi  salts  or  acid  salts.     There  exist,  also, 

0_C/O  — Na      salts  in  which  a  portion  of  the  oxhydryl  of  the  bases 

is  retained,  as  white  lead.    Such  salts  are  called  basic 

Baking  Soda.         salts  (Seep>52). 

a~^Pb  The  term  salt,  as  used  at  present,  applies  to  the 

0\pb         compounds  formed  by  the  substitution  of  a  basylous 

0=c/0/  element  for  the  hydrogen  of  any  acid;   and  indeed, 

H-o/Pb         as  used  by  some  authors,  to  the  acids  themselves, 

White  Lead.        which   are  considered  as  salts  of  hydrogen. 

probable,  however,  that  eventually  the  name  will  be 
limited  to  such  compounds  as  correspond  to  acids  whose  molecules 
contain  more  than  two  elements.  Indeed,  from  the  earliest  times  of 
modern  chemistry  a  distinction  has  been  observed  between  the  haloid 
salts,  i.  e.,  those  the  molecules  of  whose  corresponding  acids  consist 


44  MANUAL    OF    CHEMISTRY 

of  hydrogen,  united  with  one  other  element,  on  the  one  hand;  and 
the  oxysalts,  the  salts  of  the  oxacids,  i.  e.,  those  into  whose 
composition  oxygen  enters,  on  the  other  hand.  This  distinction, 
however,  has  gradually  fallen  into  the  background,  for  the  reason 
that  the  methods  and  conditions  of  formation  of  the  two  kinds  of 
salts  are  usually  the  same  when  the  basylous  element  belongs  to  that 
class  usually  designated  as  metallic. 

There  are,  however,  important  differences  between  the  two  classes 
of  compounds.  There  exist  compounds  of  all  of  the  elements  cor- 
responding to  the  hydr acids,  binary  compounds  of  chlorin,  bromin, 
iodin,  and  sulfur.  There  is,  on  the  other  hand,  a  large  class  of  ele- 
ments the  members  of  which  are  incapable  of  forming  salts  corre- 
sponding to  the  oxacids.  No  salt  of  an  oxacid  with  any  one  of  the 
elements  usually  classed  as  metalloids  (excepting  hydrogen)  has  been 
obtained. 

Haloid  salts  may  be  formed  by  direct  union  of  their  constituent 
elements;  oxysalts  are  never  so  produced. 

lonization — Electrolytic  Dissociation. — It  has  been  stated  (pp. 
29,  30)  that  substances  in  solution  which  are  conductors  of  electricity 
are  decomposed  into  their  constituent  ions,  and  that  these  exist  in  the 
solutions  in  greater  or  lesser  amount.  The  ions  are,  moreover,  the 
conductors  of  the  currents,  and  therefore  the  conductivity  of  a  given 
solution  depends  upon  the  number  of  free  ions  which  it  contains;  upon 
the  extent  to  which  ionization  has  taken  place  in  the  solution.  In 
considering  the  relative  conductivity  of  substances  in  solution,  com- 
parison is  made  between  molecular  solutions  or  equivalent  solutions, 
not  percentage  solutions,  and  the  conductivity  is  referred  to  as  mo- 
lecular conductivity,  or  equivalent  conductivity.  Thus  comparisons 
are  made,  not  with  solutions  containing,  for  example,  10  p/m  of  hy- 
drochloric acid  and  of  sulfuric  acid,  but  containing  36.5  HC1  and  98 
H2SO4  per  litre  for  molecular,  or  36.5  HC1  and  49  H2S04  for  equiva- 
lent conductivity.  Molecular  conductivity  (/*)  is  therefore  a  measure 
of  ionization,  and  as  it  increases  with  increase  of  temperature  and 
with  dilution,  electrolytic  dissociation  varies  correspondingly.  The 
influence  of  dilution  is  greater  with  some  substances  than  with  others. 
Thus,  considering  the  molecular  conductivity  of  hydrochloric  acid  in 
a  m/10  solution  at  20°  as  unity,  those  of  sulfuric  acid  and  acetic  acid 
are  0.5  and  0.012  for  solutions  of  like  molecular  concentration.  On 
diluting  to  m/100  the  values  become  1,  0.7  and  0.05;  and  at  m/1000: 
1,  0.9  and  0.12.  The  molecular  conductivity  of  hydrochloric  acid 
varies  very  slightly  with  dilution:  0.95  at  m/10,  0.99  at  m/1000,  while 
that  of  acetic  acid  is  increased  ten  times  by  similar  dilution.  There 
is  also  a  limit  to  the  increase  of  molecular  conductivity  by  dilution,  and 
it  is  believed  that  this  limit  is  reached  when  dissociation  is  complete. 


CHEMICAL    COMBINATION  45 

It  is  inferred  from  these  facts  that  at  m/10  the  ionization  of  hydro- 
chloric acid  is  almost  complete,  while  at  that  dilution  the  solution  of 
acetic  acid  contains  relatively  few  free  ions.  This  explains  why  one 
acid  is  "stronger"  than  another.  If  equal  volumes  of  eq./lO  solutions 
of  hydrochloric,  sulfuric  and  acetic  acids  are  acted  upon  by  equal  quan- 
tities of  a  given  metal,  zinc  for  example,  the  quantity  of  hydrogen 
liberated  from  each,  and  of  metal  dissolved  by  each,  will  be  the  same, 
and  in  that  regard  the  equivalent  quantities  of  the  three  acids  equal 
each  other.  But  if  the  time  consumed  by  the  reactions  be  considered 
the  three  acids  will  be  found  to  differ  in  chemical  activity ;  hydro- 
chloric acid  acting  the  most  rapidly  and  acetic  acid  the  most  slowly. 
It  will  also  be  observed  that  in  chemical  activity  they  vary  in  the 
same  manner  as  they  vary  in  molecular  conductivity,  i.  e.,  in  propor- 
tion to  the  extent  of  their  electrolytic  dissociation ;  and  that  acid  is 
the  strongest,  i.  e.,  has  the  greatest  chemical  activity,  whose  solution 
contains  the  largest  proportion  of  free  ions. 

The  explanation  of  other  important  chemical  phenomena  is  also 
furnished  by  the  hypothesis  of  ionization.  We  have  seen  that  the 
characterizing  quality  of  the  hydrogen  of  acids  is  that  it  is  replaceable 
by  electropositive  elements  (metals),  and  that  the  hydroxyl  of  bases 
is  likewise  replaceable  by  the  residues  of  acids.  These  are  properties 
which  are  peculiar  to  the  hydrogen  atom  and  the  hydroxyl  in  these 
forms  of  combination,  and  many  other  compounds  are  known  contain- 
ing hydrogen  atoms  and  hydroxyl  groups  which  are  not  replaceable 
in  such  manner.  These  marked  differences  in  the  properties  of  hydro- 
gen atoms  (and  of  hydroxyl  groups)  contained  in  solutions  of  acids 
(or  of  alkalies)  from  those  possessed  by  them  when  in  the  form  of 
free  hydrogen  or  in  other  forms  of  combination,  are  considered  to  be 
due  to  their  existence  as  ions  in  such  solutions.  And,  furthermore, 
the  acid  qualities  of  the  hydrogen  in  acids  are  only  manifested  in 
solutions. 

In  the  usual  methods  of  qualitative  analysis  of  mineral  salts  the 
first  step  is  to  bring  the  substance  into  solution.  This  having  been 
done,  the  salt  is  considered  as  made  up  of  two  factors,  a  basic  and 
an  acid  one,  which  are  separately  identified.  Thus,  in  a  solution 
containing  zinc  chlorid  and  copper  sulfate,  the  presence  of  the  zinc 
and  copper  is  first  discovered  by  one  series  of  operations,  and  that 
of  the  chlorin  and  sulfuric  acid  residue  by  another.  The  principle 
underlying  this  method  of  procedure  is  that  in  all  their  forms  of 
combination  in  acid,  base  or  salt,  the  basic  and  acidulous  factors 
each  have  certain  definite  reactions,  irrespective  of  the  nature  of  the 
other  factor  present.  Thus  all  dissolved  metallic  chlorids  and  hydro- 
chloric acid  give  a  white  precipitate  with  silver  nitrate  solution, 
whatever  the  metal  may  be;  and  all  dissolved  saline  compounds  of 


46  MANUAL    OF    CHEMISTRY 

copper  give  a  black  precipitate  with  hydrogen  sulfid  in  acid  solution, 
whatever  the  acid  may  be.  These  facts  are  explained  by  the  sup- 
position that  the  solutions  of  acids,  bases  and  salts  contain  the  free 
ions;  that  solution  of  hydrochloric  acid  contains  the  ions  H  and 
Cl,  and  that  of  copper  sulfate  the  ions  Cu  and  864,  etc.;  and  that 
on  addition  of  a  solution  of  silver  nitrate  to  a  solution  of  zinc 
chlorid  the  ion  Ag  of  the  former  combines  with  ion  Cl  of  the  latter, 
while  the  ions  Zn  and  SO*  also  combine  to  form  ZnSC>4. 

Action  of  Acids  and  Bases  on  Salts,  and  of  Salts  on  each 
other. —  (1)  If  an  acid  be  added  to  a  solution  of  a  salt  whose 
acid  it  nearly  equals  in  chemical  activity,  the  salts  of  both  acids 
and  the  acids  themselves  will  probably  exist  in  the  solution,  pro- 
vided both  acids  and  salts  are  soluble.  Thus,  if  sulfuric  acid  be 
added  to  a  solution  of  potassium  nitrate,  the  solution  will  con- 
tain potassium  sulfate  and  nitrate,  and  sulfuric  and  nitric  acid: 
2H2SO4  +  3KNO3  =  K2SO4  +  KNO3  +  H2SO4  +  2HNO3. 

(2)  If  an  acid  be  added  to  a  solution  of  a  salt  whose  acid  it 
greatly  exceeds  in  activity,  the  salt  is   decomposed,  with  formation 
of  the  salt  of  the  stronger  acid,  and  liberation  of  the  weaker  acid, 
both  salts  and  acids  being  soluble.     Thus,  if  sulfuric  acid  be  added 
to  a  solution   of  sodium   acetate,  the  solution  will  contain  sodium 
sulfate  and  acetic  acid:   H2SO4  +  2NaC2H3O2  =  Na2S04+2HC2H3O2. 

(3)  When  solutions  of  two  salts,  the  acids  of  both  of  which  form 
soluble  salts  with  both  bases,  are  mixed  the  resultant  liquid  contains 
the  four  salts.     Thus,  if  potassium  sulfate  and  sodium  nitrate  be  dis- 
solved in  the   same  solution  it  will  contain  potassium  and  sodium 
sulfates  and   potassium  and   sodium    nitrates:    8X2864+  3NaN03  — 
2K2SO4  +  Na2S04  +  2KNO3  +  NaNOs,  or  in  some  other  proportion. 

In  the  light  of  the  hypothesis  of  ionization,  the  statements  1, 
2  and  3,  while  applying  to  that  portion  of  the  compounds  which 
remain  un- ionized,  may  be  better  expressed  in  the  one:  Solutions  of 
acids,  bases  and  salts  contain  all  the  free  ions.  Thus,  in  the  example 
given  in  3,  the  solution  contains  K,  Na,  SO4,  and  NO3. 

(4)  If  to  a  solution  of  a  salt,   whose  acid   is  insoluble  in  the 
solvent  used,  an  acid  be  added,  capable  of  forming  a  soluble  salt 
with  the  basylous  element,  such  soluble  salt  is  formed  and  the  acid 
is  deposited.     Thus,  if  sulfuric  acid  be  added  to  an  aqueous  solu- 
tion of  sodium  stearate,  stearic  acid  will  be  deposited  and  sodium 
sulfate  formed:   H2SO4  +  2NaCi8H35O2  =  Na2SO4  +  2HCi8H35O2. 

(5)  If,  to  a  solution  of  a  salt,  an  acid  be  added  which  is  capa- 
ble of  forming  an  insoluble  salt  with  the  base,  such  insoluble  salt 
is  formed  and  precipitated.     Thus,  if  sulfuric  acid  be   added  to  a 
solution  of  barium  nitrate,  barium  sulfate  is  precipitated  and  nitric 
acid  liberated:   H2SO4  +  Ba(NO3)2  =  BaSO4  +  2HNO3. 


CHEMICAL    COMBINATION  47 

(6)  If  to  a  solution  of  a  salt  whose  basylous  element  is  insol- 
uble  a  soluble   base   be  added,  capable  of   forming   a  soluble   salt 
with  the  acid,  such  soluble  salt  is  formed,  with  precipitation  of  the 
insoluble  base.     Thus,  if  potassium  hydroxid  be  added  to  a  solution 
of   cupric   sulfate,    cupric   hydroxid   is    precipitated   and   potassium 
sulfate  formed:   2KHO  +  CuSO4  =  Cu(HO)2  +  K2SO4. 

(7)  If  a  base  be  added  to  a  solution  of  a  salt  with  whose  acid  it  is 
capable  of  forming  an  insoluble  salt,  such  insoluble  salt  is  formed 
and  precipitated,  and  the  base  of  the  original  salt,  if  insoluble,  is 
also   precipitated.     Thus  if   solutions    of   barium    hydroxid  and  of 
potassium  sulfate  be  mixed,  barium  sulfate  is  precipitated  and  the 
solution  contains  potassium  hydroxid:   Ba(HO)2-|-K2S04  =  BaS04-j- 
2KHO;    or  if   solutions  of   barium  hydroxid  and  silver  sulfate  be 
mixed  both  barium  sulfate  and  silver  hydroxid  will  be  precipitated: 
Ba(HO)2-f  Ag2SO4=BaSO4+2AgHO,  and  if  the  substances  be  used 
in  the  proportions  given  in  the  equation  pure  water  will  remain. 

(8)  If  solutions  of  two  salts,  the  acid  of  one  of  which  is  capable  of 
uniting  with  the  base  of  the  other  to  form  an  insoluble  salt,  be  mixed, 
such   insoluble  salt   is  precipitated.      Thus,  if  solutions  of  barium 
nitrate  and  of  sodium  sulfate  be  mixed,  barium  sulfate  is  precipitated 
and  sodium  nitrate  formed:    Ba(NO3)2+Na2SO4=BaSO4H-2NaNO3. 

The  statements  4  to  8  may  be  summarized  in  the  statement: 
When  solutions  of  acids,  bases  or  salts  any  of  whose  ions  are  capable 
of  uniting  to  form  an  insoluble  compound  are  mixed,  such  insoluble 
compound  is  formed  and  precipitated. 

(9)  If  to  a  salt  whose  acid  is  volatile  at  the  existing  temperature, 
an  acid  capable  of  forming  with  the  basylous  element  a  salt  fixed  at 
the  same  temperature  be  added,   the  fixed  salt  is  formed  and  the 
volatile  acid  expelled.     Thus,  with  the  application  of  heat,  sulfuric 
acid  expels  nitric  acid  from  sodium  nitrate  to  form  sodium  sulfate: 
H2SO4+2NaNO3=2HNO3+Na2SO4. 

(10)  Similarly,  a  volatile  base  is  expelled  from  its  salts  by  a  fixed 
one.     Thus  caustic  potash  and  ammonium  chlorid  form  ammonia, 
water  and  potassium  chlorid:     KHO+NH4C1=KC1+NH3+H2O. 

Stoichiometry  (o-rotxetov=an  element;  ^eVpov=a  measure)— in  its 
strict  sense  refers  to  the  law  of  definite  proportions,  and  to  its  appli- 
cations. In  a  wider  sense,  the  term  applies  to  the  mathematics  of 
chemistry,  to  those  mathematical  calculations  by  which  the  quantita- 
tive relations  of  substances  acting  upon  each  other,  and  of  the  prod- 
ucts of  such  reactions  are  determined. 

A  chemical  reaction  can  always  be  expressed  by  an  equation, 
which,  as  it  represents  not  only  the  nature  of  the  materials  involved, 
but  also  the  number  of  molecules  of  each,  is  a  quantitative  as  well  as 
a  qualitative  statement. 


48  MANUAL    OF    CHEMISTRY 

Let  it  be  desired  to  determine  how  much  sulfuric  acid  will  be  re- 
quired to  completely  decompose  100  parts  of  sodium  nitrate,  and  what 
will  be  the  nature  and  quantities  of  the  products  of  the  decomposition. 
First  the  equation  representing  the  reaction  is  constructed : 

H2SO4          -4-          2NaNO3  Na2SO4          +          2HNO3 

Sulfuric  acid.  Sodium  nitrate.  Disodic  sulfate.  Nitric  acid. 

which  shows  that  one  molecule  of  sulfuric  acid  decomposes  two  mole- 
cules of  sodium  nitrate,  with  the  formation  of  one  molecule  of  sodium 
sulfate  and  two  of  nitric  acid.  The  quantities  of  the  different  sub- 
stances are,  therefore,  represented  by  their  molecular  weights,  or 
some  multiple  thereof,  which  are  in  turn  obtained  by  adding  together 
the  atomic  weights  of  the  constituent  atoms: 

H2S04          +          2NaNO3  Na2SO4          4-          2HNO3 

1X2=  2  23X1=23  23X2=46  1X1=  1 

32X1=32  14X1=14  32X1=32  14X1=14 

16X4=64  16X3=48  16X4=64  16X3=48 

98                             85X2=170  142                             63X2=126 

Consequently,  98  parts  H2S04  decompose  170  parts  NaNO3,  and 
produce  142  parts  Na2SO4,  and  126  parts  HNO3.  To  find  the  result 
as  referred  to  100  parts  NaNOs,  we  apply  the  simple  proportion : 


170 

170 
170 


100 
100 
100 


98 
142 
126 


57.64  — 57. 64  =  parts  H2SO4  required. 
83.53  —  83.53=     "      Na2SO4  produced. 
74.11  —  74.11=    "      HNO3  " 


As  in  writing  equations  (see  p.  41),  the  work  should  always  be 
proved  by  adding  together  the  quantities  on  each  side  of  the  equality 
sign,  which  should  equal  each  other:  98+170=268=142+126=268, 
or  57.64  +  100  =  157.64  =  83.53  +  74.11  =  157.64. 

In  determining  quantities  as  above,  regard  must  be  had  to  the 
purity  of  the  reagents  used,  and,  if  they  be  crystallized,  to  the 
amount  of  water  of  crystallization  (see  p.  12)  they  contain. 

Let  it  be  desired  to  determine  how  much  crystallized  cupric  sul- 
fate can  be  obtained  from  100  parts  of  sulfuric  acid  of  92  per  cent 
strength.  As  cupric  sulfate  crystallizes  with  five  molecules  of  water 
of  crystallization  the  reaction  occurs  according  to  the  equation: 

H2SO4         +        CuO          +          4H2O        =  CuSO45Aq. 

Sulfuric  acid.  Cupric  oxid.  Water.  Cupric  sulfate. 

63  1X2=    2                    63X1  =  63 

1X2=    2                     16  16X1  =  16                    32X1  =  32 

32X1  =  32  16X4  =  64 

16X4  =  64  18X5  =  90 

98        79  18X4  =  72       249 

98  +  79  +  72  =  249 


CHEMICAL    COMBINATION  49 

98  parts  of  100  per  cent  H2SO4  will  produce,  therefore,  249  parts 
of  crystallized  cupric  sulfate.  But  as  the  acid  liquid  used  contains 
only  92  parts  of  true  H2SO4,  in  100;  100  parts  of  such  acid  will 
yield  233.75  parts  of  crystallized  sulfate,  for  98:92: : 249: 233.75. 

In  gravimetric  quantitative  analysis  the  substance  whose  quan- 
tity is  to  be  determined  is  converted  into  an  insoluble  compound, 
which  is  then  purified,  dried,  and  weighed,  and  from  this  weight 
the  desired  result  is  calculated. 

Let  the  problem  be  to  determine  what  percentage  of  silver  is 
contained  in  a  silver  coin.  Advantage  is  taken  of  the  formation 
of  the  insoluble  silver  chlorid.  A  piece  of  the  coin  is  chipped 
off  and  weighed:  weight  of  coin  used  =  2. 5643  grams.  The  chip  is 
then  dissolved  in  nitric  acid,  forming  a  solution  of  silver  nitrate. 
From  this  solution  the  silver  is  precipitated  as  chlorid,  by  the 
addition  of  hydrochloric  acid,  according  to  the  equation: 

AgNO3  +  HCl        =  AgCl  +  HNO3 

Silver  nitrate.  Hydrochloric  acid.        Silver  chlorid.  Nitric  acid. 

108X1  =  108  1  108  1X1=    1 

14X1=    14  35.5  35.5  14X1  =  14 

16X3=    48  16X3  =  48 


170  36.5  143.5  63 

170  -f  36.5  =  206.5  =  143.5  +  63. 

The  silver  chlorid  is  collected,  dried  and  weighed: 

Weight  of  coin  used 2.5643  grams. 

Weight  of  AgCl  obtained 3.0665 

as  143.5  grams  AgCl  contain  108  grams  Ag  — 143.5:108: :  3.0605: 
2.3078  —  2.5643  grams  of  the  coin  contain  2.3078  grams  of  silver, 
or  90  per  cent —  2.5643:100: : 2. 3078: 90. 

Nomenclature.— The  names*  of  the  elements  are  mostly  of  Greek 
derivation,  and  have  their  origin  in  some  prominent  property  of  the 
substance.  Thus,  phosphorus,  </>^s,  light,  and  <£epeiv,  to  bear.  Some 
are  of  Latin  origin,  as  silicon,  from  silex,  flint;  some  of  Gothic 
origin,  as  iron,  from  iarn;  and  others  are  derived  from  modern 
languages,  as  potassium  from  pot-ash.  Very  little  system  has  been 
followed  in  naming  the  elements,  beyond  applying  the  termination 
ium  to  the  metals,  and  in  or  on  to  the  non-metals;  and  even  to  this 
rule  we  find  such  exceptions  as  a  metal  called  manganese  and  a 
non-metal  called  sulfur. 

The  names  of  compound  substances  were  formerly  chosen  upon 
the  same  system,  or  rather  lack  of  system,  as  those  of  the  elements. 

*For  rules  governing  orthography  and  pronunciation  of  chemical  terms,  see  Appendix  A. 


50  MANUAL    OF    CHEMISTRY 

So  long  as  the  number  of  compounds  with  which  the  chemist  had 
to  deal  remained  small,  the  use  of  these  fanciful  appellations,  con- 
veying no  more  to  the  mind  than  perhaps  some  unimportant  quality 
of  the  substances  to  which  they  applied,  gave  rise  to  comparatively 
little  inconvenience.  In  these  later  days,  however,  when  the  number 
of  compounds  known  to  exist,  or  whose  existence  is  shown  by 
approved  theory  to  be  possible,  is  practically  infinite,  some  system- 
atic method  of  nomenclature  has  become  absolutely  necessary. 

The  principle  of  the  system  of  nomenclature  at  present  used 
is  that  the  name  shall  convey  the  composition  and  character  of 
the  substance. 

Compounds  consisting  of  two  elements,  or  of  an  element  and  a 
radical  only,  binary  compounds,  are  designated  by  compound  names 
made  up  of  the  name  of  the  more  electro -positive,  followed  by  that 
of  the  more  electro -negative,  in  which  the  termination  id  has  been 
substituted  for  the  termination  in,  on,  ogen,  ygen,  orus,  ium,  and  ur. 
For  example:  the  compound  of  potassium  and  chlorin  is  called  potas- 
sium chlorid,  that  of  potassium  and  oxygen  potassium  oxid,  that  of 
potassium  and  phosphorus  potassium  phosphid. 

In  a  few  instances  the  older  name  of  a  compound  is  used  in  prefer- 
ence to  the  one  which  it  should  have  under  the  above  rule,  for  the 
reason  that  the  substance  is  one  which  is  typical  of  a  number  of  other 
substances,  and  therefore  deserving  of  exceptional  prominence.  Such 
are  ammonia,  NHa;  water,  H2O. 

When,  as  frequently  happens,  two  elements  unite  with  each  other 
to  form  more  than  one  compound,  these  are  usually  distinguished 
from  each  other  by  prefixing  to  the  name  of  the  element  varying  in 
amount  the  Greek  numeral  corresponding  to  the  number  of  atoms  of 
that  element,  as  compared  with  a  fixed  number  of  atoms  of  the  other 
element. 

Thus,  in  the  series  of  compounds  of  nitrogen  and  oxygen,  most  of 
which  contain  two  atoms  of  nitrogen,  N2  is  the  standard  of  compari- 
son, and  consequently  the  names  are  as  follows: 

N2O  =  Nitrogen  monoxid. 

NO   (=N2O2)  =  Nitrogen  dioxid. 
N2O3  =  Nitrogen  trioxid. 

NO2  (=N2O4)  =  Nitrogen  tetroxid. 
N2O5  =  Nitrogen  pentoxid. 

Another  method  of  distinguishing  two  compounds  of  the  same 
two  elements  consists  in  terminating  the  first  word  in  ous  in  that 
compound  which  contains  the  less  proportionate  quantity  of  the  more 
electro -negative  element,  and  in  ic  in  that  containing  the  greater  pro- 
portion ;  thus : 


CHEMICAL    COMBINATION  51 

502  =  Sulfurows  oxid. 

503  =  Sulfuric  oxid. 

Hg2Cl2  (2Hg  :  2C1)  =  Mercimms  chlorid. 
HgClo    (2Hg  :  4C1)  =  Mercuric  chlorid. 

This  method,  although  used  to  a  certain  extent  in  speaking  of  com- 
pounds composed  of  two  elements  of  Class  II  (see  p.  57),  is  used 
chiefly  in  speaking  of  binary  compounds  of  elements  of  different 
classes. 

In  naming  the  oxacids  the  word  acid  is  used,  preceded  by  the  name 
of  the  electro -negative  element  other  than  oxygen,  to  which  a  prefix 
or  suffix  is  added  to  indicate  the  degree  of  oxidation.  If  there  be  only 
two,  the  least  oxidized  is  designated  by  the  suffix  ous,  and  the  more 
oxidized  by  the  suffix _ic,  thus: 

HNO2  =  Nitrous  acid. 
HNO3  =  Nitric  acid. 

If  there  be  more  than  two  acids,  formed  in  regular  series,  the  least 
oxidized  is  designated  by  the  prefix  hypo  and  the  suffix  ous;  the  next 
by  the  suffix  ous;  the  next  by  the  suffix  ic;  and  the  most  highly 
oxidized  by  the  prefix  per  and  the  suffix  ic;  thus: 

HC1O  =  Hypochlorous  acid. 
HC1O2  =  Chlorous  acid. 
HC1O3  =  Chloric  acid. 
HC1O4  =  Perchloric  acid. 

Certain  elements,  such  as  sulfur  and  phosphorus,  exist  in  acids 
which  are  derived  from  those  formed  in  the  regular  way,  and  which 
are  specially  designated. 

The  names  of  the  oxy salts  are  derived  from  those  of  the  acids  by 
dropping  the  word  acid,  changing  the  termination  of  the  other  word 
from  ous  into  ite,  or  from  ic  into  ate,  and  prefixing  the  name  of  the 
electro -positive  element  or  radical;  thus: 

HN02  KN02 

Nitrous  acid.  Potassium  nitrite. 

'  HN03  KN03 

Nitric  acid.  Potassium  nitrate. 

HC10  KC10 

Hypochlorows  acid.  Potassium  hypochlorite. 

Acids  whose  molecules  contain  more  than  one  atom  of  replace- 
able hydrogen  are  capable  of  forming  more  than  one  salt  with  electro- 
positive elements,  or  radicals,  whose  valence  is  less  than  the  basicity 
of  the  acid.  Ordinary  phosphoric  acid,  for  instance,  contains  in  each 
molecule  three  atoms  of  basic  hydrogen,  and  consequently  is  capable 


52  MANUAL    OF    CHEMISTRY 

of  forming  three  salts  by  the  replacement  of  one,  two,  or  three  of  its 
hydrogen  atoms,  by  one,  two,  or  three  atoms  of  a  univalent  metal. 
To  distinguish  these  the  Greek  prefixes  mono,  di,  and  tri  are  used,  the 
termination  ium  of  the  name  of  the  metal  being  changed  to  ic,  thus: 

H2KPO4  =  Ifowopotassic  phosphate. 
HK2PO4  =  Dipot&ssic  phosphate. 
K3PO4     =  Tripotassic  phosphate. 

The  first  is  also  called  dihydropotaasic  phosphate,  and  the  second, 
hydrodipotsissic  phosphate. 

In  the  older  works,  salts  in  which  the  hydrogen  has  not  been 
entirely  displaced  are  sometimes  called  bisalts  (bicarbonates),  or  acid 
salts  ;  those  in  which  the  hydrogen  has  been  entirely  displaced  being 
designated  as  neutral  salts. 

Some  elements,  such  as  mercury,  copper,  and  iron,  form  two  dis- 
tinct series  of  salts.  These  are  distinguished,  in  the  same  way  as  the 
acids,  by  the  use  of  the  suffix  ous  in  the  names  of  those  containing 
the  less  proportion  of  the  electro  -negative  group,  and  the  suffix  ic  in 
those  containing  the  greatest  proportion,  e.g.: 

(Cu2)SO4    ............      (1SO4  :  2Cu)  =  Cuprdzw  sulfate. 

CuSO4     .............      (2SO4  :  2Cu)  =Cupric  sulfate. 


FeSO4     .............      (2SO4  :  2Fe)  =Ferr0MS  sulfate. 

(Fe2)(SO4)3  ........  '  ,    .    .      (3SO4  :  2Fe)  =  Feme  sulfate. 

The  names,  basic  salts,  subsalts  and  oxysalts  have  been  applied 
indifferently  to  salts,  such  as  the  lead  subacetates,  which  are  com- 
pounds containing  the  normal  acetate  and  the  hydroxid  or  oxid  of 
lead;  and  to  salts  such  as  the  so-called  bismuth  subnitrate,  which  is 
a  nitrate,  not  of  bismuth,  but  of  the  univalent  radical  (Bi"/O")/. 

By  double  salts  are  meant  such  as  are  formed  by  the  substitution 
of  different  elements  or  radicals  for  two  or  more  atoms  of  replacea- 
ble hydrogen  of  the  acid,  such  as  ammonio-magnesian  phosphate, 
P04Mg"  (NH4)'. 

Radicals.  —  Many  compounds  contain  groups  of  atoms  which  pass 
from  one  compound  to  another,  and,  in  many  reactions,  behave  like 
elementary  atoms.  Such  groups  are  called  radicals,  or  Compound 
radicals. 

Marsh  gas  has  the  composition  CH4.  By  acting  upon  it  in  suitable 
ways  we  can  cause  the  atom  of  carbon,  accompanied  by  three  of  the 
hydrogen  atoms,  to  pass  into  a  variety  of  other  compounds,  such  as 
(CH3)C1,  (CH3)OH,  (CH3)2O,  C2H3O2  (CH3).  Marsh  gas,  therefore, 
consists  of  the  radical  (CH3)  combined  with  an  atom  of  hydrogen: 
(CH3)'H. 

It  is  especially  among  the  compounds  of  carbon  that  the  existence 


I 


CHEMICAL    COMBINATION  53 


. 


f  radicals  comes  into  prominent  notice.     They,  however,  occur  in 
inorganic  substances  also.     Thus  the  nitric  acid  molecule  consists  of 
e  radical  NO2,  combined  with  the  group  OH. 

Like  the  elements,  the  radicals  possess  different  valences,  depend- 
ing upon  the  number  of  unsatisfied  valences  which  they  contain. 
Thus  the  radical  (CH3)  is  univalent,  because  three  of  the  four  valences 
of  the  carbon  atom  are  satisfied  by  atoms  of  hydrogen,  leaving  one 
ree  valence.  The  radical  (PO)  of  phosphoric  acid  is  trivalent,  be- 
cause two  of  the  five  valences  of  the  phosphorus  atom  are  satisfied  by 
the  two  valences  of  the  bivalent  oxygen  atom,  leaving  three  free 
valences. 

In  notation  the  radicals  are  usually  enclosed  in  brackets  as  above, 
to  indicate  their  nature.  The  names  of  radicals  terminate  in  yl  or  in 
gen;  thus:  (CH3)=  methyl;  ( ON  )=  cyanogen. 

The  terms  radical  and  residue  are  not  synonymous.  In  speaking 
of  acids  their  radicals  are  obtained  by  the  subtraction  of  a  number  of 
hydroxyls  equal  to  the  basicity  of  the  acid.  Thus:  HN03 —  HO  = 
NO2;  H2SO4—  2HO  =  SO2;  H3PO4  —  3HO  =  PO.  The  residue  is 
that  which  remains  after  removal  of  the  basic,  or  replaceable,  hydro- 
gen. Thus:  HNO3  —  H  =  NO3;  H2SO4  —  H2  =  SO4 ;  H3PO4  — H3  = 
PO4.  (See  Electrolysis,  p.  29.)  The  anhydrids  (see  p.  65)  are  de- 
rived from  acids  by  removal  of  water.  Thus :  2HNO3  —  H2O  =  N2Os; 
H2SO4  —  H2O  =  SO3 ;  2H3PO4  —  3H2O  =  P2O5. 

Composition  and  Constitution. — The  characters  of  a  compound 
depend  not  only  upon  the  kind  and  number  of  its  atoms,  but  also 
upon  the  manner  in  which  they  are  attached  to  each  other.  There 
are,  for  instance,  two  substances,  each  having  the  empirical  formula 
C2H4O2,  one  of  which  is  a  strong  acid,  the  other  a  neutral  ester.  As 
the  molecule  of  each  contains  the  same  number  and  kind  of  atoms, 
the  differences  in  their  properties  must  be  due  to  differences  in  the 
manner  in  which  the  atoms  are  linked  together. 

The  composition  of  a  compound  is  the  number  and  kind  of 
atoms  contained  in  its  molecule;  and  is  shown  by  its  empirical 
formula. 

The  constitution  of  a  compound  is  the  number  and  kind  of 
atoms  and  their  relations  to  each  other,  within  its  molecule ;  and 
is  shown  by  its  rational  formula. 

A  rational  formula  is  one  which  partly  or  completely  indicates  the 
constitution  of  the  body.  Rational  formula?  are  either  typical  or 
graphic.  In  the  system1  of  typical  formulae  all  substances  are  con- 
sidered as  being  so  constituted  that  their  rational  formulas  may  be 
referred  to  one  of  three  classes  or  types,  or  to  a  combination  of  two 
of  these  types.  These  three  classes,  being  named  after  the  most 
common  substance  occurring  in  each,  are  expressed  thus: 


54  MANUAL    OF    CHEMISTRY 

The  hydrogen  The  Water  The  ammonia 

type.  type.  type. 

H  H 

H 


H 


I  H  I Q  H  ) 

J  H  /°  H    IN 

H  J 

H^}  i'h 

etc.,  etc.,  H2 

etc., 

it  being  considered  that  the  formula  of  any  substance  of  known  con- 
stitution can  be  indicated  by  substituting  the  proper  element,  or  radi- 
cal, for  one  or  more  of  the  atoms  of  the  type,  thus: 

Cll       (CaHs'Ho          (CaHs)')  'CIO       (802)"\o      (CO)") 

H/  H/°  H   [N        Ca  }  H2}°2          H2    N2 

H  J  H2J 

Hydrochloric     Alcohol.  Ethylamin.  Calcium        Sulfuric  Urea, 

acid.  chlorid.  acid. 

Typical  formulae  are  of  great  service  in  the  classification  of  com- 
pound substances,  as  well  as  to  indicate,  to  a  certain  degree,  their 
nature  and  the  method  of  the  reactions  into  which  they  enter.  Thus 
in  the  ease  of  the  two  substances  mentioned  above,  as  both  having  the 
composition  C2H4O2,  we  find  on  examination  that  one  contains  the 
group  (CHaK,  while  the  other  contains  the  group  (C2HsO)/.  The  dif- 
ference in  their  constitution  at  once  becomes  apparent  in  their  typical 

formulae,  ((CH$}<>  and    (C2H3°^}  O,  indicating  differences  in  their 

properties,  which  we  find  upon  experiment  to  exist.  The  first  sub- 
stance is  neutral  in  reaction  and  possesses  no  acid  properties;  it 

closely  resembles  a  salt  of  an  acid  having  the  formula  ^         JO.  The 


second  substance,  on  the  other  hand,  has  a  strongly  acid  reaction, 
and  markedly  acid  properties,  as  indicated  by  the  oxidized  radical  and 
the  extra -radical  hydrogen.  It  is  capable  of  forming  salts  by  the 
substitution  of  an  atom  of  a  univalent,  basylous  element  for  its  single 

replaceable  atom  of  hydrogen:  Na}  ^' 

Although  typical  formulae  have  been  and  still  are  of  great  service, 
many  cases  arise,  especially  in  treating  of  the  more  complex  organic 
substances,  in  which  they  do  not  sufficiently  indicate  the  relations 
between  the  atoms  which  constitute  the  molecule,  and  thus  fail  to 
convey  a  proper  idea  of  the  nature  of  the  substance.  Considering, 
for  example,  the  ordinary  lactic  acid,  we  find  its  composition  to  be 
C3H6O3,  which,  expressed  typically,  would  be  H  H2}^2'  a  constitu- 
tion supported  by  the  fact  that  the  radical  (CsI^O)"  may  be  obtained 
in  other  compounds,  as  H4(ci2  [  •  This  constitution,  however,  can- 
not be  the  true  one,  because  in  the  first  place,  lactic  acid  is  not  di- 


CHEMICAL    COMBINATION  55 


basic,  but  monobasic;  and  in  the  second  place,  there  is  another  acid, 
called  hydracrylic  acid,  having  an  identical  composition,  yet  differing 
in  its  products  of  decomposition.  These  differences  in  the  properties 
of  the  two  acids  must  be  due  to  a  different  arrangement  of  atoms 
in  their  molecules,  a  view  which  is  supported  by  the  sources  from 
which  they  are  obtained  and  the  nature  of  their  products  of  decom- 
position. 

To  express  the  constitution  of  such  bodies  graphic  formulae  are 
used,  in  which  the  position  of  each  atom  in  relation  to  the  others  is 
set  forth.  The  constitution  of  the  two  lactic  acids  would  be  expressed 
by  graphic  formula  in  this  wa^: 


'H  C/H 


C— H 


TT 


,0-H 


/H  and  P/H 

\0— H  V\H 


/0 

\0-H  C\0 

i 
or,  CH3  CH2OH 

CH.OH  and  CH2 

CO.  OH  CO.  OH 

Ordinary  Hydracrylic 

lactic  acid.  acid. 

Graphic  formulae  are  usually  still  further  abbreviated,  bonds  being 
indicated  by  dots;  thus:  CH3.  CHOH.  COOH,  and  CH2OH.  CH2. 
COOH. 

It  must  be  understood  that  these  graphic  formulae  are  simply  in- 
tended to  show  the  relative  attachments  of  the  atoms,  and  are  in 
nowise  intended  to  convey  the  idea  that  the  molecule  is  spread  out 
upon  a  flat  surface,  with  the  atoms  arranged  as  indicated  in  the  dia- 
gram. 

Great  care  and  much  labor  are  required  in  the  construction  of 
these  graphic  formulae,  the  positions  of  the  atoms  being  determined 
by  a  close  study  of  the  methods  of  formation,  and  of  the  products  of 
decomposition  of  the  substance  under  consideration.  Naturally  in  a 
matter  of  this  nature,  there  is  always  room  for  differences  of  opinion 
—indeed,  the  entire  atomic  theory  is  open  to  question,  as  is  the  theory 
of  gravitation  itself.  But  whatever  may  be  advanced,  two  facts  ca] 
not  be  denied:  first,  that  chemistry  owes  its  advancement  within  the 
past  half -century  to  the  atomic  theory,  which  to-day  is  more  in  con- 
sonance with  observed  facts  than  any  substitute  which  can  be  off 
second,  that  without  the  use  of  graphic  formulae  it  is  impossible  to 


56  MANUAL    OF    CHEMISTRY 

offer  any  adequate  explanation  of  the  reactions  which  we  observe  in 
dealing  with  the  more  complex  organic  substances. 

In  chemistry,  as  in  other  sciences,  a  sharp  distinction  must  always 
be  made  between  facts  and  theories:  the  former,  once  observed,  are 
immutable  additions  to  our  knowledge ;  the  latter  are  of  their  nature 
subject  to  change  with  our  increasing  knowledge  of  facts.  We  have 
every  reason  for  believing,  however,  that  the  supports  upon  which 
the  atomic  theory  rests  are  such  that,  although  it  may  be  modified  in 
its  details,  its  essential  features  will  remain  unaltered. 

Classification  of  the  Elements. — Berzelius  was  the  first  to  divide 
all  the  elements  into  two  great  classes,  to  which  he  gave  the  names 
metals  and  metalloids.  The  metals,  being  such  substances  as  are 
opaque,  possess  what  is  known  as  metallic  luster,  are  good  conductors 
of  heat  and  electricity,  and  are  electro -positive;  the  metalloids,  on 
the  other  hand,  such  as  are  gaseous,  or,  if  solid,  do  not  possess  me- 
tallic luster,  have  a  comparatively  low  power  of  conducting  heat  and 
electricity,  and  are  electro -negative. 

This  division,  based  upon  purely  physical  properties,  which,  in 
many  cases,  are  ill-defined,  has  become  insufficient.  Several  elements 
formerly  classed  under  the  above  rules  with  the  metals,  resemble  the 
metalloids  in  their  chemical  characters  much  more  closely  than  they 
do  any  of  the  metals.  Indeed,  by  the  characters  mentioned  above, 
it  is  impossible  to  draw  any  line  of  demarcation  which  shall  separate 
the  elements  distinctly  into  two  groups. 

The  classification  of  the  elements  should  be  such  that  each  group 
shall  contain  elements  whose  chemical  properties  are  similar  —  the 
physical  properties  being  considered  only  in  so  far  as  they  are  inti- 
mately connected  with  the  chemical.  The  arrangement  of  elements 
into  groups  is  not  equally  easy  in  all  cases.  Some  groups,  as  the 
chlorin  group,  are  sharply  defined,  while  the  members  of  others 
differ  from  each  other  more  widely  in  their  properties.  The  position 
of  most  of  the  more  recently  discovered  elements  is  still  uncertain, 
owing  to  the  imperfect  state  of  our  knowledge  of  their  properties. 

The  method  of  classification  which  we  will  adopt,  and  which 
we  believe  to  be  more  natural  than  any  hitherto  suggested,  is  based 
upon  the  chemical  properties  of  the  oxids  and  upon  the  valence  of  the 
elements.  We  abandon  the  division  into  metals  and  metalloids,  and 
substitute  for  it  a  division  into  four  great  classes,  according  to  the 
nature  of  the  oxids  and  the  existence  or  non-existence  of  oxysalts. 
In  the  first  of  these  classes  hydrogen  and  oxygen  are  placed  to- 
gether, for  the  reason  that,  although  they  differ  from  each  other  in 
many  of  their  properties,  they  together  form  the  basis  of  our  classi- 
fication, and  may,  for  this  and  other  reasons,  be  regarded  as  typical 


, 

elem 


CHEMICAL    COMBINATION  57 


elements.  They  both  play  important  parts  in  the  formation  of  acids, 
and  neither  would  find  a  suitable  place  in  either  of  the  other  classes. 
Our  primary  division  would  then  be  as  follows: 

Class    I. — Typical  elements. 

Class  II. —  Elements  whose  oxids  unite  with  water  to  form 
acids,  never  to  form  bases.  Which  do  not  form  oxysalts. 

This  class  contains  all  the  so-called  metalloids  except  hydrogen 
and  oxygen. 

Class  III. —  Elements  whose  oxids  unite  with  water,  some  to 
form  bases,  others  to  form  acids.  Which  form  oxysalts. 

Class  IV. — Elements  whose  oxids  unite  with  water  to  form 
bases  ;  never  to  form  acids.  Which  form  oxysalts. 

In  this  class  are  included  the  more  strongly  electro-positive  metals. 

Within  the  classes  a  further  subdivision  is  made  into  groups, 
each  group  containing  those  elements  within  the  class  which  have 
equal  valences,  which  form  corresponding  compounds,  and  whose 
chemical  characters  are  otherwise  similar. 

For  the  sake  of  convenience  the  term  metal  is  retained  to  apply 
to  the  members  of  Classes  III  and  IV;  the  term  non-metal  being 
used  for  those  belonging  to  Class  II. 

Class  I.     Typical  Elements. 
GROUP  I.— Hydrogen.  GROUP  II.— Oxygen. 

Class  II.     Acidulous  Elements. 

GROUP      I. — Fluorin,  chlorin,  bromin,  iodin. 

GROUP  II. — Sulfur,  selenium,  tellurium. 

GROUP  III.— Nitrogen,  phosphorus,  arsenic,  antimony. 

GROUP  IV.— Boron. 

GROUP  V. — Carbon,  silicon. 

GROUP  VI. — Vanadium,  niobium,  tantalium. 

GROUP  VII.— Molybdenum,  tungsten,  osmium. 

Class  III.     Amphoteric  Elements. 

GROUP        I.— Gold. 

GROUP      II. — Chromium,  manganese,  iron. 

GROUP    III. — Uranium. 

GROUP     IV. — Lead. 

GROUP      V. — Bismuth. 

GROUP     VI. — Titanium,  germanium,  zirconium,  tin. 

GROUP  VII. — Palladium,  platinum. 

GROUP  VIII. — Rhodium,  ruthenium,  iridium. 


58 


MANUAL    OF    CHEMISTRY 


Class  IV.     Basylous  Elements. 

GROUP       I. — Lithium,    sodium,    potassium,    rubidium,    cesium, 

silver. 
Thallium. 

Calcium,  strontium,  barium. 
Magnesium,  zinc,  cadmium. 

Beryllium,  aluminium,  scandium,  gallium,  indium. 
Nickel,  cobalt. 
Copper,  mercury. 

Cerium,  neodym,  praseodym,  erbium. 
Yttrium,  lanthanum,  samarium,  ytterbium. 
Thorium. 


GROUP 
GROUP 
GROUP 
GROUP 
GROUP 
GROUP  VII. 
GROUP  VIII. 
GROUP  IX. 
GROUP  X. 


II.- 
III.- 
IV.- 

V.- 
VI.- 


INORGANIC   CHEMISTRY. 


CLASS   I.— TYPICAL  ELEMENTS. 
HYDROGEN  —  OXYGEN. 

ALTHOUGH,  in  a  strict  sense,  hydrogen  is  regarded  by  most 
chemists  as  the  one  and  only  type -element  —  that  whose  atom  is 
the  unit  of  atomic  and  molecular  weights  —  the  important  part 
which  oxygen  plays  in  the  formation  of  those  compounds  whose 
nature  forms  the  basis  of  our  classification,  its  acid -forming  power 
in  organic  compounds,  and  the  differences  existing  between  its  prop- 
erties and  those  of  the  elements  of  the  sulfur  group,  with  which  it  is 
usually  classed,  warrant  us  in  separating  it  from  the  other  elements 
and  elevating  it  to  the  position  it  here  occupies. 

HYDROGEN. 

Symbol=~H. —  Univalent  —  Atomic  weight  =  1 — Molecular  weight= 
2—Sp.  gr.=Q.Q6926A*—One  litre  weighs  0.0896  gram\— 100  cubic 
inches  iveigh  2.1496  grainsl — 1  gram  measures  11.16  litres^ — 1  grain 
measures  46.73  cubic  inches^ — Name  derived  from  v&<*>p=water,  and 
yewd(D=l  produce — Discovered  by  Cavendish  in  1766. 

Occurrence. — Occurs  free  in  volcanic  gases,  in  fire-damp,  occluded 
in  meteorites,  in  the  gases  exhaled  from  the  lungs,  and  in  those  of 
the  stomach  and  intestine.  In  combination  in  water,  hydrogen 
sulfid,  ammoniacal  compounds,  and  in  many  organic  substances. 

Preparation.— (1)  By  electrolysis  of  water,  H  is  given  off  at 
the  negative  pole.  Utilized  when  pure  H  is  required. 

(2)  By  the  dissociation  of  water  at  very  high  temperatures. 

(3)  By  the  decomposition  of  water  by  certain  metals.     The  alkali 
metals  decompose  water  at  the  ordinary  temperature: 

Na2  +  2H2O  2NaHO  +  H2 

Sodium.  Water.  Sodium  hydroxid.  Hydrogen. 

Some  other  metals,  such  as  iron  and  copper,  effect  the  decompo- 
sition only  at  high  temperatures: 

3Fe2          H-  8H2O  2Fe3O4  +  8H2 

Iron.  Water.  Triferrie  tetroxid.  Hydrogen. 

*Air  =  1.  When  the  sp.  gr.  is  referred  to  H  =  1,  A  is  replaced  by  H. 
tAt  0°  C.  and  760  mm.  barometric  pressure. 
tAt  60°  F.  and  30  inches  bar.  pressure. 

(59) 


60 


MANUAL    OF    CHEMISTRY 


(4)  By  decomposition  of  water,  passed  over  red-hot  coke: 


C 

Carbon. 


2H20 
Water. 


or  at  a  higher  temperature: 


C 

Carbon. 


H20 

Water. 


C02 

Carbon  dioxid. 


CO  + 

Carbon  monoxid. 


2H2 

Hydrogen. 


H2 

Hydrogen. 


(5)  By  decomposition  of  mineral  acids,  in  the  presence  of  water, 
by  zinc  and  certain  other  metals : 


Zn 

Zinc. 


-f       H2S04 
Sulfuric  acid. 


Water. 


=      ZnSO4 
Zinc  sulfate. 


H2 
Hydrogen. 


Water. 


The  water  serves  to  dissolve  the  zinc  sulfate.  Chemically  pure 
zinc,  or  zinc  whose  surface  has  been  covered  with  an  alloy  of  zinc 
and  mercury,  does  not  decompose  the  acid  unless  it  forms  part  of 
a  galvanic  battery  whose  circuit  is  closed.  The  zincs  of  galvanic 
batteries  are  therefore  covered  with  the  alloy  mentioned — are  amal- 
gamated ' — to  prevent  waste  of  zinc  and  acid. 

This  is  the  method  usually  resorted 
to  for  obtaining  H.  The  gas  so  ob- 
tained, is,  however,  contaminated  with 
small  quantities  of  other  gases,  hydro- 
gen phosphid,  sulfid  and  arsenid. 

Hydrogen,  carbon  di- 
oxid, hydrogen  sulfid,  and 
other  gases  produced  by 
the  action  of  a  liquid  upon 
a  solid  at  ordinary  temper- 
atures, are  best  prepared  in 
one  of  the  forms  of  appa- 
ratus shown  in  Figs.  19, 
19  and  20. 

The  solid  material  is 
placed  in  the  larger  bottle 
(Fig.  18),  or,  over  a  layer  of  broken  glass  about  five  centimetres 
thick,  in  the  bottle  a  (Fig.  19).  The  liquid  reagent  is  from  time  to 
time  introduced  by  the  funnel  tube,  Fig.  18;  or  the  bottle  &,  Fig.  19, 
is  filled  with  it.  The  wash -bottles  are  partially  filled  with  water  to 
arrest  any  liquid  or  solid  impurity.  The  apparatus,  Figs.  19  and  20, 
have  the  advantage  of  being  always  ready  for  use.  When  the 
stopcock  is  open  the  gas  escapes.  When  it  is  closed  the  internal 
pressure  depresses  the  level  of  the  liquid  in  a  into  the  layer  of 
broken  glass,  and  the  action  is  arrested.  Kipp's  apparatus,  Fig. 
20,  is  another  convenient  form  of  constant  apparatus.  The  solid 
reagent  is  placed  in  the  central  bulb. 


FIG.  18. 


HYDROGEN 


61 


(6)   By  heating  together  a  mixture  of  zinc  dust  and  dry  -slacked 


Zn 

Zinc. 


+          CaH2O2 

Calcium  hydroxid. 


ZnO 
Zinc  oxid. 


CaO          -f          H2 
Calcic  monoxid.         Hydrogen. 


FIG.  19. 


Properties. — Physical. — Hydrogen  is  a  colorless,  odorless,  taste- 
gas;    14.47  times  lighter  than  air,  being  the  lightest  substance 
own.     The    weight  of  a 
Ltre,  0.0896  gram,  is  called  <*=*     b 

crith  ( KptOrj = barleycorn ) . 
From  this  the  weight  of  a 
litre  of  any  gas  may  be 
calculated  by  multiplying 
half  its  molecular  weight 
by  .0896.  It  is  almost  in- 
soluble in  water  and  alco-  fjj 
hoi.  It  conducts  heat  and  i 
electricity  better  than  any  JJj 
other  gas.  In  obedience 
to  the  law:  The  dif fusi- 
bility of  two  gases  varies  inversely  as  the  square  roots  of  their 
densities,  it  is  the  most  rapidly  diffusible  of  gases.  The  rapidity 
with  which  this  diffusion  takes  place  renders  the  use  of  hydrogen, 
which  has  been  kept  for  even  a  short  time  in  gas-bags  or  gasometers, 
dangerous.  It  has  been  liquefied  by  a  temperature  of 
-240°  (—400°  F.)  under  a  pressure  of  13.3  atin. 
The  liquid  is  clear  and  colorless,  boils  at  —  238° 
(396.4°  F.),  and  has  a  sp.  gr.  of  0.068. 

Certain  metals  have  the  power  of  absorbing  large 
quantities  of  hydrogen,  which  is  then  said  to  be 
occluded.  Palladium  absorbs  980  vol- 
umes of  the  gas  when  used  as  the  neg- 
ative electrode  in  the  electrolysis  of 
water.  The  occluded  gas  is  driven  off 
by  the  application  of  heat,  and  possesses 
great  chemical  activity,  similar  to  that 
which  it  has  when  in  the  nascent  state. 
This  latter  quality,  and  the  fact  that 
heat  is  liberated  during  the  occlusion, 
would  seem  to  indicate  that  the  gas  is 
contained  in  the  metal,  not  in  a  mere 
physical  state  of  condensation,  but  in 
chemical  combination. 
Chemical.—  Hydrogen  exhibits  no  great  tendency  to  combine  with 
other  elements  at  ordinary  temperatures.  It  combines  explosively, 


FIG.  20. 


62  MANUAL    OF    CHEMISTRY 

however,  with  chlorin  under  the  influence  of  sunlight,  and  with 
fluorin  even  in  the  dark.  It  does  not  support  combustion,  but,  when 
ignited,  burns  with  a  pale  blue  and  very  hot  flame;  the  result  of  the 
combination  being  water.  Mixtures  of  hydrogen  and  oxygen  ex- 
plode violently  on  the  approach  of  flame,  or  by  the  passage  of  the 
electric  spark,  the  explosion  being  caused  by  the  sudden  expansion 
of  the  vapor  of  water  formed,  under  the  influence  of  the  heat  of  the 
reaction.  Hydrogen  also  unites  with  oxygen  when  brought  in  con- 
tact with  spongy  platinum.  Many  compounds  containing  oxygen 
give  up  that  element  when  heated  in  an  atmosphere  of  hydrogen: 

CuO  4-  H2  Cu  +  H2O 

Cupric  oxid.  Hydrogen.  Copper.  Water. 

The  removal  of  oxygen  from  a  compound  is  called  a  reduction 
or  deoxidation.  In  a  broader  sense  the  term  reduction  is  applied  to 
any  diminution  in  the  relative  quantity  of  the  electro-negative 
factor  in  a  compound.  Thus  mercuric  chlorid,  HgCl2  (Hg  200:  Cl 
71)  is  reduced  to  mercurous  chlorid,  Hg2Cl2  (Hg  200:  Cl  35.5). 

At  the  instant  that  H  is  liberated  from  its  compounds  it  has  a 
deoxidizing  power  similar  to  that  which  ordinary  H  possesses  only 
at  elevated  temperatures,  and  its  tendency  to  combine  with  other 
elements  is  greater  than  under  other  conditions.  The  greater 
energy  of  H,  and  of  other  elements  as  well,  in  this  nascent  state, 
may  be  thus  explained.  Free  H  exists  in  the  form  of  molecules, 
each  one  of  which  is  composed  of  two  atoms,  but  at  the  instant  of 
its  liberation  from  a  compound,  it  is  in  the  form  of  individual  atoms, 
and  that  portion  of  force  required  to  split  up  the  molecule  into 
atoms,  necessary  when  free  H  enters  into  reaction,  is  not  required 
when  the  gas  is  in  the  nascent  state. 

In  its  physical  and  chemical  properties,  this  element  more  closely 
resembles  those  usually  ranked  as  metals  than  it  does  those  forming 
the  class  of  non-metals,  among  which  it  is  usually  placed.  Its  con- 
ducting power,  as  well  as  its  relation  to  the  acids,  which  may  be 
considered  as  salts  of  H,  tend  to  separate  it  from  the  non-metals. 

Analytical  Characters. — (1)  Burns  with  a  faintly  blue  flame, 
which  deposits  water  on  a  cold  surface  brought  over  it;  (2)  Mixed 
with  oxygen,  explodes  on  contact  with  flame,  producing  water. 

HELIUM. 

A  gaseous  element  existing  in  certain  minerals  and  in  many 
spring  waters.  Its  atomic  weight  is  3.97.  Its  spectrum  consists 
of  a  single  bright  yellow  line  coincident  with  Da  of  the  solar  spec- 
trum. It  has  been  liquefied. 


OXYGEN  63 


OXYGEN. 


Symbol  =  O  —  Bivalent  — Atomic  weight  =  15.87;  molecular  weight 
=  31.74  —  8p.  gr.=  1.10563  A  (calculated  =  1.1088) ;  15.95  H;  sp. 
gr.  of  liquid:=0.9787 —  One  litre  weighs  1.422  grams;  100  cubic  inches 
weigh  34.27  grains  —  Name  derived  from  &$vf=arid,  and  ycwao>=  / 
produce  —  Discovered  by  Mayow  in  1674;  rediscovered  by  Priestley 
in  1774. 


Occurrence. —  Oxygen  is  the  most  abundant  of  the  elements.  It 
exists  free  in  atmospheric  air;  in  combination  in  a  great  number 
of  substances,  mineral,  vegetable,  and  animal. 

Preparation. —  (1)   By  heating  certain  oxids: 


2HgO  =  2Hg  +  02 

Mercuric  oxid.  Mercury.  Oxygen. 


This  was  the  method  used  by  Priestley.  100  grams  of  mercuric 
oxid  produce  5.16  litres  of  oxygen: 

3MnO2  Mn3O4  +  O2 

Manganese  dioxid.          Trimanganic  tetroxid.  Oxygen. 

The  black  oxid  of  manganese  is  heated  to  redness  in  an  iron  or 
clay  retort  (Scheele,  1775);  and  100  grams  yield  8.51  litres  of 
oxygen. 

(2)  By  the  electrolysis    of  water,  acidulated  with  sulfuric  acid, 
O  is  given  off  at  the  positive  pole. 

(3)  By  the  action  of  sulfuric  acid  upon  certain  compounds  rich 
in  O:  manganese  dioxid,  potassium  dichromate,  and  plumbic  peroxid: 

2Mn02         -f        2H2S04        =        2MnSO4        +       2H2O      +        O2 
Manganese  dioxid.          Sulfuric  acid.          Manganous  sulfate.  Water.  Oxygen. 

100  grams  of  manganese  dioxid  produce  12.83  litres  of  O. 

(4.)  By  decomposing  H2SO4  at  a  red  heat,  2H2SO4  =  2SO2  + 
2H2O  +  02. 

(5)  By  the  decomposition  by  heat  of  certain  salts  rich  in  O: 
alkaline  permanganates,  nitrates,  and  chlorates. 

The  best  method,  and  that  usually  adopted,  is  by  heating  a 
mixture  of  potassium  chlorate  and  manganese  dioxid  in  equal  parts, 
moderately  at  first  and  more  strongly  toward  the  end  of  the  reaction. 
The  chlorate  gives  up  all  its  O  (27.33  litres  from  100  grams  of  the 
salt),  according  to  the  equation: 

2KC103  2KC1  +  302 

Potassium  chlorate.  Potassium  chlorid.  Oxygen. 

At  the  end  of  the  operation  the  manganese  dioxid  remains, 
apparently  unchanged. 

A  small  quantity  of  free  chlorin  usually  exists  in  the  gas  pro- 


water  for  24  hours. 

When  heat  is  required  for  the  generation  of  gases  the  operation  is 
conducted  in  retorts  of  glass  or  metal,  or  in  the  apparatus  shown  in 
Fig.  21.  If  the  gas  be  collected  over  water  the  disengagement  tube 


,FlG.  21. 

must  be  withdrawn  from  the  water,  before  the  source  or  heat  is 
removed.  Neglect  of  this  precaution  will  cause  an  explosion,  by  the 
the  entrance  of  water  into  the  hot  flask,  by  the  contraction  of  the 
gas  contained  in  it,  on  partial  cooling. 

(6)  By  the  action  of  water  upon  sodium  peroxid  : 


2Na202 

Sodium  peroxid. 


2H20 

Water. 


4NaHO 

Sodium  hydroxid. 


02 

Oxygen. 


(7)  By  the    mutual    decomposition    of   potassium   permanganate 
and  hydrogen  peroxid,  in  the  presence  of  sulfuric  acid: 


H202 

Hydrogen  peroxid. 


K2Mn2O8          + 
Potassium  permanganate. 


3H2SO4 

Sulfuric  acid. 


2MnS04 
Manganous  sulfate. 


4H20 

Water. 


=       K2S04 
Potassium  sulfate. 

3O2 
Oxygen. 


One  kilo  H2O2  (3  per  cent)  and  500  cc.  dilute  H2SO4  (1:5)  are 
placed  in  the  generating  flask  and  56  grams  K^Mi^Og,  dissolved  in 
HoO,  are  gradually  added.  With  these  quantities  20  litres  O  are 
obtained. 

(8)  By  the  action  of  dilute  hydrochloric  acid  upon  a  mixture  of  2 


im  peroxia,  l  part  manganese  dioxid,  and  1  part  plaster  of 
*aris,  compressed  into  cubes  about  1%  cent,  square. 

Methods  6,  7,  and  8  have  the  advantage  that  heat  is  not  required, 
id  the  forms  of  apparatus,  Figs.  18,  19,  and  20,  may  be  used. 

Properties.— Physical.— Oxygen  is  a  colorless,  odorless,  tasteless 
jas,  soluble  in  water  in  the  proportion  of  7.08  cc.  in  1  litre  of  water 
it  14.8°  (58.6°  F.),  somewhat  more  soluble  in  absolute  alcohol.  It 
iquefles  at— 140°  (—220°  F.)  under  a  pressure  of  300  atmospheres, 
liquid  oxygen  boils  at— 187.4°  (—294.5°  F.)  at  the  ordinary  pres- 

re.      The  sp.  gr.  of  liquid  oxygen  is  0.9787. 

Chemical.—  Oxygen  is  characterized,  chemically,  by  the  strong 
tendency  which  it  exhibits  to  enter  into  combination  with  other  ele- 
ments. It  forms  binary  compounds  with  all  elements  except  fluorin 
and  bromin.  With  most  elements  it  unites  directly,  especially  at 
elevated  temperatures.  In  many  instances  this  union  is  attended  by 
the  appearance  of  light,  and  always  by  the  extrication  of  heat.  The 
luminous  union  of  O  with  another  element  constitutes  the  familiar 
phenomenon  of  combustion,  and  is  the  principal  source  from  which 
we  obtain  so-called  artificial  heat  and  light.  A  body  is  said  to  be 
combustible  when  it  is  capable  of  so  energetically  combining  with 
the  oxygen  of  the  air  as  to  liberate  light  as  well  as  heat.  Gases  are 
said  to  be  supporters  of  combustion,  when  combustible  substances 
will  unite  with  them,  or  with  some  of  their  constituents,  the  union 
being  attended  with  the  appearance  of  heat  and  light.  The  distinc- 
tion between  combustible  substances  and  supporters  of  combustion 
is,  however,  one  of  mere  convenience.  The  action  taking  place  be- 
tween the  two  substances,  one  is  as  much  a  party  to  it  as  the  other. 
A  jet  of  air  burns  in  an  atmosphere  of  coal-gas  as  readily  as  a  jet  of 
coal-gas  burns  in  air. 

An  oxidation  is  a  chemical  action  in  which  oxygen  combines 
with  an  element  or  a  compound.  The  burning  of  coal:  C+O=CO 
or  C-\-O2—CO2 ;  and  the  formation  of  acetic  acid  from  alcohol: 
C2H6O+O2=C2H4O2+H2O,  are  oxidations.  In  a  broader  sense  the 
word  "oxidation"  is  sometimes  used  as  the  opposite  to  "reduction" 
(p.  62)  to  apply  to  any  increase  in  the  relative  quantity  of  the  electro- 
negative element  in  a  compound.  Thus  the  conversion  of  FeCb  (Fe 
112:C1  142)  into  Fe2Cl6  (Fe  112:01  213)  may  be  referred  to  as  an 
oxidation,  although  it  is,  more  properly,  a  chlorination. 

The  compounds  of  oxygen— the  oxids — are  divisible  into  three 
groups : 

1.  Anhydrids.— Oxids  capable  of  combining  with  water  to  form 
acids.  Thus  sulfuric  anhydrid,  S03,  unites  with  water  to  form 
sulfuric  acid,  HoSO*. 

The  term  anhydrid  is  not  limited  in  application  to  Unary  com- 


66  MANUAL    OF    CHEMISTRY 

pounds,  but  applies  to  any  substance  capable  of  combining  with  water 
to  form  an  acid.  Thus  the  compound  C4HeO3  is  known  as  acetic 
anhydrid,  because  it  combines  with  water  to  form  acetic  acid:  CiHeOa 
-j-H2O=2C2H4O2.  (See  compounds  of  arsenic  and  sulfur.) 

2.  Basic  oxids  are  such  as  combine  with  water  to  form  bases. 
Thus  calcium  oxid,  CaO,  unites  with  water  to  form  calcium  hydroxid, 
CaH202. 

3.  Saline,  neutral  or  indifferent  oxids  are  such  as  are  neither 
acid  nor  basic  in  character.     In  some  instances  they  are  essentially 
neutral,  as  in  the  case  of  the  protoxid  of  hydrogen,  or  water.     In 
other  cases  they  are  formed  by  the  union  of  two  other  oxids,  one 
basic,  the  other  acid  in  quality,  such  as  the  red  oxid  of  lead,  Pb304, 
formed  by  the  union  of  a  molecule  of  the  acidulous  peroxid,  PbO2, 
with  two  of  the  basic  protoxid,  PbO.     It  is  to  oxids  of  this  character 
that  the  term  "saline"  properly  applies. 

The  process  of  respiration  is  very  similar  to  combustion,  and  as 
oxygen  gas  is  the  best  supporter  of  combustion,  so,  in  the  diluted 
form  in  which  it  exists  in  atmospheric  air,  it  is  not  only  the  best,  but 
the  only  supporter  of  animal  respiration.  (See  Carbon  dioxid.) 

Analytical  Characters. —  1.  A  glowing  match -stick  bursts  into 
flame  in  free  oxygen.  2.  Free  O,  when  mixed  with  nitrogen  dioxid, 
produces  a  brown  gas. 

Ozone. — Allotropic  oxygen. — Afr  through  which  discharges  of 
static  electricity  have  been  passed,  and  oxygen  obtained  by  the  de- 
composition of  water  (if  electrodes  of  gold  or  platinum  be  used), 
have  a  peculiar  odor,  somewhat  resembling  that  of  sulfur,  which  is 
due  to  the  conversion  of  a  part  of  the  oxygen  into  ozone. 

Ozone  is  produced:  1.  By  the  decomposition  of  water  by  the  bat- 
tery. 2.  By  the  slow  oxidation  of  phosphorus  in  damp  air.  3.  By 
the  action  of  concentrated  sulfuric  acid  upon  barium  dioxid.  4.  By 
the  passage  of  silent  electric  discharges  through  air  or  oxygen. 

In  the  preparation  of  ozonized  oxygen  the  best  results  are 
obtained  by  passing  a  slow  current  of  oxygen  through  an  apparatus 
made  entirely  of  glass  and  platinum,  cooled  by  a  current  of  cold 
water,  and  traversed  by  the  invisible  discharge  of  an  induction  coil. 

Pure,  liquid  ozone  has  been  obtained  by  subjecting  ozonized 
oxygen  to  the  temperature  of  liquid  oxygen  at  the  atmospheric 
pressure.  It  is  a  dark  blue  liquid,  almost  opaque  in  layers  2  mm. 
thick,  which  is  not  decomposed  at  the  ordinary  temperature,  but 
converted  into  a  bluish  gas.  It  boils  at  —119°  (— 182. 2°F.). 

When  oxygen  is  ozonized  it  contracts  slightly  in  volume,  and 
when  the  ozone  is  removed  from  ozonized  oxygen  by  mercury  or 
potassium  iodid  the  volume  of  the  gas  is  not  diminished.  These 
facts,  and  the  great  chemical  activity  of  ozone,  have  led  chemists 


WATER  57 

to  regard  it  as  condensed  oxygen;  the  molecule  of  ozone  being 
represented  thus  (OOO),  while  that  of  ordinary  oxygen  is  (00). 

Ozone  is  very  sparingly  soluble  in  water,  more  soluble  in  the 
pressure  of  hypophosphites,  insoluble  in  solutions  of  acids  and 
alkalies.  In  the  presence  of  moisture  it  is  slowly  converted  into 
oxygen  at  100°  (212°  F.),  a  change  which  takes  place  rapidly  and 
completely  at  237°  (459°  F.)  It  is  a  powerful  oxidant;  it  decom- 
poses solutions  of  potassium  iodid  with  formation  of  potassium 
hydroxid,  and  liberation  of  iodin;  it  oxidizes  all  metals  except  gold 
and  platinum,  in  the  presence  of  moisture;  it  decolorizes  indigo  and 
other  organic  pigments,  and  acts  rapidly  upon  rubber,  cork,  and  other 
organic  substances. 

Analytical  Characters. — 1.  Neutral  litmus  paper,  impregnated 
with  solution  of  potassium  iodid,  is  turned  blue  when  exposed  to  air 
containing  ozone.  The  same  litmus  paper  without  iodid  is  not  affected. 
2.  Manganous  sulfate  solution  is  turned  brown  by  ozone.  3.  Solu- 
tions of  thallous  salts  are  colored  yellow  or  brown  by  ozone.  4. 
Paper  impregnated  with  fresh  tincture  of  natural  (unpurified)  guai- 
acum  is  colored  blue  by  ozone.  5.  Paper  impregnated  with  solution 
of  manganous  sulfate,  or  lead  hydroxid,  or  palladium  chlorid  is  col- 
ored dark  brown  or  black  by  ozone.  6.  Metallic  silver  is  blackened 
by  ozone. 

When  inhaled,  air  containing  0.07  gram  of  ozone  per  litre  causes 
intense  coryza  and  haemoptysis.  It  is  probable  that  ozone  is  by  no 
means  as  constant  a  constituent  of  the  atmosphere  as  was  formerly 
supposed.  (See  Hydrogen  dioxid.) 


COMPOUNDS  OF  HYDROGEN  AND  OXYGEN. 

Two  are  known—hydrogen  oxid  or  water,  H2O ;  hydrogen  peroxid 
or  oxygenated  water,  H2O2. 

WATER. 

H2O— Molecular  weight=lS  Sp.  gr.=l—  Vapor  density =0.6218  A; 
calculated=0.6234: — Composition  discovered  by  Priestley  in  1780 — 1  cc. 
weighs  1  gm.  at  4°  and  0.999  gm.  at  16°— 1  cubic  inch  weighs  252.6 
grains  at  60°  F. 

Occurrence. — In  unorganized  nature  IbO  exists  in  the  gaseous 
form  in  atmospheric  air  and  in  volcanic  gases;  in  the  liquid  form 
very  abundantly;  and  as  a  solid  in  snow,  ice,  and  hail. 

As  water  of  crystallization  it  exists  in  definite  proportions  in  cer- 
tain crystals,  to  the  maintenance  of  whose  shape  it  is  necessary. 


68  MANUAL    OF    CHEMISTRY 


In  the  organized  world  EbO  forms  a  constituent  part  of  every 
tissue  and  fluid. 

Formation.  —  Water  is  formed:  1.  By  union,  brought  about  by 
elevation  of  temperature,  of  one  vol.  O  with  two  vols.  H. 

2.  By  burning  H,  or  substances  containing  it,  in  air  or  in  0. 

3.  By  heating  organic  substances  containing  H  to  redness  with 
cupric  oxid,  or  with  other  substances  capable  of  yielding  O.     This 
method  of  formation  is  utilized  to  determine  the  amount  of  H  con- 
tained in  organic  substances. 

4.  When  an  acid  and  a  hydroxid  react  upon  each  other  to  form  a 
salt: 

H2SO4          +          2KHO  K2SO4          +          2H2O 

Sulfuric  acid.  Potassium  hydroxid.  Potassium  sulfate.  Water. 

5.  When  a  metallic  oxid  is  reduced  by  hydrogen: 

CuO        +        H2  Cu        +        H20 

Cupric  oxid.  Hydrogen.  Copper.  Water. 

6.  In  the  reduction  and  oxidation  of  many  organic  substances. 
Pure  EbO  is  not  found  in  nature.      When  required  free    from 

ordinary  impurities  it  is  separated  from  suspended  matters  by  filtra- 
tion, and  from  dissolved  substances  by  distillation. 

Properties.  —  Physical.  —  With  a  barometric  pressure  of  760  mm. 
H2O  is  solid  below  0°  (32°  F.)  ;  liquid  between  0°  (32°  F.)  and  100° 
(212°  F.)  ;  and  gaseous  above  100°  (212°  F.)  .  When  H2O  is  enclosed 
in  capillary  tubes,  or  is  at  complete  rest,  it  may  be  cooled  to  —  15° 
(5°  F.)  without  solidifying.  If,  while  at  this  temperature,  it  be 
agitated,  it  solidifies  instantly,  and  the  temperature  suddenly  rises  to 
0°  (32°  F.).  The  melting-point  of  ice  is  lowered  0.0075°  (0.0135° 
F.)  for  each  additional  atmosphere  of  pressure. 

The  boiling-point  is  subject  to  greater  variations  than  the  freezing- 
point.  It  is  the  lower  as  the  pressure  is  diminished,  and  the  higher  as 
it  is  increased.  Advantage  is  taken  of  the  reduced  boiling-point  of 
solutions  in  vacuo  for  the  separation  of  substances,  such  as  cane 
sugar,  which  are  injured  at  the  temperature  of  boiling  H2O.  On  the 
other  hand,  the  increased  temperature  that  may  be  imparted  to  liquid 
EbO  under  pressure  is  utilized  in  many  processes  in  the  laboratory  and 
in  the  arts,  for  effecting  solutions  and  chemical  actions  which  do  not 
take  place  at  lower  temperatures.  The  boiling-point  of  H^O  holding 
solid  matter  in  solution  is  higher  than  that  of  pure  H2O,  the  degree 
of  increase  depending  upon  the  amount  and  nature  of  the  substance 
dissolved.  On  the  other  hand,  mixtures  of  H2O  with  liquids  of  lower 
boiling-point  boil  at  temperatures  less  than  100°  (212°  F.)  .  Although 
the  conversion  of  water  into  water  -vapor  takes  place  most  activelv  at 
100°  (212°  F.),  water  and  ice  evaporate  at  all  temperatures. 


WATER  69 

Water  is  the  best  solvent  we  have,  and  acts  in  some  instances  as 
simple  solvent,  in  others  as  a  chemical  solvent. 

Vapor  of  water  is  colorless,  transparent,  and  invisible.  Sp.  gr. 
.6234  A  or  9  H.  A  litre  of  vapor  of  water  weighs  0.8064.  The 
itent  heat  of  vaporization  of  water  is  536.5;  that  is,  as  much  heat 

required  to  vaporize  1  kilo,  of  water  at  100°  as  would  suffice  to 
lise  536.5  kilos,  of  water  1°  in  temperature.     In  passing  from  the 
iquid  to  the  gaseous  state,  water  expands  1,696  times  in  volume. 

Chemical. — Water  may  be  shown  to  consist  of  1  vol.  O  and  2 
rols.  H,  or  8  by  weight  of  O  and   1    by  weight   of   H,   either  by 
talysis  or  synthesis. 

Analysis    is   the  reducing  of  a  compound  to   its  constituent 

ts  or  elements. 

Synthesis  is  the  formation  of  a  compound  from  its  elements. 
A  partial  synthesis  is  one  in  which  a  complex  compound  is  produced 
from  a  simpler  one,  but  not  from  the  elements. 

Water  may  be  resolved  into  its  constituent  gases:  1.  By  elec- 
trolysis of  acidulated  water;  H  being  given  off  at  the  negative  and 
O  at  the  positive  pole.  2.  By  passing  vapor  of  H2O  through  a 
platinum  tube  heated  to  whiteness,  or  through  a  porcelain  tube 
heated  to  about  1,100°.  The  decomposition  of  a  compound  gas  or 
vapor  by  elevation  of  temperature  is  called  dissociation.  3.  By  the 
action  of  the  alkali  metals.  Hydrogen  is  given  off,  and  the  metallic 
hydroxid  remains  in  solution  in  an  excess  of  H^O.  4.  By  passing 
vapor  of  H2O  over  red-hot  iron.  Oxid  of  iron  remains  and  H  is 
given  off. 

Water  combines  with  oxids  to  form  new  compounds,  some  of 
which  are  acids  and  others  bases,  known  as  hydroxids. 

A  hydroxid  is  a  compound  formed  by  the  replacement  of  half 
of  the  hydrogen  of  water  by  another  element  or  by  a  radical. 

A  hydrate  is  a  compound  containing  chemically  combined 
water.  The  act  of  union  of  a  substance  with  water  is  referred  to  as 
hydration. 

The  hydroxids  of  the  electro -negative  elements  and  radicals  are 
acids  ;  most  of  those  of  the  electro -positive  elements  and  radicals 
are  basic  hydroxids. 

Certain  substances,  in  crystallizing,  combine  with  a  definite  pro- 
portion of  water,  which  is  known  as  water  of  crystallization,  and 
whose  presence,  although  necessary  to  the  maintenance  of  certain 
physical  characters,  such  as  color  and  crystalline  form,  does  not 
modify  their  chemical  reactions.  In  many  instances  a  portion  of  the 
water  of  crystallization  may  be  driven  off  at  a  comparatively  low 
temperature,  while  a  higher  temperature  is  required  to  expel  the 
remainder.  This  latter  is  known  as  water  of  constitution. 


70  MANUAL    OF    CHEMISTRY 

The  symbol  Aq  (Latin,  aqua)  is  frequently  used  to  designate  the 
water  of  crystallization,  the  water  of  constitution  being  indicated  by 
H^O.  Thus  MgSOi,  EbO+GAq  represents  magnesium  sulfate  with 
one  molecule  of  water  of  constitution  and  six  molecules  of  water  of 
crystallization.  We  consider  it  preferable,  however,  as  the  distinc- 
tion between  water  of  crystallization  and  water  of  constitution  in 
many  salts  is  only  one  of  degree  and  not  of  kind,  to  use  the  symbol 
Aq  to  designate  the  sum  of  the  two;  thus,  MgSO4+7Aq. 

Water  decomposes  the  chlorids  of  the  second  class  of  elements 
(those  of  carbon  only  at  high  temperatures  and  under  pressure). 
Thus  phosphorous  trichlorid  forms  phosphorous  and  hydrochloric 
acids  :  PC13  +  3H2O  =  H3P03  +  3HC1.  A  decomposition  attended 
with  absorption  of  water  is  called  hydrolysis. 

Natural  Waters. — Natural  waters  which  appear  to  the  senses  to 
be  fit  for  drinking  are  called  potable  waters,  in  contradistinction 
to  such  as  are,  from  their  taste  and  appearance,  obviously  unfit  for 
that  use. 

Potable  waters  may  be  classified,  according  to  their  origin,  into 
four  groups  : 

Meteoric  waters :  rain  water  and  melted  snow.  These  are  the 
purest  natural  waters  if  uncontaminated  ;  they  contain  very  small 
quantities  of  solids,  and  are  highly  aerated.  Rain  water  falling 
during  the  first  part  of  a  shower  is  less  pure  than  that  which  falls 
subsequently.  In  districts  where  notable  quantities  of  coal  which 
contains  sulfur  are  burnt,  rain  water  contains  more  sulfates,  ammo- 
niacal  salts,  nitrates  and  nitrites  than  elsewhere. 

Surface  waters:  the  waters  of  rivers,  lakes  and  ponds.  These 
are  mixtures,  in  varying  proportions,  of  rain  water,  spring  water 
and  the  drainage  of  the  surrounding  land.  They  vary  greatly  in 
natural  purity,  and  are  frequently  contaminated  by  sewage  and 
other  refuse. 

Ground  waters :  water  which  permeates  the  superficial  stratum 
above  the  uppermost  impermeable  rock.  This  is  the  water  obtained 
in  surface  wells  and  in  driven  wells.  Its  quality  depends  upon  what 
is  in  and  on  the  stratum  in  which  the  well  is  dug;  a  driven  well  in  a 
sandy  stratum  remote  from  habitations  yields  an  excellent  water, 
while  the  water  of  a  well  near  a  privy  vault  or  a  defective  sewer  is 
more  or  less  diluted  sewage.  In  limestone  districts  ground  water  is 
hard. 

Deep  waters :  spring  waters  and  those  of  artesian  wells. 

Spring  water  is  rain  water  which,  having  percolated  through  a 
portion  of  the  earth's  crust  (in  which  it  may  also  have  been  subjected 
to  pressure),  has  become  charged  with  solid  and  gaseous  matter, 
varying  in  kind  and  quantity  according  to  the  nature  of  the  strata 


WATER  71 


rough  which  it  has  percolated,  the  duration  of  contact,  and  the 
pressure  to  which  it  was  subject  during  such  contact. 

Spring  waters  from  igneous  rocks  and  from  the  older  sedimentary 
'ormations  are  fresh  and  sweet,  and  any  spring  water  may  be  consid- 

d  such  whose  temperature  is  less  than  20°  (68°  F.),  and  which 

s  not  contain  more  than  40  parts  in  100,000  of  solid  matter;  pro- 
ided  that  a  large  proportion  of  the  solid  matter  does  not  consist  of 
Its  having  a  medicinal  action,  and  that  sulfurous  gases  and  sulfids 
re  absent. 

Artesian  wells  are  artificial  springs,  produced  by  boring  in  a  low- 
lying  district,  until  a  pervious  layer,  between  two  impervious  strata, 
is  reached;  the  outcrop  of  the  system  being  in  an  adjacent  elevated 
region . 

Impurities  in  Potable  Waters. — A  water  to  be  fit  for  drinking 
purposes  should  be  cool,  limpid  and  odorless;  it  should  have  an  agree- 
able taste,  neither  flat,  salty,  nor  sweetish,  and  it  should  dissolve 
soap  readily,  without  formation  of  any  flocculent  precipitate.  But, 
while  it  is  safe  to  condemn  a  water  which  does  not  possess  the  above 
characters,  it  is  by  no  means  safe  to  regard  all  waters  which  do 
possess  them  as  beyond  suspicion.  The  most  dangerous  of  all  con- 
taminations of  drinking  waters  is  by  admixture  of  sewage,  which 
may  be  present  in  a  water  in  quantity  sufficient  to  render  it  unfit  for 
use  and  the  water  yet  retain  all  of  the  characters  of  a  good  water 
above  referred  to.  To  determine  whether  a  water  is  really  fit  for 
drinking  a  chemical  analysis  is  necessary,  and  a  bacteriological  exami- 
nation is  desirable.  For  the  methods  of  chemical  analysis  the  student 
is  referred  to  treatises  on  that  subject.  The  constituents  usually 
determined,  and  the  interpretation  of  the  results,  are  as  follows: 

Total  Solids. — The  amount  of  solid  material  dissolved  in  potable 
waters  varies  from  4.3  to  50  in  100,000  (2.5  to  29.2  grains  per  U.  S. 
gal.) ;  and  a  water  containing  more  than  the  latter  quantity  is  to  be 
condemned  on  that  account  alone. 

Chlorids. — The  presence  of  the  chlorids  of  the  alkaline  metals,  in 
quantities  not  sufficient  to  be  detectable  by  the  taste,  is  of  no  im- 
portance per  se ;  but  in  connection  with  the  presence  of  organic  im- 
purity, a  determination  of  the  amount  of  chlorin  affords  a  ready 
method  of  indicating  the  probable  source  of  the  organic  contamina- 
tion. As  vegetable  organic  matter  brings  with  it  but  small  quantities 
of  chlorids,  while  animal  contaminations  are  rich  in  those  compounds, 
the  presence  of  a  large  amount  of  chlorin  serves  to  indicate  that 
organic  impurity  is  of  animal  origin.  Indeed,  when  time  presses,  as 
during  an  epidemic,  it  is  best  to  rely  upon  determinations  of  chlorin. 
and  condemn  all  waters  containing  more  than  1.7  in  100,000  (1  grain 
per  U.  S.  gal.)  of  that  element. 


72  MANUAL    OP    CHEMISTRY 

Hardness. — The  greater  part  of  the  solid  matter  dissolved  in 
natural  fresh  waters  consists  of  the  salts  of  calcium,  accompanied  by 
less  quantities  of  the  salts  of  magnesium.  The  calcium  salt  is 
usually  the  bicarbonate  or  the  sulfate;  sometimes  the  chlorid,  phos- 
phate, or  nitrate. 

A  water  containing  an  excess  of  calcareous  salt  is  said  to  be 
hard,  and  one  not  so  charged  is  said  to  be  soft.  If  the  hardness  be 
due  to  the  presence  of  the  bicarbonate  it  is  temporary,  if  due  to  the 
sulfate  it  is  permanent.  Calcium  carbonate  is  almost  insoluble  in 
pure  water,  but  in  the  presence  of  free  carbonic  acid  the  more  sol- 
uble bicarbonate  is  dissolved.  But,  on  the  water  being  boiled,  it  is 
decomposed,  with  precipitation  of  the  carbonate.  As  calcium  sul- 
fate is  held  in  solution  by  virtue  of  its  own,  albeit  sparing,  solu- 
bility, it  is  not  deposited  when  the  water  is  boiled. 

The  hardness  is  now  usually  reported  in  terms  of  calcium  car- 
bonate, CaCOs,  either  in  grains  per  gallon  or  parts  in  100,000.  It 
is  also  sometimes  reported  in  "degrees,"  which  represent  grains  of 
CaCOs  per  imperial  gallon.  Very  soft  waters  contain  about  SCaCOa 
in  100,000,  and  hard  waters  15  or  over.  Usually  a  water  containing 
more  than  20CaCO3  in  100,000  is  considered  too  hard  for  domestic 
use,  unless  softened  by  boiling.  But  a  water  is  not  to  be  con- 
demned solely  because  its  hardness  exceeds  this  limit,  because  in 
certain  limestone  districts  all  waters  are  very  hard. 

Waters  which  owe  their  hardness  to  excess  of  magnesium  salts, 
cause  intestinal  disturbances  in  those  not  habituated  to  them. 

Organic  Matter. — Technically,  organic  impurities  in  a  water  con- 
sist of  vegetable  or  animal  matters  containing  nitrogen.  We  have 
seen  that  the  quantity  of  chlorin  affords  an  indication  as  to  whether 
the  organic  impurity  found  to  be  present  is  of  vegetable  or  of  animal 
origin.  Animal  organic  contamination  has  its  origin  in  sewage,  and 
its  presence  consequently  indicates  that  the  water  is,  or  may  at  any 
moment  become,  the  means  of  transmitting  water-borne  diseases, 
such  as  typhoid  and  cholera. 

The  nitrogenous  substances  in  feces  and  urine  consist  of  albumi- 
nous bodies,  crystalline  organic  compounds  (such  as  urea,  leucin, 
etc.)  and  ammoniacal  salts.  By  the  action  of  micro-organisms, 
which  exist  in  the  soil  and  in  water,  the  albuminous  and  crystalline 
compounds  are  gradually  converted  into  ammonium  compounds, 
which  are  subsequently  oxidized  by  atmospheric  or  dissolved  oxygen, 
aided  by  bacterial  influence,  to  nitrites  and  later  to  nitrates.  Conse- 
quently the  amount  of  sewage  contamination,  and  the  degree  in  which 
such  contamination  has  been  subsequently  modified,  can  be  inferred 
from  quantitative  determinations  of  the  nitrogen  present  in  the  sev- 
eral forms  referred  to. 


WATER  73 

In  the  usual  process  of  water  analysis  the  following  factors  are 
letermined  quantitatively: 

A.  Albuminoid  ammonia,  which  represents  the  nitrogen  present 
albuminous  and  crystalline  combination. 

B.  Free  ammonia,  which  represents  the  ammoniacal  compounds. 

C.  Nitrogen  in  nitrates  and  nitrites,  and  D.  Nitrites. 

If  a  water  yield  no  albuminoid  ammonia  it  is  organically  pure, 
iven  if  it  contain  much  free  ammonia  and  chlorids.  If  it  contain 
un  .02  to  .05  milligrams  per  litre  (.002  to  .005  in  100,000)  it  is 
still  quite  pure.  When  the  albuminoid  ammonia  reaches  0.1  milligr. 
litre  (.01  in  100,000)  the  water  is  to  be  looked  upon  with  sus- 
)icion;  and  it  is  to  be  condemned  when  the  proportion  reaches  0.15 
(.015  in  100,000).  When  free  ammonia  is  also  present  in  consid- 
erable quantity,  a  water  yielding  0.05  (.005  in  100,000)  of  albumi- 
noid ammonia  is  to  be  looked  upon  with  suspicion. 

Nitrates  and  nitrites  are  present  in  rain  water  in  quantities  less 
than  0.5  parts  in  100,000,  calculated  as  nitrogen.  When  the  amount 
exceeds  this,  these  salts  are  considered  as  indicating  previous  con- 
tamination by  organic  matter  which  has  been  oxidized  and  whose 
nitrogen  has  been  to  some  extent  converted  into  nitrites  and  nitrates. 

The  quantity  of  nitrites  in  good  waters  does  not  exceed  .002  in 
100,000  when  they  are  present.  A  larger  quantity  is  considered  as 
indicating  previous  organic  contamination. 

In  some  processes  it  is  sought  to  measure  the  organic  contamina- 
tion by  the  amount  of  oxygen  consumed  in  their  oxidation  by  po- 
tassium permanganate.  As  these  results  take  no  account  of  other 
oxidations  which  may  take  place  they  are  not  reliable. 

Poisonous  Metals.  —  Natural  waters  containing  notable  quan- 
tities of  iron  compounds  belong  to  the  class  of  chalybeate  mineral 
waters.  Contact  with  metallic  iron  does  not  contaminate  water.  In 
districts  where  copper  deposits  exist  the  waters  sometimes  contain 
copper,  and  the  waters  of  some  streams  contain  arsenic. 

Lead  in  drinking  water  has  been  a  prolific  source  of  chronic  lead 
poisoning.  As  lead  is  only  dissolved  by  water  after  oxidation,  con- 
ditions favoring  oxidation  of  the  metal  favor  its  solution.  Such 
conditions  are:  the  presence  of  nitrates,  a  highly  aerated  condition 
of  the  water,  alternate  wetting  and  drying  of  the  surface  of  the  metal, 
the  absence  of  sulfates  and  carbonates,  and  the  presence  of  much 
carbonic  acid  dissolved  under  pressure  (soda  water).  Sulfates  and 
carbonates  prevent  solution  by  the  formation  of  a  protecting  coating 
of  an  insoluble  salt.  As  a  rule,  the  purer  the  water  the  more  liable 
it  is  to  dissolve  lead  when  brought  in  contact  with  that  metal,  espe- 
cially if  the  contact  occur  when  the  water  is  at  a  high  temperature, 
or  when  it  lasts  for  a  long  period. 


74  MANUAL    OF    CHEMISTRY 

Bacteriological  Examination  of  Water. — In  recent  years  much 
attention  has  been  given  to  the  examination  of  natural  waters  by 
bacteriological  methods,  plate  cultures  on  gelatin,  cultures  in  blood 
serum  and  on  potatoes,  and  experiments  on  animals.  Although  in 
some  instances  pathogenic  bacteria  have  been  found  in  water,  and 
although  in  the  future  valuable  results  will  probably  be  obtained  by 
these  methods,  the  chief  reliance  in  determining  the  quality  of  a 
drinking-water  is  still  to  be  placed  upon  the  older  chemical  processes. 

Purification  of  Water. — The  artificial  means  of  rendering  a  more 
or  less  contaminated  water  fit  for  use  are  of  five  kinds:  Distillation, 
subsidence,  filtration,  precipitation,  and  boiling. 

Distillation  is  resorted  to  in  the  laboratory  to  obtain  very  pure 
water,  also,  on  a  larger  scale,  to  purify  drinking  water.  When  dis- 
tilled water  is  to  be  used  for  drinking  it  should  be  aerated  and  charged 
with  salts  to  the  extent  of  about  0.03  gram  each  of  calcium  bicarbo- 
nate and  sodium  chlorid  to  the  litre. 

In  filtration  suspended  impurities  are  removed  more  or  less  com- 
pletely by  passing  the  water  through  a  porous  material.  In  filter 
beds,  used  to  filter  large  quantities  of  water,  sand  is  the  filtering 
material  used,  either  alone  or  combined  with  charcoal  or  spongy  iron. 
In  domestic  filters,  treating  small  quantities  of  water,  the  filtering 
material  is  quartz  sand,  charcoal,  porous  stone,  or  unglazed  earthen- 
ware or  porcelain.  Whatever  may  be  the  size  or  construction  of  the 
filter,  it  must  be  cleaned  periodically.  If  this  be  neglected  the  filter 
ceases  to  purify  the  water,  and  becomes  itself  a  source  of  contamina- 
tion. The  usual  method  of  cleaning  is  by  reversing  the  current 
through  the  filter  until  the  washings  come  away  clear.  Dissolved 
organic  matter  is  in  part  removed  by  oxidation  in  filtration  through 
sand  filter  beds  several  feet  in  thickness,  or  through  much  thinner 
layers  of  charcoal  or  porous  iron.  Typhoid  and  cholera  germs  pass, 
although  in  greatly  diminished  numbers,  through  all  filters  except 
those  made  of  unglazed  porcelain. 

Precipitation  methods  were  formerly  used  only  to  soften  tempor- 
arily hard  waters.  One  method  consists  in  the  addition  of  lime  water 
in  quantity  just  sufficient  to  convert  the  soluble  calcium  bicarbonate 
present  into  the  insoluble  carbonate.  At  present  precipitation 
methods  are  also  used,  in  combination  with  subsidence  and  filtration, 
to  remove  organic  impurities  ;  alum  or  a  ferric  salt  is  added,  an 
excess  being  avoided,  to  form  a  gelatinous  precipitate  which  carries 
the  impurities  down  with  it  mechanically  as  it  settles  when  the  water 
is  left  at  rest  in  the  subsidence  tanks;  the  water  is  drawn  off  from 
above  the  deposit  to  the  filters,  after  a  proper  interval.  Precipitation 
and  subsidence  are  thus  used  to  diminish  the  work  required  of  the 
filters. 


WATER  75 


The  purification  of  water  by  boiling  can  only  be  carried  on  on  a 
small  scale.  It  is  very  useful,  however,  to  soften  temporarily  hard 
waters  and,  particularly,  to  sterilize  infected  waters.  For  the  latter 
purpose  the  boiling  must  be  continued  actively  for  at  least  twenty 
minutes  in  a  vessel  closed  except  for  a  steam  outlet,  which  is  to  be 
stopped  with  a  plug  of  cotton  when  the  vessel  is  taken  off  to  cool. 

Natural  Purification  of  Water. —The  water  of  brooks,  rivers, 
and  lakes  which  have  been  contaminated  by  sewage  and  other  organic 
impurity  becomes  gradually  purified  by  natural  processes.  Sus- 
pended particles  are  deposited  upon  the  bottom  and  sides  of  the 
stream,  more  or  less  rapidly,  according  to  their  gravity  and  the 
rapidity  of  the  current.  The  bicarbonates  of  calcium,  magnesium, 
and  iron  gradually  lose  carbon  dioxid,  and  are  precipitated  as  car- 
bonates, which  mechanically  carry  down  dissolved  as  well  as  sus- 
pended impurities.  The  decompositions,  oxidations,  and  reductions 
to  which  organic  matters  are  subject  under  the  influence  of  atmos- 
pheric and  dissolved  oxygen  and  bacterial  action  bring  about  their 
gradual  mineralization  by  conversion  into  ammonia  and  then  into 
nitrates.  The  processes  of  nutrition  of  aquatic  plant  life  absorb 
dissolved  organic  impurity,  as  well  as  the  products  of  decomposition 
of  nitrogenized  substances.  This  natural  purification  proceeds  the 
more  rapidly  the  more  contact  with  air  is  favored. 

Mineral  Waters. — Under  this  head  are  classed  all  waters  which 
are  of  therapeutic  or  industrial  value,  by  reason  of  the  quantity  or 
nature  of  the  dissolved  solids  which  they  contain;  or  which  have  a 
temperature  greater  than  20°  (68°  F.). 

The  composition  of  mineral  waters  varies  greatly,  according  to  the 
nature  of  the  strata  or  veins  through  which  the  water  passes,  and  to 
the  conditions  of  pressure  and  previous  composition  under  which  it  is 
in  contact  with  these  deposits. 

Although  a  sharply  defined  classification  of  mineral  waters  is  not 
possible,  one  which  is  useful,  if  not  accurate,  may  be  made,  based 
upon  the  predominance  of  some  constituent,  or  constituents,  which 
impart  to  the  water  a  well-defined  therapeutic  value.  A  classifica- 
tion which  has  been  generally  adopted  includes  five  classes: 

I.  Acidulous  waters;  whose  value   depends  upon  dissolved  car- 
bonic acid.     They  contain  but  small  quantities  of  solids,  principally 
the  bicarbonates  of  sodium  and  calcium  and  sodium  chlorid. 

II.  Alkaline  waters ;  which  contain  quantities  of  the  bicarbonates 
of  sodium,  potassium,  lithium,  and  calcium,  sufficient  to  communi- 
cate to   them  an  alkaline  reaction,  and   frequently  a    soapy  taste  ; 
either  naturally,  or  after  expulsion  of  carbon  dioxid  by  boiling. 

III.  Chalybeate   waters  ;    which  contain  salts  of  iron  in  greater 
proportion   than  4  parts  in  100,000.     They  contain   ferrous   bicar- 


76  MANUAL    OF    CHEMISTRY 

bonate,  sulfate,  crenate,  and  apocrenate,  calcium  carbonate,  sulfates 
of  potassium,  sodium,  calcium,  magnesium,  and  aluminium,  notable 
quantities  of  sodium  chlorid,  and  frequently  small  amounts  of 
arsenic.  They  have  the  taste  of  iron  and  are  usually  clear  as  they 
emerge  from  the  earth.  Those  containing  ferrous  bicarbonate  de- 
posit a  sediment  on  standing,  by  loss  of  carbon  dioxid,  and  formation 
of  ferrous  carbonate. 

IV.  Saline  waters ;    which  contain  neutral  salts  in  considerable 
quantity.     The  nature  of  the  salts  which  they  contain  is  so  diverse 
that  the  group  may  well  be  subdivided  : 

a.  Chlorin  waters ;  which  contain  large  quantities  of  sodium 
chlorid,  accompanied  by  less  amounts  of  the  chlorids  of  potassium, 
calcium,  and  magnesium.  Some  are  so  rich  in  sodium  chlorid  that 
they  are  not  of  service  as  therapeutic  agents,  but  are  evaporated  to 
yield  a  more  or  less  pure  salt.  Any  natural  water  containing  more 
than  300  parts  in  100,000  of  sodium  chlorid  belongs  to  this  class, 
provided  it  do  not  contain  substances  more  active  in  their  medicinal 
action  in  such  proportion  as  to  warrant  its  classification  elsewhere. 
Waters  containing  more  than  1,500  parts  in  100,000  are  too  concen- 
trated for  internal  administration. 

^  Sulfate  waters  are  actively  purgative  from  the  presence  of 
considerable  proportions  of  the  sulfates  of  sodium,  calcium,  and 
magnesium.  Some  contain  large  quantities  of  sodium  sulfate,  with 
mere  traces  of  the  calcium  and  magnesium  salts,  while  in  others  the 
proportion  of  the  sulfates  of  magnesium  and  calcium  is  as  high  as 
3,000  parts  in  100,000  to  2,000  parts  in  100,000  of  sodium  sulfate. 
They  vary  much  in  concentration;  from  500  to  nearly  6,000  parts  of 
total  solids  in  100,000.  They  have  a  salty,  bitter  taste,  and  vary 
much  in  temperature. 

y.  Bromin  and  iodin  waters  are  such  as  contain  the  bromids  or 
iodids  of  potassium,  sodium,  or  magnesium  in  sufficient  quantity  to 
communicate  to  them  the  medicinal  properties  of  those  salts. 

V.  Sulfurous  waters;    which   hold    hydrogen    sulfid   or   metallic 
sulfids  in  solution.     They  have  a  disagreeable  odor  and  are  usually 
warm.     They  contain  20  to  400  parts  in  100,000  of  total  solids. 

Physiological. —  Water  is  taken  into  the  body  both  as  a  liquid 
and  as  a  constituent  of  every  article  of  food;  the  amount  ingested 
by  a  healthy  adult  being  2.25  to  2.75  litres  (2%  to  3  quarts)  per 
diem.  The  greater  the  elimination  and  the  drier  the  nature  of  the 
food  the  greater  is  the  amount  of  EbO  taken  in  the  liquid  form. 

Water  is  a  constituent  of  every  tissue  and  fluid  of  the  body,  vary- 
ing from  0.2  per  cent,  in  the  enamel  of  the  teeth  to  99.5  per  cent,  in 
the  perspiration  and  saliva.  It  constitutes  about  60  per  cent,  of  the 
weight  of  the  body. 


OXYGENATED    WATER  V? 

The  consistency  of  the  various  parts  does  not  depend  entirely  upon 
the  relative  proportion  of  solids  and  H2O,  but  is  influenced  by  the 
nature  of  the  solids.  The  blood,  although  liquid  in  the  ordinary  sense 
of  the  term,  contains  a  less  proportional  amount  of  H2O  than  does  the 
tissue  of  the  kidneys,  and  about  the  same  proportion  as  the  tissue  of 
the  heart.  Although  the  bile  and  mucus  are  not  as  fluid  as  the  blood, 
they  contain  a  larger  proportion  of  H2O  to  solids  than  does  that  liquid. 

Water  is  discharged  by  the  kidneys,  intestines,  skin,  and  pulmo- 
nary surfaces.  The  quantity  discharged  is  greater  than  that  ingested; 
the  excess  being  formed  in  the  body  by  the  oxidation  of  the  H  of  its 
organic  constituents. 

HYDROGEN  DIOXID. 
HYDROGEN    PEROXID — OXYGENATED    WATER. 

H2O2 —  Molecular  weight  =  34 — Sp.  gr.  =  1.455  —  Discovered  by 
Thenard  in  1818. 

Exists  naturally  in  very  minute  quantity  in  rain-water,  in  air,  and 
in  the  saliva. 

This  substance  may  be  obtained  in  a  state  of  purity  by  accurately 
following  the  process  of  Thenard.  It  may  also  be  obtained,  mixed 
with  a  large  quantity  of  H2O,  by  the  action  of  dilute  mineral  acids  on 
barium  peroxid:  BaO2+H2SO4  =  BaS(>4  +  H2O2.  It  is  also  formed 
in  small  quantity  during  the  slow  oxidation  of  many  elements  and 
compounds,  such  as  P,  Pb,  Zn,  Cd,  Al,  alcohol,  ether  and  the  essences. 

It  is  prepared  industrially  of  10-12  volume  strength  by  gradually 
adding  barium  peroxid  to  dilute  hydrofluoric  acid  solution,  the  mix- 
ture being  maintained  at  a  low  temperature  and  constantly  agitated; 
or,  in  still  greater  concentration  by  the  action  of  dilute  acids  on 
sodium  peroxid,  care  being  had  to  prevent  heating  of  the  mixture: 
Na2O2  +  2HCl==2NaCl+H2O2.  Hydrogen  peroxid  is  also  formed 
when  sodium  peroxid  is  dissolved  in  water:  Na2O2-f 2H2O=2NaHO 
+H2O2. 

The  pure  substance  is  a  colorless,  syrupy  liquid,  which,  when 
poured  into  H2O,  sinks  under  it  before  mixing.  It  has  a  disagreeable 
metallic  taste,  somewhat  resembling  that  of  tartar  emetic.  When 
taken  into  the  mouth  it  produces  a  tingling  sensation,  increases  the 
flow  of  saliva,  and  bleaches  the  tissues  with  which  it  comes  in  con- 
tact. It  is  still  liquid  at— 30°  (—22°  F.).  It  is  very  unstable,  and, 
even  in  darkness  and  at  ordinary  temperature,  is  gradually  decom- 
posed. At  20°  (68°  F.)  the  decomposition  takes  place  more  quickly 
and  at  100°  (212°  F.)  rapidly  and  with  effervescence.  The  dilute 
substance,  however,  is  comparatively  stable,  and  may  be  boiled  and 
even  distilled  without  suffering  decomposition.  Yet  it  is  liable  to 


78  MANUAL    OP    CHEMISTRY 

explosive  decomposition  when  exposed   to   summer   temperature   in 
closed  vessels. 

Hydrogen  peroxid  acts  both  as  a  reducing  and  an  oxidizing  agent. 
Arsenic,  sulfids,  and  sulfur  dioxid  are  oxidized  by  it  at  the  expense 
of  half  its  oxygen.  When  it  is  brought  in  contact  with  silver  oxid 
both  substances  are  violently  decomposed,  water  and  elementary 
silver  remaining.  By  certain  substances,  such  as  gold,  platinum, 
and  charcoal  in  a  state  of  fine  division,  fibrin,  or  manganese  dioxid, 
it  is  decomposed  with  evolution  of  oxygen;  the  decomposing  agent 
remaining  unchanged. 

The  pure  substance,  when  decomposed,  yields  475  times  its  vol- 
ume of  oxygen;  the  dilute  15  to  20  volumes. 

In  dilute  solution  it  is  used  as  a  bleaching  agent  and  in  the  reno- 
vation of  old  oil-paintings.  It  is  an  energetic  disinfectant  and  anti- 
septic, and  is  extensively  used  in  surgery.  "Ozonic  ether"  is  a  mix- 
ture of  ethylic  ether  and  dilute  hydrogen  peroxid. 

Analytical  Characters. — 1.  To  a  solution  of  starch  a  few  drops 
of  cadmium  iodid  solution  are  added,  then  a  small  quantity  of  the 
fluid  to  be  tested,  and,  finally,  a  drop  of  a  solution  of  ferrous  sul- 
fate.  A  blue  color  is  produced  in  the  presence  of  hydrogen  peroxid, 
even  if  the  solution  contain  only  0.05  milligram  per  litre. 

2.  Add  freshly -prepared  tincture  of  guaiacum  and  a  few  drops  of 
a  cold  infusion  of  malt.     A  blue  color  — 1  in  2,000,000. 

3.  Add  to  the  liquid  a  few  drops  of  potassium  dichromate  and 
a   little   dilute   sulfuric   acid,    and   agitate   with   ether.      The    ether 
assumes  a  brilliant  blue -violet  color. 

4.  Add  to  6  cc.  of  the  liquid  sulfuric  acid,  iodid  of  zinc,  starch- 
paste,  two  drops  of  a  2  per  cent,  solution  of  cupric  sulfate,  and  a 
little  one -half   per   cent,   solution   of   ferrous  sulfate,   in  the  order 
named.     A  blue  color. 

5.  Add  a  trace  of  acetic  acid,   some  a  naphthylamin  and  solid 
sodium  chlorid.     After  a  short  time  a  blue  or  blue -violet  color,  and 
after  some  hours  a  flocculent  ppt.  of  the  same  color. 

Atmospheric  Hydrogen  Dioxid. — It  has  been  claimed  that 
atmospheric  air,  rain-water,  snow,  and  hoar-frost  constantly  con- 
tain small  quantities  of  hydrogen  peroxid;  the, amount  in  rain-water 
varying  from  0.0008  to  0.05  part  in  100,000.  The  most  recent 
experiments  bearing  upon  the  supposed  presence  of  ozone  and 
hydrogen  peroxid  in  atmospheric  air  seem,  however,  to  justify  the 
belief  that  those  substances,  if  present  in  air  at  all,  are  not  met  with 
in  the  amounts  and  with  the  constancy  that  have  been  claimed. 
According  to  this  latter  view  the  appearances  from  which  the  pres- 
ence of  ozone  and  hydrogen  peroxid  has  been  inferred  are  not  caused 
by  those  substances,  but  by  nitrous  acid  and  the  oxids  of  nitrogen. 


FLUORIN 


79 


CLASS   II— ACIDULOUS   ELEMENTS. 

icnts  all  of   whose  Hydrates  are  Acids,  and  which  do  not  form  Salts  with 

the  Oxacids. 

I.    CHLORIN   GROUP. 

FLUORIN.      CHLORIN.      BROMIN.      IODIN. 

The  elements  of  this  group  are  univalent.  With  hydrogen  they 
form  acid  compounds,  composed  of  one  volume  of  the  element  in  the 
gaseous  state  with  one  volume  of  hydrogen.  Mineral  acids  in  which 
they  occur  are  monobasic.  The  first  two  are  gases,  the  third  liquffl, 
the  fourth  solid  at  ordinary  temperatures.  They  are  known  as  the 
halogens.  The  relations  of  their  compounds  to  each  other  are  shown 
in  the  following  table  : 


xar 
HC1 
HBr 
HI 

Hydro-ic 
acid. 

CloO 

C1204 

I204 

Tetroxid. 

Monoxid. 

HC1O 
HBrO 
HIO 

Hypo- 
ous  acid 

HC1O2 

HC1O3 
HBr03 
HIO3 

-ic  acid 

HC104 
HBr04 
HIO4 

Per-ic 
acid. 

HIO2 
-ous  acid. 

FLUORIN. 

8ymbol=Y— Atomic  weight=l9  (O=16:  19;  H=l:  18.85)—*. 
gr.  1.265  A  (calculated=l. 316)— Discovered  ly  Sir  H.  Davy  in  1812. 

Fluorin  has  been  isolated  by  the  electrolysis  of  pure,  dry  HF  at— 
23°  (—9.4°  F.).  It  exists  in  nature  chiefly  in  Fluor  Spar,  CaF2, 
and  in  cryolite,  Al2Fe  (NaF)e. 

It  is  a  gas,  colorless  in  thin  layers,  greenish  yellow  in  layers  50 
cent,  thick. 

It  decomposes  H2O,  with  formation  of  HF  and  ozone.  In  .it  Si, 
B,  As,  Sb,  S,  and  I  fire  spontaneously.  With  H  it  detonates  vio- 
lently, even  in  the  dark.  It  attacks  organic  substances  violently. 
The  apparatus  in  which  it  is  liberated  must  be  made  of  platinum  or 
fluor-spar.  It  forms  compounds  with  all  other  elements  except 
oxygen. 

Hydrogen  Fluorid.  —  Hydrofluoric  acid=KF— Molecular  weight 
=20.  Hydrofluoric  acid  is  obtained  by  the  action  of  an  excess  of 
sulfuric  acid  upon  fluor-spar  or  upon  barium  fluorid,  with  the  aid  of 
gentle  heat:  CaF2+H2SO4=CaSO4+2HF.  If  a  solution  be  desired, 
the  operation  is  conducted  in  a  platinum  or  lead  retort,  whose  beak  is 
connected  with  a  U-shaped  receiver  of  the  same  metal,  which  is 
cooled  and  contains  a  small  quantity  of  water. 


80  MANUAL    OF    CHEMISTRY 

The  pure  acid  is  a  colorless  liquid,  which  boils  at  19°  (67°F.)  ami 
solidifies  at— 1°  (30.2°  F.).  Sp.  gr.  0.985  at  12°  (53.6°  P.).  The 
aqueous  acid  is  a  colorless  liquid,  highly  acid  and  corrosive,  and 
having  a  penetrating  odor.  Great  care  must  be  exercised  that  neither 
the  solution  nor  the  gas  comejn  contact  with  the  skin,  as  they  pro- 
duce painful  ulcers  which  heal  with  difficulty,  and  also  constitutional 
symptoms  which  may  last  for  days.  The  inhalation  of  air  containing 
very  small  quantities  of  HF  has  caused  permanent  loss  of  voice,  and 
in  two  cases,  death.  When  the  acid  has  accidentally  come  in  contact 
with  the  skin  the  part  should  be  washed  with  dilute  solution  of  pot- 
ash, and  the  vesicle  which  forms  should  be  opened. 

Both  the  gaseous  acid  and  its  solution  remove  the  silica  from  glass, 
a  property  utilized  in  etching  upon  that  substance,  the  parts  upon 
which  no  action  is  desired  being  protected  by  a  coating  of  wax. 

The  presence  of  fluorin  in  a  compound  is  detected  by  reducing  the 
substance  to  powder,  moistening  it  with  sulfuric  acid  in  a  platinum 
crucible,  over  which  is  placed  a  slip  of  glass  prepared  as  above.  At 
the  end  of  half  an  hour  the  wax  is  removed  from  the  glass,  which 
will  be  found  to  be  etched  if  the  substance  examined  contained  a 
fluorid. 

CHLORIN. 

8ymbol=Cl— Atomic  tveight=35.5  (O=-16: 35.45 ;H  =  1:35.17)- 
Molecular  weight=71  Sp.  gr.=2A502  A — One  litre  weighs  3.17  grams 
— 100  cubic  inches  weigh  76.3  grains — Name  derived  from  x^°>P°*= 
yellowish  green — Discovered  by  Scheele  in  1774. 

Occurrence. — Only  in  combination,  most  abundantly  in  sodium 
chlorid. 

Preparation. —  (1)  By  heating  together  manganese  dioxid  and 
hydrochloric  acid  (Scheele):  MnO2+4HCl=MnCl2-f  2H2O-f  C12. 

This  and  similar  operations  are  usually  conducted  in  an  apparatus 
such  as  that  shown  in  Fig.  22.  The  earthenware  vessel  A  (which  on 
a  small  scale  may  be  replaced  by  a  glass  flask)  is  two -thirds  filled 
with  lumps  of  manganese  dioxid  of  the  size  of  hazelnuts  and  adjusted 
in  the  water  bath;  hydrochloric  acid  is  poured  in  through  the  safety - 
tube  and  the  bath  heated.  The  disengaged  gas  is  caused  to  bubble 
through  the  small  quantity  of  water  in  B,  is  then  dried  by  passage 
over  the  fragments  of  calcium  chlorid  in  C,  and  is  finally  collected  by 
displacement  of  air  in  the  vessel  D. 

When  the  vessel  A  has  become  half  filled  with  liquid  it  is  best  to 
decant  the  solution  of  manganous  chlorid,  wash  the  remaining  oxid 
with  water  and  begin  anew.  A  kilo  of  oxid  yields  257.5  litres  of  Cl. 

In  a  modification  of  this  process,  which  permits  of  the  more  easy 
recovery  of  the  manganese  dioxid,  nitric  acid  is  used  along  with 


CHLORIN 


81 


hydrochloric.  The  reaction  is:  2HCl+2HNO3-f MnC^^ 
-f2H2O+Cl2.  The  MnO2  and  HNO3  are  recovered  by  heating  the 
manganese  nitrate  to  190°  (374°  F.)  and  treating  the  vapor  with  air 
and  steam.  The  reactions  are:  MnCNOaJ^MnC^+^C^  and  N2(>4 
+H2O+O=2HNO3. 

(2)  By  the  action  of  manganese  dioxid  upon  hydrochloric  acid  in 
the  presence  of  sulfuric  acid,  manganous  sulfate  being  also  formed: 
MnO2+2HCH-H2SO4=MnSO4H-2H20+Cl2.     The    same   quantity  of 
chlorin  is  obtained  as  in  (1),  with  the  use  of  half  the  amount  of 
hydrochloric  acid. 

(3)  By  heating  a  mixture  of  one  part  each  of  manganese  dioxid 
and  sodium  chlorid,  with  three  parts  of  sulfuric  acid.     Hydrochloric 


Fia.  22. 

acid  and  sodium  sulfate  are  first  formed:  H2S04-f2NaCl=Na2SO4-f 
2HC1;  and  the  acid  is  immediately  decomposed  by  either  of  the  reac- 
tions indicated  in  (1)  and  (2),  according  as  sulfuric  acid  is  or  is  not 
present  in  excess. 

(4)  By  the   action  of   potassium  dichromate  upon  hydrochloric 
acid;   potassium  and  chromic  chlorids  being  also  formed:   K2Cr2O7-h 
14HCl=2KCl+Cr2Cl6+7H2O+3Cl2.     Two  parts  of  powdered  dichro- 
mate are  heated  with  17  parts  of  acid  of  sp.  gr.  1.16;    100  grams  of 
the  salt  yielding  22.5  litres  of  01. 

(5)  A  convenient  method  of  obtaining   chlorin  on  a  laboratory 
scale  is  by  the  use  of  "chlorin  cubes."     These  are  made  by  pressing 
together  1  part  of  plaster  of   Paris  and  4  parts  of  chlorid  of  lime 
(q.  v.),  cutting  into  small  cubes  and  drying.     The  cubes  are  used  in 


82  MANUAL    OF    CHEMISTRY 

one  of  the  forms  of  constant  apparatus  (Figs.  18,  19,  20),  with  dilute 
hydrochloric  acid,  Cl  being  evolved  at  the  ordinary  temperature. 

When  a  slow  evolution  of  Cl,  extending  over  a  considerable  period 
of  time,  is  desired,  as  for  ordinary  disinfection,  moistened  chlorid  of 
lime  is  exposed  to  the  air,  the  calcium  hypochlorite  being  decomposed 
by  the  atmospheric  carbon  dioxid.  If  a  more  rapid  evolution  of  gas 
be  desired,  the  chlorid  of  lime  is  moistened  with  dilute  hydrochloric 
acid  in  place  of  with  water. 

(6)  By  the  action  of  potassium  chlorate  upon  hydrochloric  acid 
Cl  is  liberated,  slowly  at  the  ordinary  temperature,  more  rapidly  at 
the  temperature  of  the  water -bath  : 

2KC1O3       +      4HC1      =       C12       +      C12O4      +      2KC1      +       2H2O. 
Potassium  Hydrochloric          Chlorin.  Chlorin  Potassium  Water. 

chlorate.  acid.  tetroxid.  chlorid. 

(7)  Chlorin  is  obtained  industrially  in  the  manufacture  of  caustic 
soda  by  the  electrolysis  of  NaCl. 

( 8 )  In  Deacon' s  process  cupric  oxid  is  used  as  a  "  contact  substance" 
to  oxidize  hydrochloric  acid.     The  reactions  are:   2CuCl2=Cu2Cl2+ 
C12,  then,  Cu2Cl2+O2=2CuO+Cl2,  and,  finally,  2CuO+4HCl=2CuCl2 
+2H2O.     As  the  O  is  derived  from  air  the  Cl  obtained  is  largely 
diluted  with  N. 

(9)  In  the  Solvay,  Weldon  and  Mond  processes  Cl  is  derived  from 
magnesium  chlorid  by  the  reaction:  2MgCl2+O2=2MgO+2Cl2. 

Properties. — Physical. — A  greenish  yellow  gas,  at  the  ordinary 
temperature  and  pressure;  it  has  a  penetrating  odor,  and  is,  even 
when  highly  diluted,  very  irritating  to  the  respiratory  passages. 
Being  soluble  in  H2O  to  the  extent  of  one  volume  to  three  volumes  of 
the  solvent,  it  must  be  collected  by  displacement  of  air,  as  shown  in 
Fig.  22.  A  saturated  aqueous  solution  of  Cl  is  known  to  chemists 
as  chlorin  water,  and  in  pharmacy  as  aqua  chlori  (U.  S.),  Liquor 
chlori  (Br.).  It  should  bleach,  but  not  redden,  litmus  paper. 
Under  a  pressure  of  6  atmospheres  at  0°  (32°  F.) ,  or  8%  atmospheres 
at  12°  (53.6°  F.),  Cl  becomes  an  oily,  yellow  liquid,  of  sp.  gr.  1.33; 
and  boiling  at — 33.6°  ( — 28. 5°  F.).  Liquid  chlorin,  transported  in 
lead -lined  steel  cylinders,  is  now  an  article  of  commerce. 

Chemical. — Chlorin  exhibits  a  great  tendency  to  combine  with 
other  elements,  with  all  of  which,  except  F,  O,  N,  and  C,  it  unites 
directly,  frequently  with  evolution  of  light  as  well  as  heat,  and 
sometimes  with  an  explosion.  With  H  it  combines  slowly,  to  form 
hydrochloric  acid,  under  the  influence  of  diffuse  daylight,  and  vio- 
lently in  direct  sunlight,  or  in  highly  actinic  artificial  lights.  A 
candle  burns  in  Cl  with  a  faint  flame  and  thick  smoke,  its  H  com- 
bining with  the  Cl,  while  carbon  becomes  free. 


CHLORIN  83 

At  a  red  heat  Cl  decomposes  H2O  rapidly,  with  formation  of 
hydrochloric,  chloric,  and  probably  hypochlorous  acids.  The  same 
change  takes  place  slowly  under  the  influence  of  sunlight,  hence 
chlorin  water  should  be  kept  in  the  dark  or  in  bottles  of  yellow 
glass. 

In  the  presence  of  H20,  chlorin  is  an  active  bleaching  and  disin- 
fecting agent.  It  acts  as  an  indirect  oxidant,  decomposing  H20, 
the  nascent  O  from  which  then  attacks  the  coloring  or  odorous 
principle. 

Chlorin  is  readily  fixed  by  many  organic  substances,  either  by 
addition  or  substitution.  In  the  first  instance,  as  when  Cl  and 
olefiant  gas  unite  to  form  ethylene  chlorid,  the  organic  substance 
simply  takes  up  one  or  more  atoms  of  chlorin:  C2H4+Cl2=:C2H4Cl2. 
In  the  second  instance,  as  when  Cl  acts  upon  marsh  gas  to  produce 
methyl  chlorid:  CH4+Cl2=CH3CH-HCl,  each  substituted  atom  of 
Cl  displaces  an  atom  of  H,  which  combines  with  another  Cl  atom  to 
form  hydrochloric  acid. 

Hydrogen  Chlorid  —  Hydrochloric  Acid  —  Muriatic  Acid  — 
Acidum  Hydrochloricum  (U.  S.;  Br.) — HC1 — Molecular  weight= 
36.5— Sp.  gr.  1.259  A— A  litre  weighs  1.6293  gram. 

Occurrence. — In  volcanic  gases  and  in  the  gastric  juice  of  the 
mammalia. 

Preparation. — (1)  By  the  direct  union  of  its  constituent  elements. 

(2)  By  the  action  of  sulfuric  acid  upon  a  chlorid,  a  sulfate  being 
at  the  same  time  formed:   H2S04-f  2NaCl=Na2SO4+2HCl. 

This  is  the  reaction  by  which  the  HC1  used  in  the  arts  is  produced. 

(3)  Hydrochloric  acid  is  also  formed  in  a  great  number  of  reac- 
tions, as  when  Cl  is  substituted  in  an  organic  compound. 

Properties. — Physical. — A  colorless  gas,  acid  in  reaction  and  taste, 
having  a  sharp,  penetrating  odor,  and  producing  great  irritation  when 
inhaled.  It  becomes  liquid  under  a  pressure  of  40  atmospheres  at  4° 
(39.2°  F.)  Its  critical  temperature  is  52°  (125.6°  F.)  and  its  critical 
pressure  83  atmospheres.  It  is  very  soluble  in  H2O,  one  volume  of 
which  dissolves  480  volumes  of  the  gas  at  0°  (32°  F.) 

Chemical. — Hydrochloric  acid  is  neither  combustible  nor  a  sup- 
porter of  combustion,  although  certain  elements,  such  as  K  and  Na, 
burn  in  it.  It  forms  white  clouds  on  contact  with  moist  air. 

Solution  of  Hydrochloric  Acid.— It  is  in  the  form  of  aqueous 
solution  that  this  acid  is  usually  employed  in  the  arts  and  in  phar- 
macy. It  is,  when  pure,  a  colorless  liquid  (yellow  when  impure), 
acid  in  taste  and  reaction,  whose  sp.  gr.  and  boiling-point  vary 
with  the  degree  of  concentration.  When  heated,  it  evolves  HC1, 
if  it  contain  more  than  20  per  cent,  of  that  gas,  and  H2O  if  it  con- 


84  MANUAL    OF    CHEMISTRY 

tain  less.  A  solution  containing  20  per  cent,  boils  at  111°  (232°  F.), 
is  of  sp.  gr.  1.099,  has  the  composition  HCl-f  8H2O,  and  distils 
unchanged. 

Commercial  muriatic  acid  is  a  yellow  liquid;  sp.  gr.  about  1.16; 
contains  32  per  cent.  HC1;  and  contains  ferric  chlorid,  sodium  chlorid; 
and  arsenical  compounds. 

Acidum  hydrochloricum   is    a   colorless   liquid,   containing   small 
quantities  of  impurities.     It  contains  31.9  per  cent.  HC1  and  its  sp. 
gr.  is  1.16  (U.  S.;  Br.)     The  dilute  acid  is  the  above  diluted  with 
water.     Sp.  gr.  1.049  =  10  per  cent  HC1  (U.  S.);   sp.  gr.  1.052  - 
10.5  per  cent.  HC1  (Br.) 

G.  P.  (chemically  pure)  acid  is  usually  the  same  as  the  strong 
pharmaceutical  acid  and  far  from  pure  (see  below).  The  strongest 
solution  has  a  sp.  gr.  of  1.20  and  contains  40.8  per  cent.  HC1. 

Hydrochloric  acid  is  classed,  along  with  nitric  and  sulfuric  acids, 
as  one  of  three  strong  mineral  acids.  It  is  decomposed  by  many 
elements,  with  formation  of  a  chlorid  and  liberation  of  hydrogen: 
2HCl+Zn=ZnCl2+H2.  With  oxids  and  hydroxids  of  the  metals  it 
enters  into  double  decomposition,  forming  H2O  and  a  chlorid:  CaO+ 
2HCl=CaCl2+H20  or  CaH202+2HCl=CaCl2+2H2O. 

Oxidizing  agents  decompose  HC1  with  liberation  of  Cl.  A  mix- 
ture of  hydrochloric  and  nitric  acids  in  the  proportion  of  three 
molecules  of  the  former  to  one  of  the  latter  (18  cc.  HNOs:  82  cc. 
HClsoln.),  is  the  acidum  nitrohydrochloricum  (U.  S.;  Br.),  or 
aqua  regia.  The  latter  name  alludes  to  its  power  of  dissolving  gold, 
by  combination  of  the  nascent  Cl,  which  it  liberates,  with  that  metal. 
to  form  the  soluble  auric  chlorid  (p.  111). 

Impurities. — A  chemically  pure  solution  of  this  acid  is  exceed- 
ingly rare.  The  impurities  usually  present  are:  Sulfurous  acid— 
hydrogen  sulfid  is  given  off  when  the  acid  is  poured  upon  zinc;  Sul- 
furic acid — a  white  precipitate  is  formed  with  barium  chlorid;  Chlorin 
colors  the  acid  yellow;  Lead  gives  a  black  color  when  the  acid  is 
treated  with  hydrogen  sulfld;  Iron — the  acid  gives  a  red  color  with 
ammonium  thiocyanate;  Arsenic — the  method  of  testing  by  hydrogen 
sulfid  is  not  sufficient.  If  the  acid  is  to  be  used  for  toxicological 
analysis,  a  litre,  diluted  with  half  as  much  H2O,  and  to  which  a 
small  quantity  of  potassium  chlorate  has  been  added,  is  evaporated 
over  the  water  bath  to  400  cc. ;  25  cc.  of  sulfuric  acid  are  then  added, 
and  the  evaporation  continued  until  the  liquid  measures  about  100  cc. 
This  is  introduced  into  a  Marsh  apparatus  and  must  produce  no 
mirror  during  an  hour. 

Chlorids. — A  few  of  the  chlorids  are  liquid,  SnCLi,  SbCls;  the 
remainder  are  solid,  crystalline  and  more  or  less  volatile.  The  me- 
tallic chlorids  are  soluble  in  water,  except  AgCl  and  Hg2Cl2,  which 


CHLORIN  $5 

are  insoluble,  and  PbCl2,  and  Cu2Cl2,  which  are  sparingly  soluble. 
The  chlorids  of  the  non-metals  are  decomposed  by  H20. 

The  chlorids  are  formed:  (1)  By  the  direct  union  of  the  ele- 
ments: P+C15=PC15;  (2)  By  the  action  of  chlorin  upon  a  heated 
mixture  of  oxid  and  carbon:  A12O3+3C+3C12=A12C16+3CO  ;  (3) 
By  solution  of  the  metal,  oxid,  hydroxid,  or  carbonate  in  HOI:  Zn+ 
2HCl=ZnCl2+H2;  (4)  By  double  decomposition  between  a  solution 
of  a  chlorid  and  that  of  another  salt  whose  metal  forms  an  insoluble 
chlorid:  AgNO3+NaCl=AgCl+NaNO3. 

Analytical  Characters.  —  (1)  With  AgNO3  a  white,  flocculent 
ppt.,  insoluble  in  HNO3,  soluble  in  NH4HO.  (2)  With  Hg2  (N03)2, 
a  white  ppt.,  which  turns  black  with  NILtHO. 

Toxicology. — Poisons  and  corrosives. — A  poison  is  any  sub- 
stance which,  being  in  solution  in  the  blood,  may  produce  death 
or  serious  bodily  harm. 

A  corrosive  is  a  substance  capable  of  producing  death  by  its 
chemical  action  upon  a  tissue  with  which  it  comes  in  direct 
contact. 

The  corrosives  act  much  more  energetically  when  concentrated 
than  when  dilute;  and  when  the  dilution  is  great  they  have  no  dele- 
terious action.  The  degree  of  concentration  in  which  the  true  poisons 
are  taken  is  of  little  influence  upon  their  action  if  the  dose  taken 
remain  the  same. 

Under  the  above  definitions  the  strong  mineral  acids  act  as  corro- 
sives rather  than  as  poisons.  They  produce  their  injurious  results  by 
destroying  the  tissues  with  which  they  come  in  contact,  and  will  cause 
death  as  surely  by  destroying  a  large  surface  of  skin,  as  when  they 
are  taken  into  the  stomach. 

The  symptoms  of  corrosion  by  the  mineral  acids  begin  immedi- 
ately, during  the  act  of  swallowing.  The  chemical  action  of  the  acid 
upon  every  part  with  which  it  comes  in  contact  causes  acute  burning 
pain,  extending  from  the  mouth  to  the  stomach  and  intestine,  referred 
chiefly  to  the  epigastrium.  Violent  and  distressing  vomiting  of  dark, 
tarry,  or  "coffee -ground,"  highly  acid  material  is  a  prominent  symp- 
tom. Eschars,  at  first  white  or  gray,  later  brown  or  black,  are  formed 
where  the  acid  has  come  in  contact  with  the  skin  or  mucous  mem- 
brane. Respiration  is  labored  and  painful,  partly  by  pressure  of  the 
abdominal  muscles,  but  also,  in  the  case  of  hydrochloric  acid,  from 
entrance  of  the  irritating,  acid  gas  into  the  respiratory  passages. 
Death  may  occur  within  twenty-four  hours,  from  collapse;  more 
suddenly  from  perforation  of  large  blood-vessels,  or  from  peritonitis; 
or  after  several  weeks,  secondarily,  from  starvation,  due  to  closure  of 
the  pylorus  by  inflammatory  thickening,  and  destruction  of  the  gastric 
glands. 


86  MANUAL    OF    CHEMISTRY 

The  object  of  the  treatment  in  corrosion  by  the  mineral  acids  is  to 
neutralize  the  acid  and  convert  it  into  a  harmless  salt.  For  this  pur- 
pose the  best  agent  is  magnesia  (magnesia  usta),  suspended  in  a  small 
quantity  of  water,  or  if  this  be  not  at  hand,  a  strong  solution  of  soap. 
Chalk  and  the  carbonates  and  bicarbonates  of  sodium  and  potassium 
should  not  be  given,  as  they  generate  large  volumes  of  gas.  The 
scrapings  of  a  plastered  wall,  or  oil,  are  entirely  useless.  Any  attempt 
at  the  introduction  of  a  tube  into  the  oesophagus  is  attended  with 
danger  of  perforation,  except  in  the  earliest  stages  of  the  intoxication. 

Compounds  of  Chlorin  and  Oxygen. — Two  compounds  of  chlorin 
and  oxygen  are  known.  They  are  both  very  unstable,  and  prone  to 
sudden  and  violent  decomposition. 

Chlorin  Monoxid. — C12O — 87 — Hypochlorous  anhydrid  or  oxid,  is 
formed  by  the  action,  below  20°  (68°  F.),  of  dry  Cl  upon  precipi- 
tated mercuric  oxid:  HgO+2Cl2=HgCl2+Cl2O. 

On  contact  with  H2O  it  forms  hypochlorous  acid,  HC1O,  which 
owing  to  its  instability,  is  not  used  industrially,  although  the  hypo- 
chlorites  of  Ca,  K,  and  Na  are. 

Chlorin  Tetroxid — Chlorin  peroxid,  ChO*— 135— is  a  violently 
explosive  body,  produced  by  the  action  of  sulfuric  acid  upon  potas- 
sium chlorate.  Below— 20°  ( — 4°  F.)  it  is  an  orange -colored  liquidi 
above  that  temperature  a  yellow  gas.  It  explodes  violently  when 
heated  to  a  temperature  below  100°  (212°  F.),  There  is  no  corre- 
sponding hydrate  known,  and  if  it  be  brought  in  contact  with  an 
alkaline  hydroxid,  a  mixture  of  chlorate  and  chlorite  is  formed. 

Besides  the  above,  two  oxacids  of  01  are  known,  the  anhydrids 
corresponding  to  which  have  not  been  isolated. 

Chloric  Acid — HClOs — 84.5 — obtained,  in  aqueous  solution,  as 
a  strongly  acid,  yellowish,  syrupy  liquid,  by  decomposing  its  barium 
salt  by  the  proper  quantitity  of  sulfuric  acid. 

Perchloric  Acid — HC1O4 — 100.5 — is  the  most  stable  of  the  series. 
It  is  obtained  by  boiling  potassium  chlorate  with  hydrofluosilicic 
acid,  decanting  the  cold  fluid,  evaporating  until  white  fumes  appear, 
decanting  from  time  to  time,  and  finally  distilling.  It  is  a  colorless, 
oily  liquid;  sp.  gr.  1.782;  which  explodes  on  contact  with  organic 
substances  or  charcoal. 

BROMIN. 

Bromum,  U.  S.,  Br. — Symbol=~Br. — Atomic  weight=SO — (O=16: 
79.06;  H=l:  79.32)— Molecular  weight=160—8p.  gr.  of  liguid= 
3.1872  at  0°;  of  vapor=5.52  A— Freezing  point=  —  24.5°  (—.12.1° 
F.) — Boiling  point=63°  (145.4°  F.) — Name  derived  from  /? 
stench — Discovered  by  Balard  in  1826. 


1BEOMIN  87 

Occurrence.— Only  in   combination,   most   abundantly  with   Na 
nd  Mg  in  sea  water  and  the  waters  of  mineral  springs. 
Preparation. — It  is  obtained  from  the  mother  liquors,  left  by  the 
evaporation  of* sea  water,  and  of  that  of  certain  mineral  springs,  and 
from  sea  weed.     These  are  mixed  with  sulfuric  acid  and  manganese 
dioxid  and  heated,  when  the  bromids  are  decomposed  by  the  Cl  pro- 
uced,  and  Br  distils. 

Properties. — Physical. — A  dark  reddish -brown  liquid,  volatile  at 
all  temperatures  above — 24.5°  ( — 12.1°  F.);  giving  off  brown-red 

E.pors   which   produce    great  irritation   when   inhaled.     Soluble   in 
iter    to   the   extent   of   3.2  parts  per   100  at  15°   (59° F.);    more 
luble  in  alcohol,  carbon  disulfid,  chloroform,  and  ether. 
Chemical. —  The  chemical  characters  of  Br  are  similar  to  those 
vj.  Cl,  but  less  active. — With  H2O  it  forms  a  crystalline  hydrate  at 
0°(32°  F) :  BrSIbO.    Its  aqueous  solution  is  decomposed  by  exposure 
to  light,  with  formation  of  hydrobromic  acid. 
It  is  highly  poisonous. 

Hydrogen  Bromid — Hydrobromic  acid — Acidum  hydrobromi- 
cum  dil.  (U.  S.)  =  HBr—-  Molecular  weight=Sl  —  8p.  gr.  =  2.71 
A— A  litre  weighs  3.63  grams— Liquefies  at  —  69°  (— 92°.2  F.)  — 
Solidifies  at— 73° (—99. 4°  F.). 

Preparation. — This  substance  cannot  be  obtained  from  a  bromid 
as  HC1  is  obtained  from  a  chlorid.  It  is  produced,  along  with 
phosphorous  acid,  by  the  action  of  H2O  upon  phosphorus  tribro- 
mid:  PBrs+SH^O^HsPOs+SHBr;  or  by  the  action  of  Br  upon 
paraffin. 

Properties. — A  colorless  gas;,,  produces  white  fumes  with  moist 
air;  acid  in  taste  and  reaction,  and  readily  soluble  in  H20,  with 
which  it  forms  a  hydrate,  HBr2H2O.  Its  chemical  properties  are 
similar  to  those  of  HC1. 

Bromids  closely  resemble  the  chlorids  and  are  formed  under 
similar  conditions.  They  are  decomposed  by  chlorin,  with  forma- 
tion of  a  chlorid  and  liberation  of  Br:2KBr+ Cl2=2KCl+ Br2.  The 
metallic  bromids  are  soluble  in  H2O,  except  AgBr  and  Hg2Br2,  which 
are  insoluble,  and  PbBr2,  which  is  sparingly  soluble.  The  bromids 
of  Mg,  Al,  Ca  are  decomposed  into  oxid  and  HBr  on  evaporation 
of  their  aqueous  solutions. 

Analytical   Characters.— (1)    With   AgNOa,    a    yellowish   white 
ppt.,  insoluble  in  HNO3,   sparingly   soluble  in  NH4HO.     (2. 
chlorin  water  a  yellow  solution  which  communicates  the  same  color 
to  chloroform  and  to  starch -paste. 

Oxacids  of  Bromin.— No  oxids  of  bromin  are  known,  although 
three  oxacids  exist,  either  in  the  free  state  or  as  salts: 


88  MANUAL    OF    CHEMISTRY 

Hypobromous  Acid — HBrO 97 — is  obtained,  in  aqueous  solu- 
tion, by  the  action  of  Br  upon  mercuric  oxid,  silver  oxid,  or  silver 
nitrate.  When  Br  is  added  to  concentrated  solution  of  potassium 
hydroxid  no  hypobromite  is  formed,  but  a  mixture  of  bromate  and 
brornid,  having  no  decolorizing  action.  With  sodium  hydroxid, 
however,  sodium  hypobromite  is  formed  in  solution;  and  such  a 
solution,  freshly  prepared,  is  used  in  Knop's  process  for  determin- 
ing urea  (q.  v.). 

Bromic  Acid — HBrOa — 129 — has  only  been  obtained  in  aqueous 
solution,  or  in  combination.  It  is  formed  by  decomposing  barium 
bromate  with  an  equivalent  quantity  of  sulfuric  acid:  Ba  (BrOsh-h 
H2S04— 2HBrO3+BaSO4.  In  combination  it  is  produced,  along  with 
the  bromid,  by  the  action  of  Br  on  caustic  potassa :  3Br2-h6KHO= 
KBrO3+5KBr-f3H2O. 

Perbromic  Acid — HBrCU — 145 — is  obtained  as  a  comparatively 
stable,  oily  liquid,  by  the  decomposition  of  perchloric  acid  by  Br, 
and  concentrating  over  the  water -bath. 

_It  is^noticeable  in  this  connection  that,  while  HC1  and  the 
chlorids  are  more  stable  than  the  corresponding  Br  compounds  the 
oxygen  compounds  of  Br  are  more  permanent  than  those  of  Cl. 

IODIN. 

lodum  (U.  S.;  Br.)—  Symbol  =  I  —  Atomic  weight=l27  (O=16: 
126.85;  H=l:125.84)—  Molecular  weight=254:—Sp.  gr.  of  solid= 
4.948;  of  vapor=S.716  A— Fuses  at  113.6°  (236.5°  F.)—  Boils  at 
175°  (347°  .F.) — Name  derived  from  i<*>fy?=  violet  — Discovered  by 
Courtois  in  1811. 

Occurrence. — In  combination  with  Na,  K,  Ca,  and  Mg,  in  sea- 
water,  the  waters  of  mineral  springs,  marine  plants  and  animals. 
Cod -liver  oil  contains  about  37  parts  in  100,000. 

Preparation. — It  is  obtained  from  the  ashes  of  sea-weed,  called 
kelp  or  varech.  These  are  extracted  with  E^O,  and  the  solution 
evaporated  to  small  bulk.  The  mother  liquor,  when  separated  from 
the  other  salts  which  crystallize  out,  contains  the  iodids,  which 
are  decomposed  by  Cl,  aided  by  heat,  and  the  liberated  iodin  is  con^j 
densed. 

Properties.  —  Physical.  —  Blue-gray,  crystalline  scales,  having  a 
metallic  luster.  Volatile  at  all  temperatures,  the  vapor  having  a 
violet  color,  and  a  peculiar  odor.  It  is  sparingly  soluble  in  EbO, 
which,  however,  dissolves  larger  quantities  on  standing  over  an 
excess  of  iodin,  by  reason  of  the  formation  of  hydriodic  acid.  The 
presence  of  certain  salts,  notably  potassium  iodid,  increases  the 


IODIN 


to 

: 


solvent  power  of  H2O  for  iodin.  The  Liq.  lodi  Comp.  ( U.  8.), 
Liq.  lodi,  Br.  is  a  solution  of  iodin  in  a  solution  of  potassium  iodid. 
Very  soluble  in  alcohol;  Tinct.  iodi  ( U.  S.;  Br.),  in  ether,  chloro- 
form, benzene,  and  carbon  disulfid.  With  the  three  last-named 
1  vents  it  forms  violet  solutions,  with  the  others  brown  solutions. 

Chemical. — In  its  chemical  characters  I  resembles  Cl  and  Br,  but 

less  active.  It  decomposes  H2O  slowly  and  is  a  weak  bleaching 
and  oxidizing  agent.  In  presence  of  water,  it  decomposes  hydrogen 
sulfid  with  formation  of  hydriodic  acid,  and  liberation  of  sulfur. 
It  does  not  combine  directly  with  oxygen,  but  does  with  ozone. 
Potassium  hydroxid  solution  dissolves  it,  with  formation  of  potas- 
sium iodid,  and  some  hypoiodite.  Nitric  acid  oxidizes  it  to  iodic 
acid.  With  ammonium  hydroxid  solution  it  forms  the  explosive 
nitrogen  iodid. 

Impurities. — Non-volatile  substances  remain  when  the  I  is  heated. 
Water  separates  as  a  distinct  layer  when  I  is  dissolved  in  carbon 
disulfid.  Cyanogen  iodid  appears  in  white,  acicular  crystals  among 
the  crystals  of  sublimed  I,  when  half  an  ounce  of  the  substance  is 
heated  over  the  water-bath  for  twenty  minutes,  in  a  porcelain  capsule, 
covered  with  a  flat -bottomed  flask  filled  with  cold  water.  The  last 
named  is  the  most  serious  impurity,  as  it  is  actively  poisonous. 

Toxicology. — Taken  internally,  iodin  acts  both  as  a  local  irritant 
and  as  a  true  poison.  It  is  discharged  as  an  alkaline  iodid  by  the 
urine  and  perspiration,  and  when  taken  in  large  quantity  it  appears 
in  the  faeces. 

The  poison  should  be  removed  as  rapidly  as  possible  by  the  use  of 
the  stomach  pump  and  of  emetics.  Farinaceous  substances  may  also 
be  given. 

Hydrogen  Iodid— Hydriodic  acid— HI— Molecular  weight=127 .85 
—Sp.  gr.  4.443  A. 

Preparation.— By  the  decomposition  of  phosphorus  triiodid  by 
water:  PI3H-3H2O=H3PO3+3HI.  Or,  in  solution  by  passing  hydro- 
gen sulfid  through  water  holding  iodin  in  suspension:  H2S+l2= 
2HH-S. 

Properties — A  colorless  gas,  forming  white  fumes  on  contact 
with  air,  and  of  strongly  acid  reaction.  Under  the  influence  of  cold 
and  pressure  it  forms  a  yellow  liquid,  which  solidifies  at  — 55°  (—67° 
F. ) .  Water  dissolves  it  to  the  extent  of  425  volumes  for  each  volume 
of  the  solvent  at  10°  (50°  F.) . 

It  is  partly  decomposed  into  its  elements  by  heat.  Mixed  with  O 
it  is  decomposed,  even  in  the  dark,  with  formation  of  EbO  and  liber- 
ation of  I.  Under  the  influence  of  sunlight  the  gas  is  slowly  decom- 
posed, although  its  solutions  are  not  so  affected,  if  they  be  free  from 


90  MANUAL    OF    CHEMISTRY 

air.  Chlorin  and  bromin  decompose  it,  with  liberation  of  iodin. 
With  many  metals  it  forms  iodids.  It  yields  up  its  H  readily  and  is 
used  in  organic  chemistry  as  a  source  of  that  element  in  the  nascent 
state. 

Iodids  are  formed  under  the  same  conditions  as  the  chlorids  and 
bromids,  which  they  resemble  in  their  properties.  The  metallic  iodids 
are  soluble  in  water  —  except  Agl,  Hg2l2,  which  are  insoluble, 
and  Pbl2,  which  is  very  slightly  soluble.  The  iodids  of  the  earth 
metals  are  decomposed  into  oxid  and  HI  on  evaporation  of  their 
aqueous  solutions.  Chlorin  decomposes  the  iodids  as  it  does  the 
bromids. 

Analytical  Characters. — (1)  With  AgNOa,  a  yellow  ppt.,  insol- 
uble in  HNO3,  and  in  NH4HO.  (2)  With  fuming  HNO3  or  with 
chlorin  water,  a  yellow  liquid,  which  colors  starch -paste  black  or 
purple,  and  chloroform  or  carbon  disulfid  violet. 

Chlorids  of  Iodin. — Chlorin  and  iodin  combine  with  each  other  in 
two  proportions :  Iodin  monochlorid,  or  protochlorid — IC1  is  a  red- 
brown,  oily,  pungent  liquid,  formed  by  the  action  of  dry  Cl  upon  I, 
and  distilling  at  100°  (212°  F.).  Iodin  trichlorid,  or  perchlorid— 
ICls  is  a  yellow,  crystalline  solid,  having  an  astringent,  acid  taste 
and  a  penetrating  odor;  very  volatile;  its  vapor  irritating;  easily 
soluble  in  water.  It  is  formed  by  saturating  EbO  holding  I  in  sus- 
pension with  Cl,  and  adding  concentrated  sulfuric  acid.  ICla  has 
been  used  as  an  antiseptic. 

Oxacids  of  Iodin. — The  best  known  of  these  are  the  highest  two 
of  the  series — iodic  and  periodic  acids. 

lodic  Acid — HIOs — 176.85  is  formed  as  an  iodate,  whenever  I  is 
dissolved  in  a  solution  of  an  alkaline  hydroxid:  le+GKHO^KIOa-h 
5KIH-3H20.  As  the  free  acid,  by  the  action  of  strong  oxidizing 
agents,  such  as  nitric  acid,  or  chloric  acid,  upon  I;  or  by  passing  Cl 
for  some  time  through  H2O  holding  I  in  suspension. 

Iodic  acid  appears  in  white  crystals,  decomposable  at  170°  (338° 
F.),  and  quite  soluble  in  H2O,  the  solution  having  an  acid  reaction, 
and  a  bitter,  astringent  taste. 

It  is  an  energetic  oxidizing  agent,  yielding  up  its  O  readily,  with 
separation  of  elementary  I  or  of  HI.  It  is  used  as  a  test  for  the 
presence  of  morphin  (q.  v.). 

Periodic  Acid— HIO4— 191.85— is  formed  by  the  action  of  Cl 
upon  an  alkaline  solution  of  sodium  iodate.  The  sodium  salt  thus 
obtained  is  dissolved  in  nitric  acid,  treated  with  silver  nitrate,  and 
the  resulting  silver  periodate  is  then  decomposed  with  H2O.  From 
the  solution  the  acid  is  obtained  in  colorless  crystals,  fusible 
at  130°  (266°  F.),  very  soluble  in  water,  and  readily  decomposable 
by  heat. 


SULFUR 


91 


II.    SULFUR   GROUP. 

SULFUR.      SELENIUM.      TELLURIUM. 

The  elements  of  this  group  are  bivalent  in  most  of  their  com- 
mnds,  in  some  they  are  quadrivalent  or  hexavalent.    With  hydrogen 
they  form  compounds  composed  of  one  volume  of  the  element,  in  the 
form  of   vapor,   with  two  volumes  of   hydrogen  —  the  combination 
>ing  attended  with  a  condensation  in  volume  of  one -third.     Mineral 
;ids  in  which  they  occur  are  dibasic.     They  are  all  solids  at  ordi- 
:y  temperatures.     The  relation  of  their  compounds  to  each  other  is 
town  in  the  following  table: 


H2S 

H2Se 

H2Te 

Hydro-ic  acid. 


S02 
SeO2 
Te02 
Dioxid. 


S03 

SeO3 

Te03 

Trioxid. 


H2S02 


Hypo-ous  acid. 


H2S03 
H2SeO3 
H2Te03 
-ous  acid. 


H2S04 
H2SeO4 
H2TeO4 
-ic  acid. 


SULFUR. 

Symbol  —  S  —  Atomic  weight  =  32 (0  =  16: 32.06;  H  =  1:31.8)— 
Molecular  weight  =64 — Sp.  gr.  of  vapor =2.22  A — Fuses  at  114° 
(237.2°  F.)— Boils  at  447.3°  (837°  F.). 

Occurrence. — Free  in  crystalline  powder,  large  crystals,  or 
amorphous,  in  volcanic  regions.  In  combination  in  sulfids  and  sul- 
fates,  and  in  protein  substances. 

Preparation.  — By  purification  of  the  native  sulfur  or  decomposi- 
tion of  pyrites,  natural  sulfids  of  iron. 

Crude  sulfur  is  the  product  of  the  first  distillation.  A  second 
distillation,  in  more  perfectly  constructed  apparatus,  yields  refined 
sulfur.  During  the  first  part  of  'the  distillation,  while  the  air  of 
the  condensing  chamber  is  still  cool,  the  vapor  of  S  is  suddenly  con- 
densed into  a  fine,  crystalline  powder,  which  is  flowers  of  sulfur, 
sulfur  sublimatum  ( 17.  S. ) .  Later,  when  the  temperature  of  the 
condensing  chamber  is  above  114°,  the  liquid  S  collects  at  the  bot- 
tom, whence  it  is  drawn  off  and  cast  into  sticks  of  roll  sulfur. 

Properties. — Physical. — Sulfur  is  usually  yellow  in  color.  At 
low  temperature,  and  in  minute  subdivision,  as  in  the  precipitated 
milk  of  sulfur,  sulfur  prsecipitatum  (U.  S.),  it  is  almost  or  quite 
colorless.  Its  taste  and  odor  are  faint  but  characteristic.  At  114° 
(237.2°  F)  it  fuses  to  a  thin  yellow  liquid,  which  at  150°-160° 
(302°- 320°  F.)  becomes  thick  and  brown;  at  330°- 340°  (626- 
642.2°  F.)  it  again  becomes  thin  and  light  in  color;  finally  it  boils, 
giving  off  brownish  yellow  vapor  at  a  temperature  variously  stated 


92  MANUAL    OF    CHEMISTRY 

between  440°  (824°  F.)  and  448°  (838.4°  F.).  If  heated  to  about 
400°  (752°  F.)  and  suddenly  cooled,  it  is  converted  into  plastic  sul- 
fur, which  may  be  moulded  into  any  desired  form.  It  is  insoluble 
in  water,  sparingly  soluble  in  anilin,  phenol,  benzene,  petroleum 
ether,  and  chloroform;  readily  soluble  in  sulfur  chlorid,  82012,  and 
carbon  disulfid.  It  dissolves  in  hot  alcohol,  and  crystallizes  from  the 
solution,  on  cooling,  in  white  prismatic  crystals.  It  is  dimorphous. 
When  fused  sulfur  crystallizes  it  does  so  in  oblique  rhombic  prisms. 
Its  solution  in  carbon  disulfid  deposits  it  on  evaporation  in  rhombic 
octahedra.  The  prismatic  variety  is  of  sp.  gr.  1.95  and  fuses  at  120° 
(248°  F.);  the  sp.  gr.  of  the  octahedral  is  2.05  and  its  fusing  point 
114.5°  (238°  F.).  The  prismatic  crystals,  by  exposure  to  air,  become 
opaque,  by  reason  of  a  gradual  conversion  into  octahedra. 

Chemical. — Sulfur  unites  readily  with  other  elements,  especially 
at  high  temperatures.  Heated  in  air  or  O,  it  burns  with  a  blue  flame 
to  sulfur  dioxid,  S(>2.  In  H  it  burns  with  formation  of  hydrogen  sulfid, 
H2S.  The  compounds  of  S  are  similar  in  constitution,  and  to  some 
extent  in  chemical  properties,  to  those  of  O.  In  many  organic  sub- 
stances S  may  replace  O,  as  in  thiocyanic  acid,  CNSH,  corresponding 
to  cyanic  acid,  CNOH.  Such  compounds  are  designated  by  the 
syllable  thio  ;  the  syllable  sulfo,  in  the  name  of  a  compound,  indicates 
that  it  contains  the  bivalent  group,  SC>2. 

Sulfur  is  used  principally  in  the  manufacture  of  gunpowder;  also 
to  some  extent  in  making  sulfuric  acid,  sulfur  dioxid,  and  matches, 
and  for  the  prevention  of  fungoid  and  parasitic  growths 

Hydrogen  Monosulfid — Sulfhydric  acid — Hydrosulfuric  acid — 
Sulfuretted  hydrogen— H2S — Molecular  weight=34— Sp.  gr.=1.19  A. 

Occurrence. — In  volcanic  gases;  as  a  product  of  the  decomposition 
of  organic  substances  containing  S;  in  solution,  in  the  waters  of 
some  mineral  springs;  and,  occasionally,  in  small  quantity,  in  the 
gases  of  the  intestine.  It  is  produced  from  proteins  and  other 
organic  substances  containing  S  by  microbic  action  (sulfhydric 
fermentation ) . 

Preparation. —  (1)  By  direct  union  of  the  elements;  either  by 
burning  S  in  H,  or  by  passing  H  through  molten  S. 

(2)  By  the  action  of  nascent  H  upon  sulfuric  acid,  if  the  mixture 
become  heated.     (See  Marsh  test  for  arsenic.) 

(3)  By  the  action  of  HC1  upon  antimony  trisulfid:  Sb2S3+6HCl= 
2SbCl3+3H2S. 

(4)  By  the  action  of  dilute  sulfuric  acid  upon  ferrous  sulfid:  FeS 
+H2SO4=FeSO4+H2S.      This  is  the  method  generally  used.     The 
gas  should  be  purified  by  passage  over  dry  calcium  chlorid,   then 
through  a  tube,  20  cent,  long,   loosely  filled  with  solid  iodin,  and, 


I 


SULFUR  93 


Ca 


finally,  through  a  solution  of  potassium  sulfid.  The  purpose  of  the 
iodin  is  to  arrest  traces  of  hydrogen  arsenid,  which  may  be  present. 

(5)  By  the  action   of   HC1  upon   calcium   sulfid:    CaS-h2HCl= 

C12+H2S. 

Properties.— Physical. — A  colorless  gas  having  the  odor  of  rotten 
eggs  and  a  disgusting  taste;  soluble  in  H2O  to  the  extent  of  3.23 
parts  to  1  at  15°  (59°  F.) ;  soluble  in  alcohol.  Under  17  atmospheres 
pressure,  or  at  — 74°  ( — 101.2°  F.)  at  the  ordinary  pressure,  it  lique- 
fies; at  —85.5°  (—122°  F.)  it  forms  white  crystals. 

Chemical. — Burns  in  air  with  formation  of  sulfur  dioxid  and  water: 
2H2S+3O2=2SO2+2H2O.  If  the  supply  of  oxygen  be  deficient,  H2O 
is  formed,  and  sulfur  liberated:  2H3S-j-02=2H2S+S2.  Mixtures  of 
H2S  and  air  or  O  explode  on  contact  with  flame.  Solutions  of  the  gas 
when  exposed  to  air  become  oxidized  with  deposition  of  S.  Such 
solutions  should  be  made  with  boiled  H20,  and  kept  in  bottles  which 
are  completely  filled,  and  well  corked.  Oxidizing  agents,  Cl,  Br,  and 
I  remove  its  H  with  deposition  of  S.  Hydrogen  sulfid  and  sulfur 
dioxid  mutually  decompose  each  other  into  water,  pentathionic  acid 
and  sulfur:  4SO2-f  3H2S= 2H2O+H2S5O6+S2. 

When  the  gas  is  passed  through  a  solution  of  an  alkaline  hy- 
droxid  its  S  displaces  the  O  of  the  hydroxid  to  form  a  sulfhydrate: 
H2S+KHO=H20+KHS.  With  solutions  of  metallic  salts  H2S 
usually  relinquishes  its  S  to  the  metal:  CuSO4+H2S=CuS+H2SO4, 
a  property  which  renders  it  of  great  value  in  analytical  chemistry. 

Physiological. — Hydrogen  sulfid  is  produced  in  the  intestine  by 
the  decomposition  of  protein  substances  or  of  taurochloric  acid; 
it  also  occurs  sometimes  in  abscesses,  and  in  the  urine  in  tubercu- 
losis, variola,  and  cancer  of  the  bladder.  It  may  also  reach  the 
bladder  by  diffusion  from  the  rectum. 

Toxicology. — An  animal  dies  almost  immediately  in  an  atmos- 
phere of  pure  H2S,  and  the  diluted  gas  is  still  rapidly  fatal.  An 
atmosphere  containing  1  per  cent  may  be  fatal  to  man,  although 
individuals  habituated  to  its  presence  can  exist  in  an  atmosphere 
containing  3  per  cent.  Even  when  highly  diluted  it  produces  a  con- 
dition of  low  fever,  and  care  is  to  be  taken  that  the  air  of  labora- 
tories in  which  it  is  used  shall  not  become  contaminated  with  it.  Its 
toxic  powers  are  due  primarily,  if  not  entirely,  to  its  power  of 
reducing  and  combining  with  the  blood -coloring  matter. 

The  form  in  which  hydrogen  sulfid  generally  produces  deleterious 
effects  is  as  a  constituent  of  the  gases  emanating  from  sewers,  privies, 
burial  vaults,  etc.  These  give  rise  to  either  slow  poisoning,  as  when 
sewer  gases  are  admitted  to  sleeping  and  other  apartments  by  de- 
fective plumbing,  or  to  sudden  poisoning,  as  when  a  person  enters  a 
vault  or  other  locality  containing  the  noxious  atmosphere. 


MANUAL    OF    CHEMISTRY 


The  treatment  should  consist  in  promoting  the  inhalation  of  pure 
air,  artificial  respiration,  cold  affusions,  and  the  administration  of 
stimulan 

After  death  the  blood  is  found  to  be  dark  in  color,  and  gives  the 
spectrum  shown  in  Fig.  23,  due  to  sulf haemoglobin. 

Sulfids   and    Hydrosulf ids.— These   compounds   bear   the   sam 
relation  to  sulfur  that  the  oxids  and  hydroxids  do  to  oxygen.     The 
two  sulfids  of  arsenic,  As2S3  and  As2S5,  correspond  to  the  two  oxids, 
As2O3  and  As2O5,and  the  potassium  hydrosulfid,  KHS,  corresponds  to 
the  hydroxid,  KHO. 

Many  metallic  sulfids  occur  in  nature,  and  are  important  ores  of 
the  metals,  as  the  sulfids  of  zinc,  mercury,  cobalt,  nickel,  and  iron. 
They  are  formed  artificially,  either  by  direct  union  of  the  elements  at 
elevated  temperatures,  as  in  the  case  of  iron:  Fe+S=FeS;  or  by 
reduction  of  the  corresponding  sulfate,  as  in  the  case  of  calcium: 
CaSO4-i-2C=CaS+2CO2. 

The  sulfids  are  insoluble  in  H2O,  except  those  of  the  alkali  metals. 
Many  of  the  sulfids  are  soluble  in  alkaline  liquids,  and  behave  as 


A*BC 


FIG.  23. 


thio-anhydnds,  forming  thio-salts,  corresponding  to  the  oxysalts. 
Thus  potassium  arsenate,  KsAsC^,  and  thioarsenate,  KsAsS^  anti- 
monate,  KaSbCU,  and  thioantimonate,  KaSbS^ 

The  metallic  sulfids  are  decomposed  when  heated  in  air,  usually 

with  the  formation  of  sulfur  dioxid  and  the  metallic  oxid;   sometimes 

with  the  formation  of  the  sulfate;  and  sometimes  with  the  liberation 

of  the  metal,  and  the  formation  of  sulfur  dioxid.     The  strong  mineral 

decompose  the  sulfids  with  formation  of  hydrogen  monosulfid. 

Analytical  Characters. — Hydrogen  Sulfid.  —  (1)  Blackens  paper 
••ned  with  lead  acetate  solution.  (2)  Has  an  odor  of  rotten 
eggs, 

N/////VN. — (i)  Heated  in  the  oxidizing  flame  of  the  blowpipe,  give 
a  blue  flame  and  odor  of  SO2.  (2)  With  a  mineral  acid  give  off  H2S 
(except  sulfids  of  Hg,  Au,  and  Pt). 

Hydrogen  Poly  sulfids. —Several  other  compounds  of  S  and  H, 
'•nm-pondiiiLr  to  the  polysulfids  of  K,  Na,  and  Ca,  are  known.  The 
Ifl  is  hydrogen  pentasulfid,  IIi»Sr,,  which  can  only  exist  in 
the  absence  of  water  and  at  low  temperatures. 


I 


SULFUR  95 

Sulfur  and  the  Halogens.  —  But  one  compound  of  S  and  Cl 
exists:  Sulfurous  chlorid,  82012,  formed  when  S  is  distilled  in  an 
atmosphere  of  Cl.  It  is  a  yellow,  fuming  liquid,  used  as  a  solvent 
for  S.  Several  oxychlorids  are  also  known. 

Bromin  in  contact  with  excess  of  S  forms  a  red  liquid  which 
consists  principally  of  S2Br2. 

The  iodid,  82X2,  is  obtained  by  heating  together  32  parts  S  and 
127  parts  I.  It  is  a  steel-gray,  crystalline  substance,  fusible  at  60° 
(140°F.),  insoluble  in  water;  and  has  been  used  in  medicine. 

Sulfur  Dioxid.  —  Sulfurous  oxid,  or  anhydrid  —  Acidum  sulfuro- 
sum  (U.  S.  ;  Br.)  —  862  —  Molecular  weighl=64:  —  Sp.  gr.  of  gas= 
2.213;  of  liquid=lA5—  Boils  at  —  10°  (14°  JP.);  solidifies  at  —75° 


Occurrence.  —  In  volcanic  gases  and  in  solution  in  some  mineral 
waters. 

Preparation.  —  (1)  By  burning  S  in  air  or  O. 

(2)  By  roasting  iron  pyrites  in  a  current  of  air. 

(3)  During  the  combustion  of  coal  or  coal-gas  containing  S  or 
its  compounds. 

(4)  By  heating  sulfuric  acid  with  copper:   2H2SO4H-Cu=CuSO4+ 
2H20-fSO2. 

(5)  By  heating  sulfuric  acid  with  charcoal:  2H2SO4+C=2SO2+ 
C02+2H20. 

(6)  By  decomposing  calcium  sulfite,  made  into  cubes  with  plaster 
of  Paris,  by  HC1,  at  the  ordinary  temperature. 

When  the  gas  is  to  be  used  as  a  disinfectant  it  is  usually  obtained 
by  reaction  (1);  in  sulfuric  acid  factories  (2)  is  used;  (3)  indicates 
the  method  in  which  atmospheric  862  is  chiefly  produced  ;  in  the 
laboratory  (4)  and  (6)  are  used  ;  (5)  is  the  process  directed  by  the 
U.  S.  and  Br.  Pharmacopoeias. 

Properties.  —  Physical.  —  A  colorless,  suffocating  gas,  having  a 
disagreeable  and  persistent  taste.  Very  soluble  in  H^O,  which  at  15° 
(59°  F.)  dissolves  about  40  times  its  volume  (see  below)  ;  also  soluble 
in  alcohol.  At  —  10°  (14°  F.)  it  forms  a  colorless,  mobile,  transpar- 
ent liquid,  by  whose  rapid  evaporation  a  cold  of  —  65°  (  —  85°  F.)  is 
obtained.  Liquid  SO2  packed  in  sealed  tins  or  in  syphons,  is  now 
a  commercial  article. 

Chemical.  Sulfur  dioxid  is  neither  combustible  nor  a  supporter  of 
combustion.  Heated  with  H  it  is  decomposed:  SO2+2H2=S-|-2H2O. 
With  nascent  hydrogen,  H2S  is  formed:  SO2+3H2==H2S+2H2O. 

Water  not  only  dissolves  the  gas,  but  combines  with  it  to  form  the 
true  sulfurous  acid,  HoSOs.  With  solutions  of  metallic  hydroxids  it 
forms  metallic  sulfites:  S02+KHO  =  KHS03;  or  SO2-h2KHO  — 


96  MANUAL    OF    CHEMISTRY 

K2gO3_|-H2o.  A  hydrate  having  the  composition  H2SO3,  8H2O  has 
been  obtained  as  a  crystalline  solid,  fusible  at  +4°  (39.2°  P.). 

Sulfur  dioxid  and  sulfureus  acid  solution  are  powerful  reducing 
agents,  being  themselves  oxidized  to  sulfuric  acid:  S02-hH2O-}-O= 
H2SO4;  or  H2S03+O=H2SO4.  It  reduces  nitric  acid  with  formation 
of  sulfuric  acid  and  nitrogen  tetroxid:  SO2+2HNO3r=H2SO4H-N2O4. 
It  decolorizes  organic  pigments,  without,  however,  destroying  the 
pigment,  whose  color  may  be  restored  by  an  alkali  or  a  stronger  acid. 
It  destroys  H2S,  acting,  in  this  instance,  not  as  a  reducing  but  as  an 
oxidizing  agent:  4SO2+3H2S=2H20+H2S506+S2.  With  Cl  it  com- 
bines directly  under  the  influence  of  sunlight  to  form  sulfuryl  chlorid 
(S02)"C12.  " 

Analytical  Characters.— (1)  Odor  of  burning  sulfur. 

(2)  Paper  moistened  with  starch  paste  and  iodic  acid  solution 
turns  blue  in  air  containing  1  in  3,000  of  S02. 

Sulfur  Trioxid — Sulfuric  oxid  or  anhydrid — SOs — Molecular  weight 
=80— Sp.  gr.  1.95. 

Preparation.— (1)  By  union  of  S02  and  0  at  250°-300°  (482°- 
572°  F.)  or  in  presence  of  spongy  platinum. 

(2)  By  heating  sulfuric  acid  in  presence  of  phosphoric  anhydrid: 
H2SO4+P205=S03+2HP03. 

(3)  By  heating  dry  sodium  pyrosulfate :   Na2S2O7=zNa2S04+S03. 

(4)  By  heating  pyrosulfuric  acid  below  100°  (212°F.),  in  a  retort 
fitted  with  a  receiver,  cooled  by  ice  and  salt:  H2S2O7~H2SO4-}-S03. 

Properties. — White,  silky,  odorless  crystals  which  give  off  white 
fumes  in  damp  air.  It  unites  with  H2O  with  a  hissing  sound,  and 
elevation  of  temperature,  to  form  sulfuric  acid.  When  dry  it  does 
not  redden  litmus. 

Sulfur  trioxid  exists  in  two  isomeric  (see  isomerism)  modifications, 
being  one  of  the  few  instances  of  isomerism  among  mineral  substances. 
The  a  modification,  liquid  at  summer  temperature,  solidifies  in  color- 
less prisms  at  16°  (60.8°  F.)  and  boils  at  46°  (114.8°  F.).  The  13 
isomere  is  a  white,  crystalline  solid  which  gradually  fuses  and  passes 
into  the  a  form  at  about  50°  (122°  F.) 


Oxacids  of  Sulfur. 

H28O2  Hyposulfurous  acid.  H2S2O7  Pyrosulfuric  acid. 

H28O3  Sulfurous  acid.  H2S2O0  Dithionic  acid. 

H2SO4  Sulfuric  acid.  H2S^OQ  Trithionic  acid. 

H2S2O8  Persulfuric  acid.  H2S4O0  Tetrathionia  acid. 

H28203  Thiosulfuric  acid.  H2S5O0  Pentathionic  acid. 


SULPHUR  97 

Hyposulfurous  Acid — £[2862— 66. — Hydrosulfurous  acid — Is  an 
unstable  body  known  only  in  solution,  obtained  by  the  action  of  zinc 
upon  solution  of  sulfurous  acid.  It  is  a  powerful  bleaching  and  de- 
oxidizing agent. 

Sulfurous  Acid — H^SOs — 82. — Although  sulfurous  acid  has  not 
been  isolated,  it,  in  all  probability,  exists  in  the  acid  solution,  formed 
when  sulfur  dioxid  is  dissolved  in  water:  SO2+H2O=SO3H2.  Its 
salts,  the  sulfites,  are  well  defined.  From  the  existence  of  certain 
organic  derivatives  (see  sulfonic  acids)  it  would  seem  that  two  iso- 
meric  modifications  of  the  acid  may  exist.  They  are  distinguished  as 
the  symmetrical,  in  which  the  S  atom  is  quadrivalent. 

0_SXOH 
°-S\OH' 

and  the  unsymmetrical ,  in  which  the  S  atom  is  hexavalent. 


O^°\OH' 

Sulfites. — The  sulfites  are  decomposed  by  the  stronger  acids,  with 
evolution  of  sulfur  dioxid.  Nitric  acid  oxidizes  them  to  sulfates. 
The  sulfites  of  the  alkali  metals  are  soluble,  and  are  active  reducing 
agents. 

The  analytical  characters  of  the  sulfites  are:  (1)  With  HC1  they 
give  off  SO2.  (2)  With  zinc  and  HC1  they  give  off  H2S.  (3)  With 
AgN03  they  form  a  white  ppt.,  soluble  in  excess  of  sulfite,  and 
depositing  metallic  Ag  when  the  mixture  is  boiled.  (4)  With  Ba- 
(NO3)2  they  form  a  white  ppt.,  soluble  in  HC1.  If  chlorin  water  be 
added  to  the  solution  so  formed  a  white  ppt.,  insoluble  in  acids,  is 
produced. 

Sulfuric  Acid — Oil  of  Vitriol  — Acidum  sulfuricum  (U.  S.;  Br.) 
— H2SO4— 98. 

Preparation.  —  (1)  By  the  union  of  sulfur  trioxid  and  water: 
SO3+H2O=H2SO4. 

(2)  By  the  oxidation  of  SO2  or  of  S  in  the  presence  of  water: 
2S02+2H2O-hO2=2H2S04;  or  S2+2H2O+302=2H2SO4. 

The  manufacture  of  H2SO4  may  be  said  to  be  the  basis  of  all 
chemical  industry,  as  there  are  but  few  processes  in  chemical  tech- 
nology into  some  part  of  which  it  does  not  enter.  The  method  fol- 
lowed at  present,  the  result  of  gradual  improvement,  may  be  divided 
into  two  stages  :  (1)  the  formation  of  a  dilute  acid;  (2)  the  con- 
centration of  this  product. 

The  first  part  is  carried  on  in  immense  chambers  of  timber,  lined 
with  lead,  and  furnishes  an  acid  having  a  sp.  gr.  of  1.55,  and  con- 
taining 65  per  cent  of  true  sulfuric  acid,  H2SC>4.  Into  these  cham- 
bers SO2,  obtained  by  burning  sulfur,  or  by  roasting  pyrites,  is 


98  MANUAL    OF    CHEMISTRY 

driven,  along  with  a  large  excess  of  air.  In  the  chambers  it  comes 
in  contact  with  nitric  acid,  at  the  expense  of  which  it  is  oxidized 
to  H2SO4,  while  nitrogen  tetroxid  (red  fumes)  is  formed:  S02+ 
2HNO-F=H2SO4+N2O4.  Were  this  the  only  reaction,  the  disposal 
of  the  red  fumes  would  present  a  serious  difficulty  and  the  amount 
of  nitric  acid  consumed  would  be  very  great.  A  second  reaction 
occurs  between  the  red  fumes  and  H2O,  which  is  injected  in  the 
form  of  steam,  by  which  nitric  acid  and  nitrogen  dioxid  are  pro- 
duced :  3N2O4-f  2H2O=4HNO3+2NO.  The  nitrogen  dioxid  in  turn 
combines  with  O  to  produce  the  tetroxid,  which  then  regenerates 
a  further  quantity  of  nitric  acid,  and  so  on.  This  series  of  reac- 
tions is  made  to  go  on  continuously,  the  nitric  acid  being  con- 
stantly regenerated,  and  acting  merely  as  a  carrier  of  O  from 
the  air  to  the  SO2,  in  such  manner  that  the  sum  of  the  reactions 
may  be  represented  by  the  following  equation:  2SO2-|-2H2O-|-O2= 
2H2SO4. 

The  acid  is  allowed  to  collect  in  the  chambers  until  it  has  the  sp. 
gr.  1.55,  when  it  is  drawn  off.  This  chamber  acid,  although  used  in 
a  few  industrial  processes,  is  not  yet  strong  enough  for  most  pur- 
poses. It  is  concentrated,  first,  by  evaporation  in  shallow  leaden 
pans,  until  its  sp.  gr.  reaches  1.746.  At  this  point  it  begins  to  act 
upon  the  lead,  and  is  transferred  to  platinum  stills,  where  the  con- 
centration is  completed. 

Varieties. — Sulfuric  acid  is  met  with  in  several  conditions  of 
concentration  and  purity: 

(1)  The  commercial  oil  of  vitriol,  largely  used  in  manufacturing 
processes,  is  a  more  or  less  deeply  colored,  oily  liquid,  varying  in  sp. 
gr.  from  1.833  to  1.842,  and  in  concentration  from  93  per  cent  to 
99%  per  cent  of  true  H2SO4. 

(2)  C.  P.   acid=Acidum   sulfuricum  (U.  S.;   Br.),   of   sp.  gr. 
1.84,  colorless  and  comparatively  pure  (see  below). 

(3)  Glacial  sulfuric  acid  is  a  hydrate  of  the  composition  H2SO4, 
H2O,  sometimes  called  bihijdrated  sulfuric  acid,  which  crystallizes  in 
rhombic  prisms,  fusible  at  +8.5°  (47.3°  F,)  when  an  acid  of  sp.  gr. 
1.788  is  cooled  to  that  temperature. 

(4)  Ac.  ftitlf.  Ml.  (U.  S.;  Br.)  is  a  dilute  acid  of  sp.  gr.  1.069 
and    containing    between   9   and  10    per   cent.   H2SO4   (U.   S.),   or 
of   sp.  gr.  1,094,  containing  between  12   and  13   per  cent.  H2SO4 
(Br.). 

Properties.— Physical—  A  colorless,  heavy,  oily  liquid;    sp    gr 
!    (53.7°F.)j   crystallizes  at  10.5°  (50.9°  F.);  boils  at  338° 
It  is  odorless,  intensely  acid  in  taste  and  reaction,  and 
highly  corrosive.     It  is  non-volatile  at  ordinary  temperatures.     Mix- 


SULFUR  99 

tures  of  the  acid  with  EbO  have  a  lower  boiling  point,  and  lower  sp. 
gr.  as  the  proportion  of  B^O  increases. 

Chemical. — At  a  red  heat  vapor  of  EbSCU  is  partly  dissociated 
into  SOs  and  EbO;  or,  in  the  presence  of  platinum,  into  S(>2,  EkO 
and  O.  When  heated  with  S,  C,  P,  Hg,  Cu,  or  Ag,  it  is  reduced 
with  formation  of  SO2. 

Sulfuric  acid  has  a  great  tendency  to  absorb  H20,  the  union  being 
attended  with  elevation  of  temperature,  increase  of  bulk,  and  diminu- 
tion of  sp.  gr.  of  the  acid,  and  contraction  of  volume  of  the  mixture. 
Three  parts,  by  weight,  of  acid  of  sp.  gr.  1.842,  when  mixed  with 
one  part  of  H2O  produce  an  elevation  of  temperature  to  130°  (266° 
F.),  and  the  resulting  mixture  occupies  a  volume  1-6  less  than  the 
sum  of  the  volumes  of  the  constituents.  Strong  H^SO*  is  a  good 
desiccator  of  air  or  gases.  It  should  not  be  left  exposed  in  uncovered 
vessels,  lest  by  increase  of  volume  it  overflow.  When  it  is  to  be 
diluted  with  B^O,  the  acid  should  be  added  to  the  EbO  in  a  vessel  of 
thin  glass,  to  avoid  the  projection  of  particles,  or  the  rupture  of  the 
vessel.  It  is  by  virtue  of  its  affinity  for  H2O  that  B^SO*  chars  or 
dehydrates  organic  substances.  Sulfuric  acid  is  a  powerful  dibasic 
acid. 

Impurities. — The  commercial  acid  is  so  impure  that  it  is  only  fit 
for  manufacturing  and  the  coarsest  chemical  uses.  The  so-called 
C.  P.  acid  may  further  contain:  Lead;  becomes  cloudy  when  mixed 
with  ten  times  its  volume  of  H2O,  if  the  quantity  of  Pb  be  sufficient. 
The  dilute  acid  gives  a  black  color  with  H2S.  Salts  ;  leave  a  fixed 
residue  when  the  acid  is  evaporated.  Sulfur  dioxid;  gives  off  B^S 
when  the  acid,  diluted  with  an  equal  volume  of  B^O,  comes  in  contact 
with  Zn.  Carbon  ;  communicates  a  brown  color  to  the  acid.  Arsenic; 
is  very  frequently  present.  When  the  acid  is  to  be  used  for  toxico- 
logical  analysis,  the  test  by  B^S  is  not  sufficient.  The  acid,  diluted 
with  an  equal  volume  of  H2O,  is  to  be  introduced  into  a  Marsh  appa- 
ratus, in  which  no  visible  stain  should  be  produced  during  an  hour. 
Oxids  of  nitrogen  are  almost  invariably  present;  they  communicate  a 
pink  or  red  color  to  pure  brucin. 

Sulfates. — Sulfuric  acid  being  dibasic,  there  exist  two  sulfates  of 
the  univalent  metals:  HKSO4  and  E^SOi,  and  but  one  sulfate  of 
each  bivalent  metal:  GaSO4.  The  sulfates  of  Ba,  Ca,  Sr,  and  Pb  are 
insoluble,  or  very  sparingly  soluble,  in  H2O.  Other  sulfates  are 
soluble  in  B^O,  but  all  are  insoluble  in  alcohol. 

Analytical  Characters. —  (1)  Barium  chlorid  (or  nitrate) ;  a  white 
ppt.,  insoluble  in  acids.  The  ppt.,  dried  and  heated  with  char- 
coal, forms  BaS,  which,  with  HC1,  gives  off  H2S.  (2)  Plumbic 
acetate  forms  a  white  ppt.,  insoluble  in  dilute  acids,  (3)  Cal- 


100  MANUAL    OF    CHEMISTRY 

cium  chlorid  forms  a  white  ppt.,  either  immediately,  or  upon  dilu- 
tion  with    two   volumes   of   alcohol;    insoluble    in    dilute    HC1    or 

HNO3. 

Toxicology. — Sulfuric  acid  is  an  active  corrosive,  and  may  be,  if 
taken  in  sufficient  quantity  in  a  highly  diluted  state,  a  true  poison. 
The  concentrated  acid  causes  death,  either  within  a  few  hours,  by 
corrosion  and  perforation  of  the  walls  of  the  stomach  and  oesoph- 
agus, or,  after  many  weeks,  by  starvation,  due  to  destruction  of 
the  gastric  mucous  membrane  and  closure  of  the  pyloric  orifice  of 
the  stomach. 

The  treatment  is  the  same  as  that  for  corrosion  by  HC1  (see 
page  86). 

Persulfuric  Acid. — H^Og— 194 — is  formed  by  the  electrolysis  of 
concentrated  sulfuric  acid:  2H2S04=H2S2O8+H2  ;  or  by  the  action  of 
hydrogen  peroxid  on  sulfuric  acid  :  2H2SO4+H2O2=H2S2O8+2H2O. 
It  crystallizes  at  0°  in  long,  transparent  needles.  The  corresponding 
anhydrid,  820?,  is  formed  by  the  action  of  high  tension  electric  cur- 
rents in  a  mixture  of  dry  862  and  O. 

Thiosulfuric  Acid. — Hijposulfurous  acid — 1128263 — 114 — may  be 
considered  as  sulfuric  acid,  H^SCU,  in  which  one  atom  of  oxygen  has 
been  replaced  by  one  of  sulfur.  The  acid  itself  has  not  been  iso- 
lated, being  decomposed,  on  liberation  from  the  thiosulfates,  into 
sulfur,  water,  and  sulfur  dioxid  :  H2S2O3==S-l-SO2-}-H2O. 

Pyrosulfuric  Acid. — Fuming  sulfuric  odd — Nordhausen  oil  of 
vitriol — D-isulfuric  hydrate — H2S2O7— Molecular  weight=178 — Sp.  gr. 
=1.9— Boils  at  52.2°  (126°  F). 

Preparation. — By  distilling  ferrous  sulfate;  and  purification  of 
the  product  by  repeated  crystallizations  and  fusions,  until  a  sub- 
stance fusing  at  35°  (95°  F.)  is  obtained. 

Properties. — The  commercial  Nordhausen  acid,  which  is  a  mix- 
ture of  H2S2O7  with  excess  of  SO3,  or  of  H2SO4,  is  a  brown,  oily 
liquid,  which  boils  below  100°  (212°  F-)  giving  off  SO3;  and  is  solid 
or  liquid  according  to  the  temperature.  It  is  used  chiefly  as  a  sol- 
vent for  indigo,  and  in  the  anilin  industry. 


SELENIUM   AND    TELLURIUM. 

Se— 78.5     Te— 126. 

These  are  rare  elements  which  form  compounds  similar  to  those 
of  sulfur.  Elementary  selenium  is  used  in  some  forms  of  electrical 
apparatus. 


NITROGEN 


101 


HI.  NITROGEN  GROUP. 

NITROGEN — PHOSPHORUS— ARSENIC — ANTIMONY. 

The  elements  of  this  group  are  trivalent  or  quinquivalent,  occa- 
sionally univalent.  With  hydrogen  they  form  non-acid  compounds, 
composed  of  one  volume  of  the  element  in  the  gaseous  state  with 
three  volumes  of  hydrogen,  the  union  being  attended  with  a  conden- 
sation of  volume  of  one -half. 

Bismuth,  frequently  classed  in  this  group,  is  excluded,  owing  to 
the  existence  of  the  nitrate  Bi(NOs)3.  The  relations  existing  between 
the  compounds  of  the  elements  of  this  group  are  shown  in  the  follow- 
ing table: 


NH3, 

N20, 

NO,             N203, 

N02, 

N205, 

— 

PH3, 

— 

P203, 

— 

P205, 

H3P02, 

AsH3, 

— 

As2O3 

i 

As2O5, 

— 

SbH3, 

— 

Sb203 

Sb204 

Sb205, 

— 

Hyd- 

Mon- 

Di-                  Tri- 

Tetr- 

Pent- 

Hypo-ous 

rid. 

oxid. 

oxid.               oxid. 

oxid. 

oxid. 

acid. 

— 

— 

HNO2, 

— 

— 

HN03, 

H3P03, 

H4P205, 

— 

H3P04, 

H4P207, 

HP03, 

H3AsO3, 

H4As2O5 

,        HAsO2, 

H3AsO4, 

H4As207, 

HAsO3, 

— 

— 

HSbO2, 

H3Sb04, 

H4Sb2O7, 

HSb03, 

-cms 

Pyro-ous 

Meta-ous 

-ic 

Pyro-ie 

Meta-ic 

acid. 

acid. 

acid. 

acid. 

acid. 

acid. 

NITROGEN. 

Azote— Sym~bol=N— Atomic  weight  =  l4:  (0  =  16:14.04;  H=l: 
13.93)—  Molecular  weight  =  2S—Sp.  gr. =0.9701—  One  litre  weighs 
1.254  grams — Name  from  viVpov^mtre,  y^e(r^=source  ;  or  from  a, 
privative  £«^=Jf/e — Discovered  ~by  Mayow  in  1669. 

Occurrence. — Free  in  atmospheric  air  and  in  volcanic  gases.  In 
combination  in  the  nitrates,  in  ammoniacal  compounds  and  in  a  great 
number  of  animal  and  vegetable  substances. 

Preparation.  — (1)  By  removal  of  O  from  atmospheric  air;  by 
burning  P  in  air,  or  by  passing  air  slowly  over  red-hot  copper.  It  is 
contaminated  with  CO2,  EbO,  etc. 

(2)  By  passing  Cl  through  excess  of  ammonium  hydroxid  solu- 
tion.    If  ammonia  be  not  maintained  in  excess,  the  Cl  reacts  with 
the  ammonium  chlorid  formed,   to  produce   the  explosive  nitrogen 
chlorid. 

(3)  By  heating  ammonium  nitrite  (NH4)NO2  :   or  a  mixture  of 
ammonium  chlorid  and  potassium  nitrite. 

Properties.  —  A    colorless,    odorless,    tasteless,    non- combustible 


102  MANUAL    OP    CHEMISTRY 

gas ;  not  a  supoorter  of  combustion  ;  very  sparingly  soluble  in 
water. 

It  is  very  slow  to  enter  into  combination,  and  most  of  its  com- 
pounds are  very  prone  to  decomposition,  which  may  occur  explo- 
sively or  slowly.  Nitrogen  combines  directly  with  0  under  the 
influence  of  electric  discharges  ;  and  with  H  under  like  conditions, 
and,  directly,  during  the  decomposition  of  nitrogenized  organic  sub- 
stances. It  combines  directly  with  magnesium,  boron,  vanadium, 
and  titanium 

Nitrogen  is  not  poisonous,  but  is  incapable  of  supporting  respi- 
ration. 

Argon. — A  substance  discovered  by  Rayleigh  and  Ramsay  in  1894 
in  the  atmosphere.  It  is  probably  an  element,  although  it  may  be  an 
allotropic  modification  of  nitrogen.  It  is  a  transparent,  odorless, 
tasteless  gas,  sp.  gr.=19.941.  At  the  ordinary  pressure  it  liquefies 
at — 186.9°  ( — 304.5°  F.),  forming  a  colorless  liquid  of  sp.  gr.  1.5. 
It  solidifies  at  —190°  (— 311.3°  F.).  It  is  sparingly  soluble  in 
water:  4.05  in  100.  No  compounds  of  argon  are  known. 

Atmospheric  Air. — The  alchemists  considered  air  as  an  element, 
until  Mayow,  in  1669,  demonstrated  its  complex  nature.  It  was  not, 
however,  until  1770  that  Priestley  repeated  the  work  of  Mayow;  and 
that  the  compound  nature  of  air,  and  the  characters  of  its  con- 
stituents were  made  generally  known  by  the  labors  (1770-1781)  of 
Priestley,  Rutherford,  Lavoisier,  and  Cavendish.  The  older  chemists 
used  the  terms  gas  and  air  as  synonymous. 

Composition. — Air  is  not  a  chemical  compound,  but  a  mechanical 
mixture  of  O  and  N,  with  smaller  quantities  of  other  gases.  Leaving 
out  of  consideration  vapor  of  water  and  small  quantities  of  other 
gases,  except  0.03  of  carbon  dioxid,  air  consists  of  20.95  O  and 
79.02  N  (including  argon),  by  volume  ;  or  about  23  O  and  77  N,  by 
weight ;  proportions  which  vary  but  very  slightly  at  different  times 
and  places;  the  extremes  of  the  proportion  of  O  found  having  been 
20.908  and  20.999. 

That  air  is  not  a  compound  is  shown  by  the  fact  that  the  pro- 
portion of  its  constituents  does  not  represent  a  relation  between 
their  atomic  weights,  or  between  any  multiples  thereof  ;  as  well  as 
by  the  solubility  of  air  in  water.  Were  it  a  compound  it  would 
have  a  definite  degree  of  solubility  of  its  own,  and  the  dissolved 
would  have  the  same  composition  as  when  free.  But  each  of 
its  constituents  dissolves  in  H2O  according  to  *  its  own  solubility, 
and  air  dissolved  in  H20  at  14.1°  (57. 4°  F.)  consists  of  N  and  O, 
not  in  the  proportion  given  above,  but  in  the  proportion  of  66.76 
to  33.24. 


NITKOGEN  103 

Besides  these  two  main  constituents,  air  contains  about  4-5 
thousandths  of  its  bulk  of  other  substances;  vapor  of  water,  carbon 
dioxid,  ammoniacal  compounds,  hydrocarbons,  ozone,  oxids  of  nitro- 
gen, and  solid  particles  held  in  suspension. 

Vapor  of  Water. — Atmospheric  moisture  is  either  visible,  as  in 
fogs  and  clouds,  when  it  is  in  the  form  of  a  finely  divided  liquid;  or 
invisible,  as  vapor  of  water.  The  amount  of  H2O  which  a  given 
volume  of  air  can  hold,  without  precipitation,  varies  according  to  the 
temperature  and  the  pressure.  It  happens  rarely  that  air  is  as  highly 
charged  with  moisture  as  it  is  capable  of  being  for  the  existing  tem- 
perature. The  fraction  of  saturation,  or  hygrometric  state,  or  rela- 
tive humidity  of  the  atmosphere  'is  the  percentage  of  that  quantity  of 
vapor  of  water  which  the  air  could  hold  at  the  existing  temperature 
and  pressure  which  it  actually  does  hold.  Thus  air  with  a  humidity 
of  100  is  saturated,  and  a  diminution  of  temperature  or  of  pressure 
would  cause  precipitation;  but  an  increase  of  temperature  or  of  pres- 
sure would  cause  a  diminution  of  humidity.  Ordinarily  air  contains 
from  66  to  70  per  cent,  of  its  possible  amount  of  moisture.  If  the 
quantity  be  less  than  this,  the  air  is  dry,  and  causes  a  parched  sensa- 
tion, and  the  sense  of  "stuffiness"  so  common  in  furnace -heated 
houses.  If  it  be  greater,  evaporation  from  the  skin  is  impeded,  and 
the  air  is  oppressive  if  warm. 

The  actual  amount  of  moisture  in  air  is  determined  by  passing  a 
known  volume  through  tubes  filled  with  calcium  chlorid;  whose 
increase  in  weight  represents  the  amount  of  H^O  in  the  volume  of  air 
used.  The  humidity  is  determined  by  instruments  called  hygrom- 
eters, hygroscopes  or  psychrometers. 

Carbon  Dioxid. — The  quantity  of  carbon  dioxid  in  free  air  varies 
from  3  to  6  parts  in  10,000  by  volume.  (See  Carbon  dioxid.) 

Ammoniacal  Compounds. — Carbonate,  nitrate,  and  nitrite  of 
ammonium  occur  in  small  quantity  (0.1  to  6.0  parts  per  million  of 
NHs)  in  air,  as  products  of  the  decomposition  of  nitrogenized  organic 
substances.  They  are  absorbed  and  assimilated  by  plants. 

Nitric  and  Nitrous  acids,  usually  in  combination  with  ammonium, 
are  produced  either  by  the  oxidation  of  combustible  substances  con- 
taining N,  or  by  direct  union  of  N  and  E^O  during  discharges  of 
atmospheric  electricity.  Rain-water,  falling  during  thunder-showers, 
has  been  found  to  contain  as  much  as  3.71  per  million  of  HNOa. 
(See  Hydrogen  peroxid,  p.  78). 

Sulfuric  and  Sulfurous  acids  occur,  in  combination  with  NELt, 
in  the  air  over  cities,  and  manufacturing  districts,  where  they  are 
produced  by  the  oxidation  of  S,  existing  in  coal  and  coal-gas. 

Hydrocarbons  have  been  detected  in  the  air  of  cities,  and  of 
swampy  places,  in  small  quantities. 


104  MANUAL   OP    CHEMISTRY 

Solid  particles  of  the  most  diverse  nature  are  always  present  in 
air  and  become  visible  in  a  beam  of  sunlight.  Sodium  chlorid  is 
almost  always  present,  always  in  the  neighborhood  of  salt  water. 
Air  contains  myriads  of  germs  of  vegetable  organisms,  mould,  etc., 
which  are  propagated  by  the  transportation  of  these  germs  by  air- 
currents. 

The  continued  inhalation  of  air  containing  large  quantities  of 
solid  particles  in  suspension  may  cause  severe  pulmonary  disorder,  by 
mere  mechanical  irritation,  and  apart  from  any  poisonous  quality  in 
the  substance;  such  is  the  case  with  the  air  of  carpeted  ball-rooms, 
and  of  the  workshops  of  certain  trades,  furniture  polishers,  metal 
filers,  etc. 

Compounds  of  Nitrogen  and  Hydrogen. — Three  are  known: 
Ammonia,  NHs;  Hydrazin,  N2EU;  and  Hydrazoic  acid,  N3H;  as 
well  as  salts  corresponding  to  two  hydroxids. 

Ammonia.  —  Hydrogen  nitrid  —  Volatile  alkali — NH3  — Molecular 
weight=l7—8p.  gr  =0.589  A— Liquefies  at  —40°  (—40°  F.)—  Boils 
at  —33.7°  (—28.7°  F.)—  Solidifies  at  —75°  (—103°  F.)— A  litre 
weighs  0.7655  gram. 

Preparation. — (1)  By  union  of  nascent  H  with  N. 

(2)  By  decomposition   of   organic   matter   containing   N,   either 
spontaneously  or  by  destructive  distillation. 

(3)  By  heating  solution  of  ammonium  hydroxid:  NH4HO=NH3+ 
H20. 

Properties. — Physical. — A  colorless  gas,  having  a  pungent  odor, 
and  an  acrid  taste.  It  is  very  soluble  in  H20,  1  volume  of  which  at 
0°  (32°  F.)  dissolves  1050  vols.  NH3,  and  at  15°  (59°  F.),  727  vols. 
NH3.  Alcohol  and  ether  also  dissolve  it  readily.  Liquid  ammonia  is 
a  colorless,  mobile  fluid,  used  in  ice  machines  for  producing  artificial 
cold,  the  liquid  absorbing  a  great  amount  of  heat  in  volatilizing. 

Chemical. — At  a  red  heat  ammonia  is  decomposed  into  a  mixture 
of  N  and  H,  occupying  double  the  volume  of  the  original  gas.  It  is 
similarly  decomposed  by  the  prolonged  passage  through  it  of  dis- 
charges of  electricity.  It  is  not  readily  combustible,  yet  it  burns  in  an 
atmosphere  of  O  with  a  yellowish  flame.  Mixtures  of  NH3  with  O, 
nitrogen  monoxid,  or  nitrogen  dioxid,  explode  on  contact  with  flame. 

The  solution  of  ammonia  in  H2O  constitutes  a  strongly  alkaline 
liquid,  known  as  aqua  ammoniac,  which  is  possessed  of  strongly  basic 
properties.  It  is  neutralized  by  acids  with  the  formation  of  crystal- 
line salts,  which  are  also  formed,  without  liberation  of  hydrogen,  by 
din-ct  union  of  gaseous  NH3  with  acid  vapors.  The  ammoniacal  salts 
and  the  alkaline  l»;is«-  in  aqua  ammonia?  are  compounds  of  a  radical, 
ammonium,  NH4,  which  forms  compounds  corresponding  to  those  of 


NITROGEN  105 

potassium  or  sodium.  The  compound  formed  by  the  union  of  am- 
monia and  water  is  ammonium  hydroxid,  NlLtHO  :  NHa+H2O= 
NEUHO  ;  and  that  formed  by  the  union  of  hydrochloric  acid  and 
ammonia  is  ammonium  chlorid,  NBUC1:  NH3+HC1=NH4C1. 

A  very  delicate  test  for  ammonia  is  Nessler's  reagent.  This  is 
made  by  dissolving  35  gm.  of  potassium  iodid  and  13  gm.  of  mercuric 
chlorid  in  800  cc.  H^O.  A  cold,  saturated  solution  of  mercuric 
chlorid  is  then  added,  drop  by  drop,  until  the  red  precipitate  formed 
no  longer  redissolves  on  agitation  ;  160  gm.  of  potassium  hydroxid 
are  then  dissolved  in  the  liquid,  which  is  finally  made  up  to  1000  cc. 
It  gives  a  yellow  color  with  a  mere  trace  of  NH3,  and  a  red -brown 
precipitate  with  a  larger  amount. 

Hydrazin  —  Diamid — H2N.NH2 — is  known  in  the  form  of  its 
hydroxid,  corresponding  to  ammonium  hydroxid,  in  the  form  of  its 
salts  and  in  numerous  organic  derivatives.  The  sulfate  is  produced 
by  the  action  of  £[2864  upon  triazoacetic  acid,  and  the  hydroxid  by 
decomposition  of  the  sulfate  by  caustic  soda.  The  hydroxid  is  an 
oily  liquid,  intensely  corrosive,  capable  of  attacking  glass.  It -com- 
bines with  acids  to  form  well-defined  salts,  and  precipitates  many 
metals  from  solutions  of  their  salts.  It  is  an  active  poison. 

Hydrazoic  Acid — Azoimid— N3H— is  a  substance  recently  ob- 
tained from  benzoyl-azoimid,  which,  although  containing  the  same 
elements  as  ammonia,  is  distinctly  acid  in  character.  It  is  a  colorless 
liquid,  boiling  at  37°  (98.6°  F.),  having  a  very  pungent  and  un- 
pleasant odor.  It  is  extremely  unstable  and  explodes  with  great 
violence.  It  reacts  with  metals,  oxids,  and  hydroxids,  as  does 
hydrochloric  acid,  to  form  nitrids,  which,  like  the  free  acid,  are  very 
explosive. 

Hydroxylamin — NEbHO— 33. — The  amins  and  amids  (q.  v.)  are 
compounds  derived  from  ammonia  by  the  substitution  of  radicals  for 
a  part  or  all  of  its  hydrogen.  This  substance,  which  is  intermediate 
in  composition  between  ammonia  and  ammonium  hydroxid,  may  be 
considered  as  ammonia,  one  of  whose  hydrogen  atoms  has  been  re- 
placed by  the  radical  hydroxyl,  HO.  It  is  obtained  in  aqueous  solu- 
tion by  the  union  of  nascent  hydrogen  with  nitrogen  dioxid:  NO+ 
H3— NH2HO ;  or  by  the  action  of  nascent  hydrogen  upon  nitric  acid : 
HNO3+3H2=2H2O+NH2HO.  Hydroxylamin  has  been  obtained  in 
colorless,  hygroscopic  crystals,  fusing  at  33°  (91.4°  F.).  by  syste- 
matic rectification  of  the  methyl  alcohol  solution  under  diminished 
pressure,  and  by  distillation  of  the  Zn  double  salt,  ZnCla,  2NH2OH 
with  anilin.  Its  aqueous  solution,  which  probably  contains  the  cor- 
responding hydroxid,  NH3O,  HO,  is  strongly  alkaline  and  behaves 
with  regard  to  acids  as  does  ammonium  hydroxid  solution,  forming 
salts  corresponding  to  those  of  ammonium.  Thus  hydroxyl  -  ammo- 


MANUAL    OP    CHEMISTRY 

nium  eWorld,  NH4OC1,  crystallizes  in  prisms  or  tables,  fusible  at 
100°  (212°  P.),  and  decomposed  into  HC1,  H2O  and  NH4C1  at  a 
slightly  higher  temperature.  It  is  a  very  powerful  reducing  agent. 

Hydroxylammonium  chlorid  has  been  used  in  the  treatment  of 
cutaneous  disorders.  It  is  an  actively  toxic  agent,  converting  oxy- 
hsemoglobin  into  methaemoglobin. 

Compounds  of  Nitrogen  with  the  Halogens.— Nitrogen  Chlorid 

NCla — 120.5— is  formed  by  the  action  of  excess  of  Cl  upon  NH3  or 

an  ammoniacal  compound.  It  is  an  oily,  light-yellow  liquid  ;  sp.  gr. 
1.653;  has  been  distilled  at  71°  (159.8  P.).  When  heated  to  96° 
(204.8°  P.),  when  subjected  to  concussion,  or  when  brought  in  con- 
tact with  phosphorus,  alkalies  or  greasy  matters,  it  is  decomposed, 
with  a  violent  explosion,  into  one  volume  N  and  three  volumes  Cl. 

Nitrogen  Bromid. — NBr3 — 254 — has  been  obtained  as  a  reddish- 
brown,  syrupy  liquid,  very  volatile,  and  resembling  the  chlorid  in  its 
properties,  by  the  action  of  potassium  bromid  upon  nitrogen  chlorid. 

Nitrogen  lodid. — NI3 — 395 — When  iodin  is  brought  in  contact 
with  ammonium  hydroxid  solution,  a  dark  brown  or  black  powder, 
highly  explosive  when  dried,  is  formed.  This  substance  varies  in 
composition  according  to  the  conditions  under  which  the  action 
occurs;  sometimes  the  iodid  alone  is  formed;  under  other  circum- 
stances it  is  mixed  with  compounds  containing  N,  I,  and  H. 

Oxids  of  Nitrogen. — Five  are  known,  forming  a  regular  series: 
N2O,  NO,  N2O3,  N20*,  N205.  Of  these  two,  the  trioxid,  N203,  and 
pentoxid,  N2O5,  are  anhydrids. 

Nitrogen  Monoxid. — Nitrous  oxid — Laughing  gas — Nitrogen  pro- 
toxid  —  N20—  Molecular  weight=44: — Sp.  gr.=  1.527  A — Fuses  at 
-100°  (— 148° F.)—  Boils  at  —87°  (— 124°  .F.)  —  Discovered  in  1776  by 
Priestley. 

Preparation. — By  heating  ammonium  nitrate:  (NH4)NO3=N2O+ 
2H2O.  To  obtain  a  pure  product  there  should  be  no  ammonium 
chlorid  present  (as  an  impurity  of  the  nitrate),  and  the  heat  should 
be  applied  gradually,  and  not  allowed  to  exceed  250°  (482°  P.),  and 
the  gas  formed  should  be  passed  through  wash -bottles  containing 
sodium  hydroxid  and  ferrous  sulfate. 

Properties. — Physical.  —  A  colorless,  odorless  gas,  having  a 
sweetish  taste;  soluble  in  H2O;  more  so  in  alcohol.  Under  a  pres- 
sure of  30  atmospheres,  at  0°  (32°  P.),  it  forms  a  colorless,  mobile 
liquid  which,  when  dissolved  in  carbon  disulfid  and  evaporated  in 

">,  produces  a  cold  of  —140°  (—220°  F.) . 

Chemical. — It  is  decomposed  by  a  red  heat  and  by  the  continuous 
passage  of  electric  sparks.  It  is  not  combustible,  but  is,  after 
oxygen,  the  best  supporter  of  combustion  known. 


NITROGEN  107 

Physiological. — Although,  owing  to  the  readiness  with  which 
N2O  is  decomposed  into  its  constituent  elements,  and  the  nature  and 
relative  proportions  of  these  elements,  it  is  capable  of  maintaining 
respiration  longer  than  any  gas  except  oxygen  or  air,  an  animal  will 
live  for  a  short  time  only  in  an  atmosphere  of  pure  nitrous  oxid. 
When  inhaled,  diluted  with  air,  it  produces  the  effects  first  observed 
by  Davy  in  1799:  first  an  exhilaration  of  spirits,  frequently  accom- 
panied by  laughter,  and  a  tendency  to  muscular  activity,  the  patient 
sometimes  becoming  aggressive;  afterward  there  is  complete  anes- 
thesia and  loss  of  consciousness.  It  has  been  much  used,  by  dentists 
especially,  as  an  anaesthetic  in  operations  of  short  duration,  and  in 
one  or  two  instances  anaesthesia  has  been  maintained  by  its  use  for 
nearly  an  hour. 

A  solution  in  water  under  pressure,  containing  five  volumes  of 
the  gas,  is  sometimes  used  for  internal  administration. 

Nitrogen  Dioxid. — Nitric  oxid — NO — Molecular  weigM=3Q — Sp. 
gr. =1.039  A — Discovered  by  Hales  in  1772. 

Preparation. — By  the  action  of  copper  on  moderately  diluted 
nitric  acid  in  the  cold:  3Cu+8HNO3=3Cu(NO3)2+4H2O+2NO;  the 
gas  being  collected  after  displacement  of  air  from  the  apparatus. 

Properties. — A  colorless  gas,  whose  odor  and  taste  are  unknown; 
very  sparingly  soluble  in  H2O;  more  soluble  in  alcohol.  The  sp.  gr.  of 
the  gas  has  been  determined  at — 100°  ( — 148°F.)  and  has  been  found 
to  be  same  as  at  the  ordinary  temperature.  This  fixes  the  molecular 
weight  at  30  and  gives  the  formula  NO,  which  is  difficult  to  reconcile 
with  the  theory  of  valence.  Were  the  formula  doubled  the  consti- 
tution of  this  gas  could  be  thus  expressed  :  O=N — N=O.  (See 
Nitrogen  tetroxid.) 

It  combines  with  O,  when  mixed  with  that  gas  or  with  air,  to 
form  the  reddish  brown  nitrogen  tetroxid.  It  is  absorbed  by  solu- 
tion of  ferrous  sulfate,  to  which  it  communicates  a  dark  brown  or 
black  color.  It  is  neither  combustible  nor  a  good  supporter  of  com- 
bustion, although  ignited  C  and  P  continue  to  burn  in  it,  and  the 
alkaline  metals,  when  heated  in  it,  combine  with  its  O  with  incan- 
descence. 

Nitrogen  Trioxid. — Nitrous  anhydrid — N2Os — 76 — Is  prepared  by 
the  direct  union  of  nitrogen  dioxid  and  oxygen  at  low  temperatures, 
or  by  decomposing  liquefied  nitrogen  tetroxid  with  a  small  quantity 
of  H2O  at  a  low  temperature :  4NO2+H2O=2HNO3+N203.  It  is  a 
dark  indigo-blue  liquid,  which,  boiling  at  about  0°  (32°  F.),  is  partly 
decomposed.  It  solidifies  at  —82°  (—115.6°  F.). 


108  MANUAL    OF    CHEMISTRY 

Nitrogen  Tetroxid.— Nitrogen  peroxid — Hyponitric  acid— Nitrous 
fumes  —  N2O4  —  Molecular  iveight=92— Boils  at  22°  (71.6°^.)- 
Solidifies  at  9°  (15.8°  F.). 

Preparation.— (1)  By  mixing  one  volume  O  with  two  volumes 
NO;  both  dry  and  ice-cold. 

(2)  By  heating  perfectly  dry  lead  nitrate,  O  being  also  produced: 
2Pb(NO3)2=2PbO+4NO2-f-O2. 

(3)  By  dropping  strong  nitric  acid  upon  a  red-hot  platinum  sur- 
face. 

Properties. — When  pure  and  dry,  it  is  an  orange -yellow  liquid  at 
the  ordinary  temperature;  the  color  being  darker  the  higher  the 
temperature;  the  gas  is  red-brown,  but  becomes  colorless  at  about 
500°  (932°  F.).  The  red  fumes,  which  are  produced  when  nitric 
acid  is  decomposed  by  starch  or  by  a  metal,  consist  of  N204,  mixed 
with  N203.  The  sp.  gr.  of  the  gas  varies  with  the  temperature  and 
pressure.  Values  varying  from  29.23  to  39.9  have  been  obtained 
(H=l).  The  molecular  formula,  NO2,  calls  for  sp.  gr.  23;  N204  for 
46.  These  variations  are  due  to  the  fact  that  the  gas  is  dissociated 
(p.  69)  at  comparatively  low  temperatures.  The  formula  N2O4  has 
been  fixed  as  the  correct  one  by  the  method  of  Eaoult  (see  p.  17). 
It  dissolves  in  nitric  acid,  forming  a  dark  yellow  liquid,  which  is  blue 
or  green  if  N203  be  also  present.  With  SO2  it  combines  to  form  a 
solid,  crystalline  compound,  which  is  sometimes  produced  in  the 
manufacture  of  H2SO4.  This  substance,  which  forms  the  lead  cham- 
ber crystals,  is  a  substituted  sulfurous  acid,  nitrosulfonic  acid, 
N02SO20H  (see  sulfonic  acids).  A  small  quantity  of  H20  decom- 
poses N2O4  into  HNOs  and  N2O3,  which  latter  colors  it  green  or  blue. 
A  larger  quantity  of  H2O  decomposes  it  into  HNO3  and  NO.  By 
bases  it  is  transformed  into  a  mixture  of  nitrite  and  nitrate: 
2N02-f2KHO==KN02-{-KN03+H2O. 

It  is  an  energetic  oxydant,  for  which  it  is  largely  used.  With 
certain  organic  substances  it  does  not  behave  as  an  oxydant,  but 
becomes  substituted  as  an  univalent  radical;  thus  with  benzene  it 
forms  nitro- benzene:  C6H5(N02). 

Toxicology. — The  brown  fumes  given  off  during  many  processes, 
in  which  nitric  acid  is  decomposed,  are  dangerous  to  life.  All  such 
operations,  when  carried  on  on  a  small  scale,  as  in  the  laboratory, 
should  be  conducted  under  a  hood  or  some  other  arrangement,  by 
which  the  fumes  are  carried  into  the  open  air.  When  in  industrial 
processes  the  volume  of  gas  formed  becomes  such  as  to  be  a  nuisance 
when  discharged  into  the  air,  it  should  be  utilized  in  the  manufacture 
<>f  II-jS<).,,  or  absorbed  by  H2O  or  an  alkaline  solution. 

An  atmosphere  contaminated  with  brown  fumes  is  more  dangerous 


NITROGEN  109 

than  one  containing  Cl,  as  the  presence  of  the  latter  is  more  imme- 
diately annoying.  At  first  there  is  only  coughing,  and  it  is  only  two 
to  four  hours  later  that  a  difficulty  in  breathing  is  felt,  death  occur- 
ring in  ten  to  fifteen  hours.  At  the  autopsy  the  lungs  are  found  to 
be  extensively  disorganized  and  filled  with  black  fluid. 

Even  air  containing  small  quantities  of  brown  fumes,  if  breathed 
for  a  long  time,  produces  chronic  disease  of  the  respiratory  organs. 
To  prevent  such  accidents,  thorough  ventilation  in  locations  where 
brown  fumes  are  liable  to  be  formed  is  imperative.  In  cases  of  spill- 
ing nitric  acid,  safety  is  to  be  sought  in  retreat  from  the  apartment 
until  the  fumes  have  been  replaced  by  pure  air  from  without. 

Nitrogen  Pentoxid. — Nitric  anhydrid — N2Os — Molecular  weight= 
108— Fuses  at  30°  (86°  F.)— Boils  at  47°  (116.6°  F.). 

Preparation. —  (1)  By  decomposing  dry  silver  nitrate  with  dry 
Cl  in  an  apparatus  entirely  of  glass :  4AgNO3+2Cl2=4AgCl-|- 
2N205+02. 

(2)  By  removing  water  from  fuming  nitric  acid  with  phosphorus 
pentoxid:  6HNO8+PiO5=2HsP<>4+3NiO*. 

Properties. — Prismatic  crystals  at  temperatures  above  30°  (86° 
F.).  It  is  very  unstable,  being  decomposed  by  a  heat  of  50°  (122° 
F.) ;  on  contact  with  H2O,  with  which  it  forms  nitric  acid;  and  even 
spontaneously.  Most  substances  which  combine  readily  with  O 
remove  that  element  from  N2Os. 

Nitrogen  Acids. — Three  are  known,  either  free  or  in  combination, 
corresponding  to  the  three  oxids  containing  uneven  numbers  of  O 
atoms: 

N2O  +H2O=2HNO  —  Hyponitrous  acid. 
N2O3+H2O=2HNO2— Nitrous  acid. 
N2O5+H2O=2HNO3— Nitric  acid. 

Hyponitrous  Acid — HNO  —  31  —  Known  only  in  combination. 
Sodium  hyponitrite  is  formed  by  the  action  of  sodium  upon  sodium 
nitrate,  or  nitrite:  NaNO3+4Na+2H2O=NaNO-f4NaHO.  Silver 
hyponitrite  is  formed  by  reduction  of  sodium  nitrate  by  nascent  H 
and  decomposition  with  silver  nitrate. 

Nitrous  Acid — Metanitrous  acid — HNO2 — 47 — has  not  been  iso- 
lated, although  its  salts,  the  nitrites,  are  well-defined  compounds: 
M/NO2  or  M"(NO2)2. 

The  nitrites  occur  in  nature,  in  small  quantity,  in  natural  waters, 
where  they  result  from  the  decomposition  of  nitrogenous  organic  sub- 
stances; also  in  saliva.  They  are  produced  by  heating  the  corre- 
sponding nitrate,  either  alone  or  in  the  presence  of  a  readily  oxidizable 
metal,  such  as  lead.  Solutions  of  the  nitrites  are  readily  decomposed 


HO  MANUAL    OF    CHEMISTRY 

by  the  mineral  acids,  with  evolution  of  brown  fumes.  They  take  up 
oxygen  readily  and  are  hence  used  as  reducing  agents.  Solutions  of 
potassium  permanganate  are  instantly  decolorized  by  nitrites.  A 
mixture  of  thin  starch  paste  and  zinc  iodid  solution  is  colored  blue 
by  nitrites,  which  decompose  the  iodid,  liberating  the  iodin.  A  solu- 
tion of  metaphenylendiamin,  in  the  presence  of  free  acid,  is  colored 
brown  by  very  minute  traces  of  a  nitrite,  the  color  being  due  to  the 
formation  of  triamido-azobenzene  (Bismark  brown). 

Nitric  Acid.  Aquafortis — Hydrogen  nitrate — Acidum  nitricum 
-U.  S.;  Br.— HNO3— 63. 

Preparation. — (1)  By  the  direct  union  of  its  constituent  elements 
under  the  influence  of  electric  discharges. 

(2)  By  the  decomposition  of  an  alkaline  nitrate  by  strong  H2S04. 
With  moderate  heat  a  portion  of  the  acid  is  liberated.  2NaNO3+ 
H2SO4=NaHSO4+NaNO3-j-HNO3,  and  at  a  higher  temperature  the 
remainder  is  given  off:  NaNO3+NaHSO4=Na2SO4+HNO3.  This  is 
the  reaction  used  in  the  manufacture  of  HNO3. 

Varieties. — Commercial — a  yellowish  liquid,  impure,  and  of  two 
degrees  of  concentration :  single  aquafortis  ;  sp.  gr.  about  1.25=39% 
HNO3;  and  double  aquafortis;  sp.  gr.  about  1.4=64%  HNO3. 
Fuming — a  reddish  yellow  liquid,  more  or  less  free  from  impurities; 
charged  with  oxids  of  nitrogen.  Sp.  gr.  about  1.5.  Used  as  an 
oxidizing  agent.  C.  P. — a  colorless  liquid,  sp.  gr.  1.522,  which 
should  respond  favorably  to  the  tests  given  below.  Acidum  nitri- 
cum, U.  S.;  Br.— a  colorless  acid,  of  sp.  gr.  1.42=70%  HNO3. 
Acidum  nitricum  dilutum,  U.  S.;  Br. — the  last  mentioned,  diluted 
with  H2O  to  sp.  gr.  1.059=10%  HNO3  (U.  S.),  or  to  sp.  gr.  1.101= 
17.44%  HNO3  (Br.). 

Properties. — Physical. — The  pure  acid  is  a  colorless  liquid:  sp. 
gr.  1.522;  boils  at  86°  (186.8°  F.);  solidifies  at  —40°  (— 40°F.); 
gives  off  white  fumes  in  damp  air;  and  has  a  strong  acid  taste  and 
reaction.  The  sp.  gr.  and  boiling  point  of  dilute  acids  vary  with  the 
concentration.  If  a  strong  acid  be  distilled,  the  boiling-point  grad- 
ually rises  from  86°  (186.8°  F.)  until  it  reaches  123°  (253.4°  F.), 
when  it  remains  constant,  the  sp.  gr.  of  distilled  and  distillate  being 
1.42=70%  HNO3.  If  a  weak  acid  be  taken  originally  the  boiling 
point  rises  until  it  becomes  stationary  at  the  same  point. 

Chemical. — When  exposed  to  air  and  light,  or  when  strongly 
heated,  HNO3  is  decomposed  into  N2O4;  H2O  and  O.  Nitric  acid  is 
a  valuable  oxydant;  it  converts  I,  P,  S,  C,  B,  and  Si  or  their  lower 
oxids  into  their  highest  oxids;  it  oxidizes  and  destroys  most  organic 
substances,  although  with  some  it  forms  products  of  substitution. 
Most  of  the  metals  dissolve  in  HNO3  as  nitrates,  a  portion  of  the 


NITROGEN  HI 

acid  being  at  the  same  time  decomposed  into  NO  and  H2O :  4HNO3+ 
3Ag=3AgNO3+NO-|-2H2O.  The  chemical  activity  of  HNO3  is  much 
reduced,  or  even  almost  arrested,'  when  the  intervention  of  nitrous 
acid  is  prevented  by  the  presence  of  carbamid.  The  so-called  "noble 
metals,"  gold  and  platinum,  are  not  dissolved  by  either  HNO3  or 
HC1,  but  dissolve  as  chlorids  in  a  mixture  of  the  two  acids,  called 
aqua  regia.  In  this  mixture  the  two  acids  mutually  decompose  each 
other  according  to  the  equations  :  HNO3+3HC1=2H2O+NOC1+C12 
and  2HNO3+6HC1=4H2O-|-2NOC12+C12  with  formation  of  nitrosyl 
chlorid,  NOC1  and  bichlorid,  NOC12,  and  nascent  Cl;  the  last  named 
combining  with  the  metal.  Iron  dissolves  easily  in  dilute  HNO3,  but 
if  dipped  into  the  concentrated  acid,  it  is  rendered  passive,  and  does 
not  dissolve  when  subsequently  brought  in  contact  with  the  dilute 
acid.  This  passive  condition  is  destroyed  by  a  temperature  of  40° 
(104°  F.)  or  by  contact  with  Pt,  Ag  or  Cu.  When  HNO3  is  decom- 
posed by  zinc  or  iron,  or  in  the  porous  cup  of  a  Grove  battery,  N203 
and  N2(>4  are  formed,  and  dissolve  in  the  acid,  which  is  colored  dark 
yellow,  blue  or  green. .  An  acid  so  charged  is  known  as  nitroso-nitric 
acid.  Nitric  acid  is  monobasic. 

Impurities. — Oxids  of  nitrogen  render  the  acid  yellow,  and  de- 
colorize potassium  permanganate  when  added  to  the  dilute  acid. 
Sulfuric  acid  produces  cloudiness  when  BaCl2  is  added  to  the  acid, 
diluted  with  two  volumes  of  H2O.  Chlorin,  iodin  cause  a  white  ppt. 
with  AgN03.  Iron  gives  a  red  color  when  the  diluted  acid  is  treated 
with  ammonium  thiocyanate.  Salts  leave  a  fixed  residue  when  the 
acid  is  evaporated  to  dryness  on  platinum. 

Nitrates. — The  nitrates  of  K  and  Na  occur  in  nature.  Nitrates 
are  formed  by  the  action  of  HNO3  on  the  metals,  or  on  their  oxids  or 
carbonates.  They  have  the  composition  M'NO3,  M"(N03)2  or  M" 
(N03)3,  except  certain  basic  salts,  such  as  the  sesquibasic  lead- 
nitrate,  Pb  (NO3)2,  2PbO.  With  the  exception  of  a  few  basic  salts, 
the  nitrates  are  all  soluble  in  water.  When  heated,  they  fuse  and  act 
as  powerful  oxidants.  They  are  decomposed  by  H2SO4  with  libera- 
tion of  HNO3. 

Analytical  Characters. —  (1)  Add  an  equal  volume  of  concen- 
trated H2S04,  cool,  and  float  on  the  surface  of  the  mixture  a  solution 
of  FeSO4.  The  lower  layer  becomes  gradually  colored  brown,  black 
or  purple,  beginning  at  the  top. 

(2)  Boil   in   a   test-tube  a   small   quantity  of   HC1,   containing 
enough  sulfindigotic  acid  to  communicate  a  blue  color,  add  the  sus- 
pected solution  and  boil  again ;   the  color  is  discharged. 

(3)  If  acid,  neutralize  with  KHO,  evaporate  to  dryness,  add  to 
the  residue  a  few  drops  of  H2SO4  and  a  crystal  of  brucin  (or  some 
sulfanilic  acid) ;  a  red  color  is  produced. 


112  MANUAL    OF    CHEMISTRY 

(4)  Add  H2SO4  and  Cu  to  the  suspected  liquid  and  boil,  brown 
fumes  appear  (best  visible  by  looking  into  the  mouth  of  the  test  tube) . 

(5)  A  solution  of  diphenylamin  in  concentrated  EbSO*  (.01  grm. 
in  100  cc.)  is  colored  blue  by  nitric  acid.     A  similar  color  is  produced 
by  other  oxidizing  agents. 

(6)  To  0.5  cc.  nitrate  solution  add  one  drop  aqueous  solution  of 
resorcinol  (10%),  and  1  drop  HC1  (15%),  and  float  on  the  surface  of 
2  cc.  concentrated  EbSC^;   a  purple -red  band. 

Toxicology. — Although  most  of  the  nitrates  are  poisonous  when 
taken  internally  in  sufficiently  large  doses,  their  action  seems  to  be 
due  rather  to  the  metal  than  to  the  acid  radical.  Nitric  acid  itself  is 
one  of  the  most  powerful  of  corrosives. 

Any  animal  tissue  with  which  the  concentrated  acid  comes  in  con- 
tact is  rapidly  disintegrated.  A  yellow  stain,  afterward  turning 
to  dirty  brownish,  or,  if  the  action  be  prolonged,  an  eschar,  is  formed. 
When  taken  internally,  its  action  is  the  same  as  upon  the  skin,  but 
owing  to  the  more  immediately  important  function  of  the  parts,  is 
followed  by  more  serious  results  (unless  a  large  cutaneous  surface  be 
destroyed) . 

The  symptoms  following  its  ingestion  are  the  same  as  those  pro- 
duced by  the  other  mineral  acids,  except  that  all  parts  with  which  the 
acid  has  come  in  contact,  including  vomited  shreds  of  mucous  mem- 
brane, are  colored  yellow.  The  treatment  is  the  same  as  that  indi- 
cated when  EbSO*  or  HC1  have  been  taken,  i.  e.,  neutralization  of 
the  corrosive  by  magnesia  or  soap,  and  dilution. 

PHOSPHORUS. 

Symbol=P— Atomic  weight=3l  (O— 16:31;  H— 1:30.74)—  Molec- 
ul<ir  weight=l24i  (P*) — Sp.gr.  of  vapor=4:.29Q4:  A — Name  from  <££>s 
=light,  <f>tpo>=I  bear — Discovered  by  Brandt  in  1669 — Phosphorus 
(U.  S.;  Br.). 

Occurrence. — Only  in  combination;  in  the  mineral  and  vegetable 
worlds  as  phosphates  of  Ca,  Mg,  Al,  Pb,  K,  Na.  In  the  animal 
kingdom  as  phosphates  of  Ca,  Mg,  K  and  Na,  and  in  organic  com- 
bination. 

Preparation. — From  bone -ash,  in  which  it  occurs  as  tricalcic 
phosphate.  Three  parts  of  bone -ash  are  digested  with  2  parts  of 
strong  EbSOj,  diluted  with  20  volumes  H^O,  when  insoluble  calcic 
sulfate  and  the  soluble  monocalcic  phosphate,  or  "superphosphate," 
are  formed:  Ca3(PO4)2+2H2SO4=H4Ca(PO4)2+2CaS04.  The  solu- 
tion of  superphosphate  is  filtered  off  and  evaporated,  the  residue  is 
mixed  with  about  one -fourth  its  weight  of  powdered  charcoal  and 


PHOSPHORUS  113 

sand,  and  the  mixture  heated,  first  to  redness,  finally  to  a  white  heat, 
in  earthenware  retorts,  whose  beaks  dip  under  water  in  suitable 
receivers.  During  the  first  part  of  the  heating  the  monocalcic  phos- 
phate is  converted  into  metaphosphate  :  CaH4(PO4)2=Ca(PO3)2+ 
2H20;  which  is  in  turn  reduced  by  the  charcoal,  with  formation  of 
carbon  monoxid  and  liberation  of  phosphorus,  while  the  calcium  is 
combined  as  silicate:  2Ca(PO3)2+2SiO2+5C2=2CaSiO3+10CO+P4. 

A  direct  electric  process  has,  in  great  part,  replaced  the  above 
industrially.  A  mixture  of  phosphate,  carbon  and  flux  is  heated  in  a 
closed  electric  furnace  provided  with  a  condenser.  The  process  is 
continuous  and  avoids  the  use  of  IbSO*. 

The  crude  product  is  purified  by  fusion,  first  under  a  solution  of 
bleaching  powder,  next  under  ammoniacal  EbO,  and  finally  under 
water  containing  a  small  quantity  of  H2SO4  and  potassium  dichromate. 
It  is  then  strained  through  leather  and  cast  into  sticks  under  warm 
H2O. 

Properties. — Physical. — Phosphorus  is  capable  of  existing  in  four 
allotropic  forms: 

(1)  Ordinary,  or  yellow  variety,  in  which  it  usually  occurs  in  com- 
merce.    This  is  a  yellowish,  translucid  solid,  of  the  consistency  of 
wax.     Below  0°  (32°  F.)  it  is  brittle;   it  fuses  at  44.3°  (111.7°  F.); 
and  boils  at  290°  (554°  F.)  in  an  atmosphere  not  capable  of  acting 
upon  it  chemically.     Its  vapor  is  colorless;   sp.  gr.=4.5A — 65  H  at 
1040°  (1940°  FJ.      It  volatilizes  below  its  boiling  point,  and  H2O 
boiled  upon  it  gives  off  steam  charged  with  its  vapor.     Exposed  to 
air  it  gives  off  white  fumes  and  produces  ozone.     It  is  luminous  in 
the  dark.     It  is  insoluble  in  H2O;   sparingly  soluble  in  alcohol,  more 
soluble  in  ether;   soluble  in  carbon  disulfid,  and  in  the  fixed  and 
volatile  oils.     It  crystallizes  on  evaporation  of  its  solutions  in  octa- 
hedrge  or  dodecahedree.     Sp.  gr.  1.83  at  10°  (50°  F.). 

(2)  White  phosphorus  is  formed  as  a  white,  opaque  pellicle  upon 
the  surface  of  the  ordinary  variety,  when  this  is  exposed  to  light 
under  aerated  H2O.     Sp.  gr,  1.515  at  15°  (59°  F.).     When  fused  it 
reproduces  ordinary  phosphorus  without  loss  of  weight. 

(3)  Black  variety  is  formed  when  ordinary  phosphorus  is  heated 
to  70°  (158°  F.)  and  suddenly  cooled. 

(4)  Red  variety  is  produced  from  the  ordinary  by  maintaining  it 
at  from  240°  (464°  F.)  to  280°  (536°  F.)  for  two  or  three  days,  in 
an  atmosphere  of  carbon  dioxid;  and,  after  cooling,  washing  out  the 
unaltered  yellow  phosphorus  with  carbon  disulfid.     It  is  also  formed 
upon  the  surface  of  the  yellow  variety,  when  it  is  exposed  to  direct 
sunlight. 

It  is  a  reddish,  odorless,  tasteless  solid,  which  does  not  fume  in 
air,  nor  dissolve  in  the  solvents  of  the  yellow  variety.  Sp.  gr.  2.1. 


MANUAL    OF    CHEMISTRY 

Heated  to  500°  (932°  F.)with  lead,  in  the  absence  of  air,  it  dissolves 
in  the  molten  metal,  from  which  it  separates  on  cooling  in  violet- 
black,  rhombohedral  crystals,  of  sp.  gr.  2.34.  If  prepared  at  ^250° 
(482°  F.)  it  fuses  below  that  temperature,  and  at  260°  (500°  F.) 
is  transformed  into  the  yellow  variety,  which  distils.  The  crystal- 
line product  does  not  fuse.  It  is  not  luminous  at  ordinary  tem- 
peratures. 

Chemical. — The  most  prominent  property  of  P  is  the  readiness 
with  which  it  combines  with  O.  The  yellow  variety  ignites  and 
burns  with  a  bright  flame  if  heated  in  air  to  60°  (140°F.),  or  if 
exposed  in  a  finely -divided  state  to  air  at  the  ordinary  temperature; 
with  formation  of  P2O3;  P2O5;  H3P03,  or  H3PO4,  according  as  O  is 
present  in  excess  or  not,  and  according  as  the  air  is  dry  or  moist. 
The  temperature  of  ignition  of  yellow  P  is  so  low  that  it  must  be 
preserved  under  boiled  water.  By  directing  a  current  of  O  upon  it, 
P  may  be  burned  under  H2O,  heated  above  45°  (113°  F.).  The  red 
variety  combines  with  0  much  less  readily,  and  may  be  kept  in  con- 
tact with  air  without  danger. 

The  luminous  appearance  of  yellow  P  is  said  to  be  due  to  the 
formation  of  ozone.  It  does  not  occur  in  pure  O  at  the  ordinary 
temperature,  nor  in  air  under  pressure,  nor  in  the  absence  of 
moisture,  nor  in  the  presence  of  minute  quantities  of  carbon  disulfid, 
oil  of  turpentine,  alcohol,  ether,  naphtha,  and  many  gases. 

Yellow  phosphorus  burns  in  Cl  with  formation  of  PC13  or  PCU, 
according  as  P  or  Cl  is  present  in  excess.  Both  yellow  and  red 
varieties  combine  directly  with  Cl,  Br,  and  I. 

Phosphorus  is  not  acted  on  by  HC1  or  cold  H2SO4.  Hot  H2SO4 
oxidizes  it  with  formation  of  phosphorous  acid  and  sulfur  dioxid: 
P4-f6H2SO4=:4H3PO3+6SO2.  Nitric  acid  oxidizes  it  violently  to 
phosphoric  acid  and  nitrogen  di-  and  tetr-oxids :  12HNO3+P4= 
4H3P04-f4N2O4-HNO. 

Phosphorus  is  a  reducing  agent.  When  immersed  in  cupric  sul- 
fate  solution,  it  becomes  covered  with  a  coating  of  metallic  copper.  In 
silver  nitrate  solution  it  produces  a  black  deposit  of  silver  phosphid. 

The  principal  uses  of  phosphorus  are  in  making  matches,  rat 
paste  and  phosphor  bronze. 

Toxicology. — The  red  variety  differs  from  the  other  allotropic 
forms  of  phosphorus  in  not  being  poisonous,  probably  owing  to  its 
insolubility,  and  in  being  little  liable  to  cause  injury  by  burning. 

The  burns  produced  by  yellow  phosphorus  are  more  serious  than 
a  like  destruction  of  cutaneous  surface  by  other  substances.  A  burn- 
ing fragment  of  P  adheres  tenaciously  to  the  skin,  into  which  it 
burrows.  One  of  the  products  of  the  combustion  is  metaphosphoric 
acid  (q.  v.)  which,  being  absorbed,  gives  rise  to  true  poisoning. 


PHOSPHORUS  115 

Burns  by  P  should  be  washed  immediately  with  dilute  javelle  water, 
liq.  sodae  chlorinatae,  or  solution  of  chlorid  of  lime.  Yellow  P  should 
never  be  allowed  to  come  in  contact  with  the  skin,  except  it  be  under 
cold  water. 

Yellow  P  is  one  of  the  most  insidious  of  poisons.  It  is  taken  or 
administered  usually  as  "ratsbane"  or  match -heads.  The  former  is 
frequently  starch  paste,  charged  with  phosphorus;  the  latter,  in  the 
ordinary  sulfur  match,  a  mixture  of  potassium  chlorate,  very  fine 
sand,  phosphorus,  and  a  coloring  matter.  The  symptoms  in  acute 
phosphorus -poisoning  appear  with  greater  or  less  rapidity,  according 
to  the  dose,  and  the  presence  or  absence  in  the  stomach  of  substances 
which  favor  its  absorption.  Their  appearance  may  be  delayed  for 
days,  but  as  a  rule  they  appear  within  a  few  hours.  A  disagreeable 
garlicky  taste  in  the  mouth,  and  heat  in  the  stomach  are  first  observed, 
the  latter  gradually  developing  into  a  burning  pain,  accompanied  by 
vomiting  of  dark -colored  matter,  which,  when  shaken  in  the  dark,  is 
phosphorescent;  low  temperature  and  dilatation  of  the  pupils.  In 
some  cases,  death  follows  at  this  point  suddenly,  without  the  appear- 
ance of  any  further  marked  symptoms.  Usually,  however,  the 
patient  rallies,  seems  to  be  doing  well,  until,  suddenly,  jaundice 
makes  its  appearance,  accompanied  by  retention  of  urine,  and  fre- 
quently delirium,  followed  by  coma  and  death. 

There  is  no  known  chemical  antidote  to  phosphorus.  The  treat- 
ment is,  therefore,  limited  to  the  removal  of  the  unabsorbed  portions 
of  the  poison  by  the  action  of  an  emetic,  zinc  or  copper  sulfate,  or 
apomorphin,  as  expeditiously  as  possible,  and  the  administration  of 
French  oil  of  turpentine — the  older  the  oil  the  better — as  a  physio- 
logical antidote.  The  use  of  fixed  oils  or  fats  is  to  be  avoided,  as 
they  favor  the  absorption  of  the  poison,  by  their  solvent  action. 
The  prognosis  is  very  unfavorable. 

Analysis. — When,  after  a  death  supposed  to  be  caused  by  phos- 
phorus, chemical  evidence  of  the  existence  of  the  poison  in  the  body, 
etc.,  is  desired,  the  investigation  must  be  made  as  soon  after  death 
as  possible,  for  the  reason  that  the  element  is  rapidly  oxidized,  and 
the  detection  of  the  higher  stages  of  oxidation  of  phosphorus  is  of  no 
value  as  evidence  of  the  administration  of  the  element,  because  they 
are  normal  constituents  of  the  body  and  of  the  food. 

The  detection  of  elementary  phosphorus  in  a  systematic  toxico- 
logical  analysis  is  connected  with  that  of  prussic  acid,  alcohol,  ether, 
chloroform,  and  other  volatile  poisons.  The  substances  under  ex- 
amination are  diluted  with  H2O,  acidulated  with  tartaric  acid  and 
heated  over  a  sand-bath  in  the  flask  a  (Fig.  24).  This  flask  is  con- 
nected with  a  CO2  generator,  c,  whose  stopcock  is  closed,  and  with  a 
Liebig's  condenser,  e,  which  is  in  darkness  (the  operation  is  best 


116 


MANUAL    OF    CHEMISTRY 


conducted  in  a  dark  room),  and  so  placed  as  to  deliver  the  distillate 
into  the  flask,/.  The  odor  of  the  distillate  is  noted.  In  the  presence 
of  P  it  is  usually  alliaceous.  The  condenser  is  also  observed.  If,  at 
the  point  of  greatest  condensation,  a  luminous  ring  be  observed  (in 
the  absence  of  all  reflections),  it  is  proof  positive  of  the  presence  of 
unoxidized  phosphorus.  The  absence,  however,  of  that  poison  is  not 


FIG.  24. 

to  be  inferred  from  the  absence  of  the  luminous  ring  (see  above) .  If 
this  fail  to  appear,  when  one -third  the  fluid  contents  of  the  flask  a 
have  distilled  over,  the  condenser  is  disconnected,  and  in  its  place  the 
absorbing  apparatus,  Fig.  25,  partly  filled  with  a  neutral  solution  of 
silver  nitrate,  is  adjusted  by  a  rubber  tube,  and  a  slow  and  con- 
stant stream  of  CO2  is  caused  to  traverse  the  apparatus  from  c 
(Fig.  24).  If,  during  continuation  of  the  distillation,  no  black 
deposit  be  formed  in  the  silver  solution,  the  absence  of  P  may  be 


PHOSPHORUS 


117 


FIG.  25. 


inferred.     If  a  black  deposit  be  formed,  it  must  be  further  examined 

to  determine  if  it  be  silver  phosphid.     For  this  purpose  the  apparatus 

shown    in   Fig.   26    is    used.     In   the   bottle   a 

hydrogen  is  generated  from  pure  Zn  and  H^SCU, 

the  gas  passing  through  the  drying -tube  5,  filled 

with  fragments  of  CaC^,  and  out  through  the 

platinum    tip  at    c;   d  and  e  are  pinch -cocks. 

When    the    apparatus    is    filled   with   H,   d   is 

closed  until  the  funnel -tube  /is  three-quarters 

filled  with  the  liquid  from  a  ;  then  e  is  closed 

and    d   opened,   and    the    black   silver  deposit, 

which  has  been  collected  on  a  filter  and  washed, 

is  thrown  into  /;  e  is  then  slightly  opened  and 

the  escaping  gas  ignited  at  c,  the  size  of  the 

flame   being   regulated    by   e.     If     the    deposit 

contain  P,  the  flame  will  have  a  green  color; 

and,  when  examined  with  the  spectroscope,  will 

give  the  spectrum   of  bright  bands    shown  in 

Pig.  27. 

Chronic  pliospliorus  poisoning,  or  Lucifer  disease,  occurs  among 
operatives  engaged  in  the  dipping,  drying,  and  packing  of  phos- 
phorus matches.  Those  engaged  in  the  manufacture  of  phosphorus 

itself  are  not  so  affected.  Sickly 
women  and  children  are  most 
subject  to  it.  The  cause  of  the 
disease  has  been  ascribed  to  the 
presence  of  arsenic,  and  to  the 
formation  of  oxids  of  phos- 
phorus, and  of  ozone.  The  pro- 
gress of  the  disorder  is  slow,  and 
its  culminating  manifestation  is 
the  destruction  of  one  or  both 
maxillae  by  necrosis. 

The  frequency  of  the  disease 
may  be  in  some  degree  dimin- 
ished by  thorough  ventilation  of 
the  shops,  by  frequent  washing 
of  the  face  and  mouth  with  a 
weak  solution  of  sodium  carbon- 
ate, by  exposing  oil  of  turpentine  in  saucers  in  the  workshops,  and 
particularly  by  keeping  the  teeth  in  repair.  None  of  these  methods, 
however,  effect  a  perfect  prevention,  which  can  only  be  attained  by 
the  substitution  of  the  red  variety  of  phosphorus  for  the  yellow 
in  this  industry. 


FIG.  26. 


118  MANUAL    OF    CHEMISTRY 

Hydrogen  Phosphids.  —  Gaseous  hydrogen  phosphid—  Phosphin 
—PhosphoHia,  rhoxplnuniH,  PHa—  34—  a  colorless  gas,  having  a  strong 
alliaceous  odor,  -which  is  obtained  pure  by  decomposing  phospho- 
nium  iodid,  PHJ,  with  H2O.  Mixed  with  H  and  vapor  of  P2H4,  it 
is  produced,  as  a  spontaneously  inflammable  gas,  by  the  action 
of  hot,  concentrated  solution  of  potassium  hydroxid  on  P,  or  by 
decomposition  of  calcium  phosphid  by  H2O.  It  is  highly  poison- 
ous. After  death,  the  blood  is  found  to  be  of  a  dark  violet  color, 
and  also  to  have,  in  a  great  measure,  lost  its  power  of  absorbing 
oxygen. 

Liquid  hydrogen  phosphid  —  P2H4—  66—  is  the  substance  whose 
vapor  communicates  to  PH3  its  property  of  igniting  on  contact  with 
air.  It  is  separated  by  passing  the  spontaneously  inflammable  PH3 
through  a  bulb  tube,  surrounded  by  a  freezing  mixture. 


FIG.  27. 

It  is  a  colorless,  heavy  liquid,  which  is  decomposed  by  exposure 
to  sunlight,  or  to  a  temperature  of  30°  (86°  F.). 

Solid  hydrogen  phosphid  —  P4H2  —  126  —  is  a  yellow  solid,  formed 
when  P2H4  is  decomposed  by  sunlight.  It  is  not  phosphorescent  and 
only  ignites  at  160°  (320°  F.). 

Compounds  of  Phosphorus  with  the  Halogens  —  Phosphorus 
Trichlorid  —  PCla  —  137.5  —  is  obtained  by  heating  P  in  a  limited  supply 
of  Cl.  It  is  a  colorless  liquid;  sp.  gr.  1.61;  has  an  irritating  odor; 
fumes  in  air;  boils  at  76°  (169°F.).  Water  decomposes  it  with 
formation  of  H3PO3  and  HC1. 

Phosphorus  Pentachlorid  —  PCls  —  208.5  —  is  formed  when  P  is 
burnt  in  excess  of  Cl.  It  is  a  light  yellow,  crystalline  solid  :  gives 
off  irritating  fumes;  and  is  decomposed  by  H2O. 

Phosphorus  Oxychlorid  —  POC13  —  153.5  —  is  formed  by  the  action 
of  a  limited  quantity  of  H20  on  the  pentachlorid:  PC15+H2O=POC13 
+2HC1.  It  is  a  colorless  liquid:  sp.  gr.  1.07;  boils  at  110°  (230°  F)  ; 
and  solidifies  at  —10°  (  +  14°  F.). 

With  bromin  P  forms  compounds  similar  in  composition  and 
properties  to  the  chlorin  compounds.  With  iodin  it  forms  two  com- 
pounds, P2I4  and  PI3.  With  fluorin  it  forms  two  compounds,  PF3 
and  PFs,  the  former  liquid,  the  second  gaseous. 


PHOSPHORUS  119 

Oxids  of  Phosphorus.  —  Two  are  known:   P203  and  P2(>5. 

Phosphorus  Trioxid.  —  Phosphorous  anhybrid,  Phosphorous  oxid  — 
p2O3  —  110  —  is  formed  when  P  is  burned  in  a  very  limited  supply  of 
perfectly  dry  air,  or  0.  It  is  white,  flocculent  solid,  which,  on  ex- 
posure to  air,  ignites  by  the  heat  developed  by  its  union  with  EkO  to 
form  phosphorous  acid. 

Phosphorus  Pentoxid.  —  Phosphoric  anhydrid,  Phosphoric  oxid. 
—  P2(>5  —  142  —  is  formed  when  P  is  burned  in  an  excess  of  dry  O.  It 
is  a  white,  flocculent  solid,  which  has  almost  as  great  a  tendency  to 
combine  with  H^O  as  has  P2O3.  It  absorbs  moisture  rapidly,  deli- 
quescing to  a  highly  acid  liquid,  containing,  not  phosphoric,  but 
metaphosphoric  acid.  It  is  used  as  a  drying  agent. 

Phosphorus  Acids.  —  Six  oxyacids  of  phosphorus  are  known  : 

/O—  H 

Hypophosphorous  acid  :    O=P  —  H 

\H 

/O—  H 

Phosphorous  acid:  O=P—  O  —  H 

\H 

/O—  H 

Phosphoric  acid  :  O=P—  O—  H 

\0-H 

/O—  H 
0=P—  O—  H 

Pyrophosphoric  acid  :  ^)O 

O=P—  O—  H 
\O—  H 

/O—  H 
Metaphosphoric  acid  :         O=P=O 


0=P-0-H 

Hypophosphoric  acid  :  \O 

P—  O—  H 
\O-H 

Only  those  H  atoms  which  are  connected  with  the  P  atoms 
through  O  atoms  are  basic.  Hence  H3PO2  is  monobasic;  H3PO3  is 
dibasic;  H3PO4  is  tribasic;  ELJ^O?  is  tetrabasic;  HPO2  is  monobasic, 
and  EL^Oe  is  tetrabasic.  Pyrophosphorous  acid,  O=P2=(OH)4  is 
only  known  in  an  organic  derivative,  acetyl-pyrophosphorous  acid  : 
O=P2=H.O(C2H3O).(OH)2;  and  metaphosphorous  acid,  O=P^ 
O.OH  is  unknown. 

Hypophosphorous  Acid.  —  H3PC>2  —  66  —  is  a  crystalline  solid,  or, 
more  usually,  a  strongly  acid,  colorless  syrup.  It  is  oxidized  by  air 
to  a  mixture  of  H3PO3  and  H3PO4. 


120  MANUAL    OF    CHEMISTRY 

The  hypophosphites,  as  well  as  the  free  acid,  are  powerful  reduc- 
ing agents. 

Phosphorous  Acid — HaPOs — 82 — is  formed  by  decomposition  of 
phosphorus  trichlorid  by  water:  PCl3+3H2O=H3P03+3HCl.  It  is  a 
highly  acid  syrup,  is  decomposed  by  heat,  and  is  a  strong  reducing 
agent. 

Phosphoric  Acid—Orthophosphoric  acid — Common  or  tribasic  phos- 
phoric acid — Acidum  phosphoricum  (U.S.;  Br.) — H3PO4 — 98 — does 
not  occur  free  in  nature,  but  is  widely  disseminated  in  combination, 
in  the  phosphates,  in  the  three  kingdoms  of  nature. 

It  is  prepared:  (1)  By  converting  bone  phosphate,  Ca3(P04)2  into 
the  corresponding  lead  or  barium  salt,  Pb3(PC>4)2  or  Ba3(PO4)2,  and 
decomposing  the  former  by  H2S,  or  the  latter  by  H2SO4.  (2)  By 
oxidizing  P  by  dilute  HN03,  aided  by  heat.  The  operation  should  be 
conducted  with  caution,  and  heat  gradually  applied  by  the  sand  bath. 
It  is  best  to  use  red  phosphorus.  This  is  the  process  directed  by  the 
U.  S.  and  Br.  Pharm. 

The  concentrated  acid  is  a  colorless,  transparent,  syrupy  liquid; 
still  containing  H2O,  which  it  gives  off  on  exposure  over  H2SO4,  leaving 
the  pure  acid,  in  transparent,  deliquescent,  prismatic  crystals.  It  is 
decomposed  by  heat  to  form,  first,  pyrophosphoric  acid,  then  meta- 
phosphoric  acid.  It  is  tribasic. 

If  made  from  arsenical  phosphorus,  and  commercial  phosphorus 
is  arsenical  unless  made  by  the  electrolytic  method  (p.  113),  it  is  con- 
taminated with  arsenic  acid,  whose  presence  may  be  recognized  by 
Marsh's  test  (q.  v.).  The  acid  should  not  respond  to  the  indigo  and 
ferrous  sulfate  tests  for  HN03. 

Ortho-acids  are  those  in  which  the  number  of  hydroxyls  equals 
the  valence  of  the  acidulous  elements.  Thus  orthophosphoric  acid 
is  P(OH)5;  orthocarbonic  acid,  C(OH)4.  Sometimes,  as  in  the 
case  of  phosphorus,  when  this  acid  is  not  known,  that  in  which 
the  number  of  hydroxyls  most  nearly  equals  the  valence  of  the 
acidulous  element  is,  improperly,  called  the  ortho-acid. 

Phosphates.— Phosphoric  acid  being  tribasic,  the  phosphates  have 
the  composition  MXH2PO4;  M/2HPO4;  M/3PO4;  M"(H2PO4)2; 
M//2(HP04)2;  M"3(P04)2;  M//M/P04;  and  M/X/PO4.  The  mono- 
metallic salts  are  all  soluble  and  are  strongly  acid.  Of  the  dimetallic 
salts,  those  of  the  alkali  metals  only  are  soluble  and  their  solutions 
are  faintly  alkaline;  the  others  are  unstable,  and  exhibit  a  marked 
tendency  to  transformation  into  monometallic  or  trimetallic  salts. 
The  normal  phosphates  of  the  alkali  metals  are  the  only  soluble  tri- 
in.-tallic  phosphates.  Their  solutions  are  strongly  alkaline,  and  they 
are  decomposed  even  by  weak  acids: 


PHOSPHORUS  121 

Na3PO4        +        CO3H2        =        HNa2PO4        -f        HNaCO3 

Trisodie  Carbonic  Disodie  Monosodic 

phosphate.  acid.  phosphate.  carbonate. 

All  the  monometallic  phosphates,  except  those  of  the  alkali  metals, 
are  decomposed  by  ammonium  hydroxid,  with  precipitation  -of  the 
corresponding  trimetallic  salt. 

Analytical  Characters. — (1)  With  ammoniacal  solution  of  silver 
nitrate,  a  yellow  precipitate.  (2)  With  solution  of  ammonium 
molybdate  in  HNO3,  a  yellow  precipitate.  (3)  With  magnesia  mix- 
ture,* a  white,  crystalline  precipitate,  soluble  in  acids,  insoluble  in 
ammonium  hydroxid. 

Pyrophosphoric  Acid — ILJr^OT — 178. — When  phosphoric  acid  (or 
hydro-disodic  phosphate)  is  maintained  at  213°  (415.4°  F.),  two  of 
its  molecules  unite,  with  the  loss  of  the  elements  of  a  molecule  of 
water:  2H3PO4::::=H4P207+H2O,  to  form  pyrophosphoric  acid. 

Metaphosphoric  Acid — Glacial  phosphoric  acid — HPO3 — 80 — is 
formed  by  heating  H3PO4  or  H4P2O7  to  near  redness:  H3P04=HPO3 
+ H2O;  or  H4P207=2HPO3+H2O.  It  is  usually  obtained  from  bone 
phosphate;  this  is  first  converted  into  ammonium  phosphate,  which 
is  then  subjected  to  a  red  heat. 

It  is  a  white,  glassy,  transparent  solid,  odorless  and  acid  in  taste 
and  reaction.  Slowly  deliquescent  in  air,  it  is  very  soluble  in  H2O, 
although  the  solution  takes  place  slowly,  and  is  accompanied  by  a 
peculiar  crackling  sound.  In  constitution  and  basicity  it  resembles 
HN03. 

The'metaphosphates  are  capable  of  existing  in  five  polymeric  modi- 
fications (see  polymerism) :  Mono-  di-  tri-  tetra-  and  hexmeta-  phos- 
phates: M'PO3;  M/2(PO3)2  and  M"(P03)2;  M/3(PO3)3;  M/4(PO3)4 
and  M"2(P03)4;  and  M/6(PO3)6. 

Hypophosphoric  Acid — H4P2O6 — 162. — When  phosphorus  is  ex- 
posed to  moist  air  a  strongly  acid  liquid  is  slowly  formed,  known  as 
phosphatic  acid.  This  is  a  mixture  of  phosphorous,  phosphoric  and 
hypophosphoric  acids.  The  last  named  is  separated  from  the  others 
by  taking  advantage  of  the  sparing  solubility  of  its  acid  sodium  salt; 
this  is  then  converted  into  the  lead  salt,  which  is  decomposed  by  H2S, 
and  the  liberated  acid  concentrated.  It  has  not  been  crystallized. 
It  is  quite  stable  at  the  ordinary  temperature,  but  slowly  decomposes 
to  a  mixture  of  phosphorous  and  pyrophosphoric  acids.  It  is  quadri- 
basic.  It  may  be  considered  as  formed  by  the  union  of  a  mole- 
cule of  phosphoric  acid  and  one  of  phosphorous  acid,  with  loss  of 
H2O:  H3PO4+H3P03==H4P2O6+H2O. 

Action  of  the  Phosphates  on  the  Economy. — The  salts  of  phos- 

*  Made  by  dissolving  11  pts.  crystallized  magnesium  chlorid  and  28  pts.  ammonium  chlorid  in 
130  pts.  water,  adding  70  pts.  dilute  ammonium  hydroxid  (sp.  gr.  0.96)  and  filtering  after  two  days. 


MANUAL    OP    CHEMISTRY 

phoric  acid  are  important  constituents  of  animal  tissues,  and  give 
rise,  when  taken  internally,  in  reasonable  doses,  to  no  untoward 
symptoms.  The  acid  itself  may  act  deleteriously,  by  virtue  of  its  acid 
reaction.  Meta-  and  pyrophosphoric  acids,  even  when  taken  in  the 
form  of  neutral  salts,  have  a  distinct  action  (the  pyro  being  the  more 
active)  upon  the  motor  ganglia  of  the  heart,  producing  diminution  of 
the  blood-pressure,  and,  in  comparatively  small  doses,  death  from 
cessation  of  the  heart's  action. 


ARSENIC. 

Symbol=As— Atomic  weight=75  (O=16:75;  H— 1:74.4)—  Molec- 
ular u'<'ig1it='3QO  (As4) — Sp.  gr.  of  solid;  crystalline=5.75,  amorphous 
=4.71;  ofvapor=W.6  A  at  860°  (1580°  F.)— Name  from  dpo-m/coi^r 
orpimmt. 

Occurrence. — Free  in  small  quantity;  in  combination  as  arsenids 
of  Fe,  Co,  and  Ni,  but  most  abundantly  in  the  sulfids,  orpiment  and 
realgar,  and  in  arsenical  iron  pyrites,  or  mispickel. 

Preparation. — (l)By  heating  mispickel  in  clay  cylinders,  which 
communicate  with  sheet  iron  condensing  tubes. 

(2)  By  heating  a  mixture  of  arsenic  trioxid  and  charcoal;  and 
purifying  the  product  by  resublimation. 

Properties. — Physical. — A  brittle,  crystalline,  steel-gray  solid, 
having  a  metallic  luster,  or  a  dull,  black,  amorphous  powder.  At  the 
ordinary  pressure,  and  without  contact*  of  air,  it  volatilizes  without 
fusion  at  180°  (356°  F.) ;  under  strong  pressure  it  fuses  at  a  dull  red 
heat.  Its  vgpor  is  yellowish,  and  has  the  odor  of  garlic.  It  is  insol- 
uble in  H20,  and  in  other  liquids  unless  chemically  altered. 

Chemical. — Heated  in  air  it  is  converted  into  the  trioxid,  and 
ignites  somewhat  below  a  red  heat.  In  O  it  burns  with  a  brilliant, 
bluish -white  light.  In  dry  air  it  is  not  altered,  but  in  the  presence 
of  moisture  its  surface  becomes  tarnished  by  oxidation.  In  H2O  it  is 
slowly  oxidized,  a  portion  of  the  oxid  dissolving  in  the  water.  It 
combines  readily  with  Cl,  Br,  I,  and  8,  and  with  most  of  the  metals. 
With  H  it  only  combines  when  that  element  is  in  the  nascent  state. 
Warm,  concentrated  H^SCU  is  decomposed  by  As,  with  formation  of 
S(>2,  As2Oa,  and  EkO.  Nitric  acid  is  readily  decomposed,  giving  up 
its  O  to  the  formation  of  arsenic  acid.  With  hot  HC1,  arsenic  tri- 
chlorid  is  formed.  When  fused  with  potassium  hydroxid,  arsenic  is 
oxidized,  H  is  given  off,  and  a  mixture  of  potassium  arsenite  and 
arsenid  remains,  which  by  greater  heat  is  converted  into  arsenic, 
which  volatilizes,  and  potassium  arsenate,  which  remains. 

Elementary  arsenic  enters  into  the  composition  of  fly  poison  and  of 


ARSENIC  123 

shot,  and  is  used  in  the  manufacture  of  certain  pigments  and  fire- 
works. 

Compounds  of  Arsenic  and  Hydrogen.  —  Two  are  known  :    the 
solid  As2H  (?)  and  the  gaseous, 


Hydrogen  Arsenid  —  Arsin  —  Arseniuretted  or  arsenetted  hydrogen 
—  Arsenia  —  Arsenamin  —  AsELs  —  Molecular  weight=78  —  Sp.  gr.=2.695 
A—  Liquefies  at  —40°  (—40°  F.). 

Formation.  —  (1)  By  the  action  of  H2O  upon  an  alloy,  obtained 
by  fusing  together  native  sulfid  of  antimony,  2  pts.  ;  cream  of  tartar, 
2  pts.;  and  arsenic  trioxid,  1  pt. 

(2)  By  the  action  of  dilute  HC1  or  IUSO4  upon  the  arsenids  of 
Zn  and  Sn.     This  is  practically  the  same  as  3,   nascent  hydrogen 
being  formed  bv  the  action  of  the  metal  upon  the  acid. 

(3)  Whenever  a  reducible  compound  of  arsenic  is  in  presence  of 
nascent  hydrogen.     (See  Marsh  test.) 

(4)  By  the  action  of  EbO  upon  the  arseuids  of  the  alkali  metals. 

(5)  By  the  combined  action  of  air,  moisture  and  organic  matter 
upon  arsenical  pigments. 

(6)  By  the  action  of  hot  solution  of  potassium^  hydroxid  upon 
reducible  compounds  of  As  in  the  presence  of  zinc. 

Properties.  —  Physical.  —  A  colorless  gas  ;  having  a  strong  allia- 
ceous odor;  soluble  in  5  vols.  of  EbO,  free  from  air. 

Chemical.  —  It  is  neutral  in  reaction.  In  contact  with  air  and 
moisture  its  H  is  slowly  removed  by  oxidation,  and  elementary  As 
deposited.  It  is  also  decomposed  into  its  elements  by  the  passage 
through  it  of  luminous  electric  discharges;  and  when  subjected  to  a 
red  heat.  It  is  acted  on  by  dry  O  at  ordinary  temperatures  with  the 
formation  of  a  black  deposit,  which  is  at  first  solid  hydrogen  arsenid, 
later  elementary  As.  A  mixture  of  AsHs  and  O,  containing  3  vols. 
O  and  2  vols.  AsHs,  explodes  when  heated,  forming  As2Oa  and  H2O. 
If  the  proportion  of  O  be  less,  elementary  As  is  deposited. 

The  gas  burns  with  a  greenish  flame,  from  which  a  white  cloud  of 
arsenic  trioxid  arises.  A  cold  surface,  held  above  the  flame,  becomes 
coated  with  a  white,  crystalline  deposit  of  the  oxid.  If  the  flame  be 
cooled,  by  the  introduction  of  a  cold  surface  into  it,  the  H  alone  is 
oxidized,  and  elementary  As  is  deposited.  Chlorin  decomposes  the 
gas  explosively,  with  formation  of  HC1  and  arsenic,  or  arsenic  tri- 
chlorid,  if  the  01  be  in  excess.  In  the  presence  of  EbO,  arsenous  and 
arsenic  acids  are  formed.  Bromin  and  iodin  behave  similarly,  but 
with  less  violence. 

All  oxidizing  agents  decompose  it  readily;  EbO  and  arsenic  tri- 
oxid being  formed  by  the  less  active  oxidants,  and  EbO  and  arsenic 
acid  by  the  more  active.  Solid  potassium  hydroxid  decomposes  the 


124  MANUAL    OF    CHEMISTRY 

gas  partially,  and  becomes  coated  with  a  dark  deposit,  which  seems 
to  be  elementary  arsenic.  Solutions  of  the  alkaline  hydroxids  absorb 
and  decompose  it;  H  is  given  off  and  an  alkaline  arsenite  remains 
in  the  solution.  Many  metals,  when  heated  in  H3As,  decompose  it 
with  formation  of  a  metallic  arsenid  and  liberation  of  hydrogen. 
Solution  of  silver  nitrate  is  reduced  by  it ;  elementary  silver  is  de- 
posited, and  the  solution  contains  silver  arsenite. 

Although  H2S  and  H3As  decompose  each  other  to  a  great  extent, 
with  formation  of  arsenic  trisulfid,  in  the  presence  of  air,  the  two 
gases  do  not  act  upon  each  other  at  the  ordinary  temperature,  even 
in  the  direct  sunlight,  either  dry  or  in  the  presence  of  EbO,  when  air 
is  absent.  Hence  in  making  H2S  for  use  in  toxicological  analysis, 
materials  free  from  As  must  be  used  ;  or  the  EbS  must  be  purified  as 
described  on  p.  92. 

Compounds  of  Arsenic  with  the  Halogens. — Arsenic  Trifluorid 

— AsF3— 132.— A  colorless,  fuming  liquid,  boiling  at  63°  (145°F.), 
obtained  by  distilling  a  mixture  of  As2O3,  EbSCX,  and  fluorspar.  It 
attacks  glass. 

ArsenicTrichlorid — AsCl3 — 181.5. — Obtained  by  distilling  a  mix- 
ture of  As2O3,  H2SO4,  and  NaCl,  using  a  well-cooled  receiver. 

It  is  a  colorless  liquid,  boils  at  134°  (273°F.),  fumes  when  ex- 
posed to  the  air,  and  volatilizes  readily  at  temperatures  below  its 
boiling  point.  Its  formation  must  be  avoided  in  processes  for  the 
chemico- legal  detection  of  arsenic,  lest  it  be  volatilized  and  lost.  It 
is  formed  by  the  action  of  HC1,  even  when  comparatively  dilute,  upon 
AsoOa  at  the  temperature  of  the  water-bath;  but,  if  potassium  chlo- 
rate be  added,  the  trioxid  is  oxidized  to  arsenic  acid,  and  the  forma- 
tion of  the  chlorid  thus  prevented.  Arsenic  trioxid,  when  fused  with 
sodium  nitrate,  is  converted  into  sodium  arsenate,  which  is  not 
volatile.  If,  however,  small  quantities  of  chlorids  be  present,  AsCl3 
is  formed.  It  is  highly  poisonous. 

Arsenic  Tribromid — AsBr3 — 315. — Obtained  by  adding  powdered 
As  to  Br,  and  distilling  the  product  at  220°  (428°  F.).  A  solid, 
colorless,  crystalline  body,  fuses  at  20°-25°  (68°-77°  F.),  boils  at 
220°  (428°  F.),  and  is  decomposed  by  H2O. 

ArsenicTriiodid — Arsenii  iodidum,  U.  S. — AsI3 — 456.— Formed 
by  adding  As  to  a  solution  of  I  in  carbon  disulfid,  or  by  fusing  to- 
gether As  and  I  in  proper  proportions.  A  brick -red  solid,  fusible 
and  volatile.  Soluble  in  a  large  quantity  of  H2O.  Decomposed  by 
B  small  quantity  of  H2O  into  HI,  As2O3,  H2O  and  a  residue  of  Asia. 

Compounds  of  Arsenic  and  Oxygen.  —  Two  are  known  :  As2O3 
and  As2O5. 

Probably  the  gray  substance  formed  by  the  action  of  moist  air  on 
elementary  arsenic  is  a  lower  oxid. 


ARSENIC  125 

Arsenic  Trioxid  —  Arsenous  anhydrid  —  Arsenous  oxid  —  White 
arsenic — Arsenic — Arsenous  acid — Acidum  arseniosum,  U.  S.;  Br. 

— As203— 198. 

Preparation. — (1)  By  roasting  the  native  sulfids  of  arsenic  in  a 
current  of  air. 

(2)  By  burning  arsenic  in  air  or  oxygen. 

Properties. — Physical. — It  occurs  in  three  forms:  crystallized  or 
"powdered"  vitreous,  and  porcelainous .  When  freshly  fused,  it  ap- 
pears in  colorless  or  faintly  yellow,  translucent,  vitreous  masses, 
having  no  visible  crystalline  structure.  Shortly,  however,  these 
masses  become  opaque  upon  the  surface,  and  present  the  appearance 
of  porcelain.  This  change  slowly  progresses  toward  the  center  of  the 
mass,  which,  however,  remains  vitreous  for  a  long  time.  When 
arsenic  trioxid 'is  sublimed,  if  the  vapors  be  condensed  upon  a  cool 
surface,  it  is  deposited  in  the  form  of  brilliant  octahedral  crystals, 
which  are  larger  and  more  perfect  the  nearer  the  temperature  of  the 
condensing  surface  is  to  180°  (356°  F.).  When  sublimed  under 
slightly  increased  pressure,  or  in  an  atmosphere  of  862,  right  rhom- 
bic prisms  occur  among  the  octahedra.  It  is  therefore  dimorphous. 
The  crystalline  variety  may  be  converted  into  the  vitreous,  by  keeping 
it  for  some  time  at  a  temperature  near  its  point  of  volatilization. 

Although  As2O3  is  heavier  than  water,  when  thrown  upon  that 
liquid  a  large  part  of  the  crystalline  powder  floats,  and  a  part  of  that 
which  sinks  at  first  subsequently  rises.  This  is  due  to  adhesion  of 
air  to  the  particles  of  the  solid.  The  same  phenomenon  renders  the 
solution  of  As2O3  in  water  slow  and  irregular.  The  vitreous  variety 
is  more  readily  soluble  than  the  crystalline.  The  taste  of  arsenic 
trioxid  in  solution  is  very  faint,  at  first  sweetish,  afterward  very 
slightly  metallic.  The  solid  is  almost  tasteless.  It  is  odorless.  In 
aqueous  solution  it  has  a  faintly  acid  reaction.  The  sp.  gr.  of  the 
vitreous  variety  is  3.785;  that  of  the  crystalline,  3.689. 

Chemical. — Its  solutions  are  acid  in  reaction,  and  probably  contain 
the  true  arsenous  acid,  H3AsO3.  They  are  neutralized  by  bases,  with 
formation  of  arsenites.  Solutions  of  sodium,  or  potassium  hydroxid, 
or  carbonate  dissolve  it,  with  formation  of  the  corresponding  arsenite. 
It  is  readily  reduced,  with  separation  of  As,  when  heated  with  hydro- 
gen, carbon,  and  potassium  cyanid,  and  at  lower  temperatures  by 
more  active  reducing  agents.  Oxidizing  agents,  such  as  HNO3,  the 
chlorin  oxyacids,  chromic  acid,  convert  it  into  arsenic  pentoxid  or 
arsenic  acid.  Its  solution,  acidulated  with  HC1  and  boiled  in  presence 
of  copper,  deposits  on  the  metal  a  gray  film,  composed  of  an  alloy  of 
Cu  and  As. 

Arsenic  Pentoxid — Arsenic  anhydrid — Arsenic  oxid — As2Os — 230 
— is  obtained  by  heating  arsenic  acid  to  redness.  It  is  a  white,  amor- 


1-jr,  MANUAL    OF    CHEMISTRY 

phous  solid,  which,  when  exposed  to  the  air,  slowly  absorbs  moisture. 
It  is  fusil.  1«>  at  a  dull  red  heat,  and  at  a  slightly  higher  temperature 
decomposes  to  As2O3  and  O.  It  dissolves  slowly  in  H2O,  forming 
arsenic  acid,  HaAsO.*. 

Arsenic  Acids.  —  The  oxyacids  of  arsenic  form  a  series,  corre- 
sponding to  that  of  the  oxyacids  of  phosphorus,  except  that  the  hypo- 
arsenous  and  hypoarsenic  acids  are  unknown,  and  pyro-  and  metar- 
senous  acids  are  known  in  their  salts: 

/O—  H 

/O—  H          Arsenic  acid:        O=As—  O—  H 
Areenous  acid:        O=As-O-H  \O—  H 


/0-H 

/A  -°-H  O=AS-O-H 

.,       /AS—  O—  H          Pyroarsenic  acid  :  ;O 

Pyroarsenous  acid  :  O  n     pr  / 

\As~~  0=As-0-H 

\0-H 

Metarsenous  acid:  O=  As—  O—H  /O—H 

Metarsenic  acid:  O=As=O    . 

Arsenous  Acid.  —  HsAsOs  —  126  —  exists  in  aqueous  solutions  of 
the  trioxid,  although  it  has  not  been  separated.  Corresponding  to 
it  are  important  salts,  called  arsenites,  which  have  the  general  for- 
mula? HM'2As03,  HM^AsOs,  H4M//(AsO3)2.  Pyro-  and  metarsenous 
acids  are  only  known  in  combination. 

Arsenic  Acid  —  Ortlioarsenic  acid  —  HsAsC^  —  142  —  is  obtained  by 
oxidizing  As2Os  with  HNOs  in  the  presence  of  H2O:  As2O3+2H2O+ 
2HNO3=2H3AsO4+N2O3.  A  similar  oxidation  is  also  effected  by  Cl, 
aqua  regia,  and  other  oxidants. 

A  syrupy,  colorless,  strongly  acid  solution  is  thus  obtained,  which, 
at  15°  (59°  F.),  becomes  semi-solid,  from  the  formation  of  transpar- 
ent crystals,  containing  1  Aq.  These  crystals,  which  are  very  soluble 
and  deliquescent,  lose  their  Aq  at  100°  (212°  F.),  and  form  a 
white,  pasty  mass,  composed  of  minute  white,  anhydrous  needles. 
At  higher  temperatures  it  is  converted  into  EUA^O?,  HAsOs,  and 
As205.  In  presence  of  nascent  H  it  is  decomposed  into  H2O  and 
AsH3.  It  is  reducible  to  H3AsO3  by  SO2. 

The  action  of  H2S  upon  acid  solutions  of  arsenic  acid,  or  of  the 
arsenates,  varies  with  the  rapidity  of  the  action  and  the  temperature 
at  which  it  occurs.  With  a  slow  current  of  H2S,  at  a  low  tempera- 
ture, no  precipitate  is  formed,  and  the  solution  remains  colorless. 
Under  these  conditions  thioxyarsenic  acid,  H3AsO3S,  is  formed: 
II  AsOi-hH2S=H:{AsSO3+H2O.  By  a  further  action  of  H2S,  arsenic 
pentasulfid  is  formed:  2H3AsO3S+3H2S=As2S5+6H2O.  If  the  cur- 
rent of  H2S  be  very  slow,  the  thioxyarsenic  acid  produced  is  decom- 
posed according  to  the  equation:  2H3AsO3S=As2O3+3H2O+S2  and 


ARSENIC  127 


the  precipitate  then  produced  consists  of  a  mixture  of  As2S3, 
andS. 

Like  phosphoric  acid,  arsenic  acid  is  tribasic;  and  the  arsenates 
resemble  the  phosphates  in  composition,  and  in  many  of  their  chemi- 
cal and  physical  properties. 

Pyroarsenic  Acid  —  ELp^O?  —  266.  —  Arsenic  acid,  when  heated  to 
160°  (320°F.),  is  converted  into  compact  masses  of  pyroarsenic  acid: 
2H3AsO4=H4As2O7-hH2O.  It  is  very  prone  to  revert  to  arsenic  acid, 
by  taking  up  water. 

Metarsenic  Acid—  HAsO3—  124.—  At  200°-206°  (392°-403°  F.) 
H4AS2O?  gradually  loses  JEbO  to  form  metarsenic  acid:  H4AS2O7- 
=2HAsO3+H2O.  It  forms  white,  pearly  crystals,  which  dissolve 
readily  in  H^O,  with  regeneration  of  HsAsCU.  It  is  monobasic. 

Compounds  of  Arsenic  and  Sulfur.  —  Arsenic  Disiilfid  —  Red 
sulfid  of  arsenic  —  Realgar  —  Red  orpiment  —  Ruby  sulfur  —  Sandarach  — 
As2S2  —  214  —  occurs  in  nature,  in  translucent,  ruby  -red  crystals.  It 
is  also  prepared  by  heating  a  mixture  of  As2Os  and  S.  As  so  ob- 
tained it  appears  in  brick  -red  masses. 

It  is  fusible,  insoluble  in  H2O,  but  soluble  in  solutions  of  the 
alkaline  sulfids,  and  in  boiling  solution  of  potassium  hydroxid. 

Arsenic  trisulfid  —  Orpiment  —  Auripigmentum  —  Yellow  sulfid  of 
arsenic  —  King's  yelloiv  —  As2$3  —  246  —  occurs  in  nature  in  brilliant 
golden  yellow  flakes.  Obtained  by  passing  IbS  through  an  acid 
solution  of  As2Os;  or  by  heating  a  mixture  of  As  and  S,  or  of  As20s 
and  S  in  equivalent  proportions. 

When  formed  by  precipitation,  it  is  a  lemon  -yellow  powder;  or  in 
orange  -yellow,  crystalline  masses,  when  prepared  by  sublimation. 
Almost  insoluble  in  cold  EbO,  but  sufficiently  soluble  in  hot  EbO  to 
communicate  to  it  a  distinct  yellow  color.  By  continued  boiling  with 
IbO  it  is  decomposed  into  EbS  and  As2Os.  Insoluble  in  dilute  HC1; 
but  readily  soluble  in  solutions  of  the  alkaline  hydroxids,  carbonates, 
and  sulfids.  It  volatilizes  when  heated. 

Nitric  acid  oxidizes  it,  forming  HsAsC^  and  EbSCU.  A  mixture 
of  HC1  and  potassium  chlorate  has  the  same  effect.  It  corresponds 
in  constitution  to  As2Os,  and  like  it,  may  be  regarded  as  an  an- 
hydrid,  for  although  thioarsenous  acid,  HsAsSs,  has  not  been  sepa- 
rated, the  thioarseni-tes,  pyro-  and  meta-thioarsenites  are  well- 
characterized  compounds. 

Arsenic  Pentasulfid  —  As2$5  —  310  —  is  formed  by  fusing  a  mixture 
of  As2$3  and  S  in  proper  proportions,  and,  by  the  prolonged  action 
of  EbS,  at  low  temperatures,  upon  solutions  of  the  arsenates. 

It  is  a  yellow,  fusible  solid,  capable  of  sublimation  in  absence  of 
air.  There  exist  well-defined  thioarsenates,  pyro  -and  meta-thio- 
arsenates. 


128  MANUAL    OF    CHEMISTRY 

Action  of  Arsenical  Compounds  Upon  the  Animal  Economy. 

The  poisonous  nature  of  many  of  the  arsenical  compounds  has 
been  known  from  remote  antiquity,  and  it  is  probable  that  more 
murders  have  been  committed  by  their  use  than  by  that  of  all  other 
toxic  substances  combined.  Even  at  the  present  time  —  notwith- 
standing the  fact  that,  suspicion  once  aroused,  the  detection  of 
arsenic  in  the  dead  body  is  certain  and  comparatively  easy — crim- 
inal arsenical  poisoning  is  still  quite  common,  especially  in  rural 
districts. 

The  poison  is  usually  taken  by  the  mouth,  but  it  has  also  been 
introduced  by  other  channels;  the  skin,  either  uninjured  or  abraded, 
the  rectum,  vagina,  and  male  urethra.  The  forms  in  which  it  has 
been  taken  are:  (1)  Elementary  arsenic,  which  is  not  poisonous  so 
long  as  it  remains  such.  In  contact  with  water,  or  with  the  saliva, 
however,  it  is  converted  into  an  oxid,  ~"hich  is  then  dissolved,  and, 
being  capable  of  absorption,  produces  th^  characteristic  effects  of  the 
arsenical  compounds.  Certain  fly-papers  and  fly -poisons  contain  As, 
a  portion  of  which  has  been  oxidized  by  the  action  of  air  and 
moisture.  (2)  Hydrogen  arsenid,  the  most  actively  poisonous  of 
the  inorganic  compounds  of  arsenic,  has  been  the  cause  of  several 
accidental  deaths,  among  others,  that  of  the  chemist  Gehlen,  who 
died  in  consequence  of  having  inhaled  the  gas  while  experimenting 
with  it.  In  other  cases  death  has  followed  the  inhalation  of  hy- 
drogen, made  from  zinc  and  sulfuric  acid  contaminated  with  arsenic. 
(3)  Arsenic  trioxid  is  the  compound  most  frequently  used  by  crim- 
inals. It  has  been  given  by  every  channel  of  entrance  to  the  circu- 
lation; in  some  instances  concealed  with  great  art,  in  others  merely 
held  in  suspension  by  stirring  in  a  transparent  fluid,  given  to  an 
intoxicated  person.  If  the  poison  have  been  in  quantity,  and  undis- 
solved,  it  may  be  found  in  the  stomach  after  death,  in  the  form  of 
eight -sided  crystals,  more  or  less  worn  by  the  action  of  the  solvents 
with  which  it  has  come  in  contact.  (4)  Potassium  arsenite,  the 
active  substance  in  "Fowler's  solution,"  although  largely  used  by  the 
laity  in  malarial  districts  as  an  ague -cure,  has,  so  far  as  the  records 
show,  produced  but  few  cases  of  fatal  poisoning.  (5)  Sodium 
arsenite  is  sometimes  used  to  clean  metal  vessels,  a  practice  whose 
natural  results  are  exemplified  in  the  death  of  an  individual  who 
drank  beer  from  a  pewter  mug  so  cleaned;  and  in  the  serious  illness 
of  340  children  in  an  English  institution,  in  which  this  material  had 
been  used  for  cleaning  the  water-boiler.  (6)  Arsenic  acid  and 
arsenates. — The  acid  itself  has,  so  far  as  we  know,  been  directly  fatal 
to  no  one.  The  cases  of  death  and  illness,  however,  which  have  been 
put  to  the  account  of  the  red  anilin  dyes,  are  not  due  to  them  directly, 


ARSENIC  129 

but  to  arsenical  residues  remaining  in  them  as  the  result  of  defective 
processes  of  manufacture.  (7)  Sulfids  of  arsenic. — Poisoning  by 
these  is  generally  due  to  the  use  of  orpiment,  introduced  into  articles 
of  food  as  a  coloring  matter,  by  a  combination  of  fraud  and  stu- 
pidity, in  mistake  for  turmeric.  (8)  The  arsenical  greens. — Scheele's 
green,  or  cupric  arsenite,  and  Schweinfurth  green,  or  cupric  aceto- 
metarsenite  (the  latter  commonly  known  in  the  United  States  as 
Paris  green,  a  name  applied  in  Europe  to  one  of  the  anilin  pig- 
ments). These  substances,  although  rarely  administered  with  mur- 
derous intent,  have  been  the  cause  of  death  in  a  great  number  *  of 
cases. 

The  arsenical  pigments  may  also  produce  disastrous  results  by 
"accident;"  by  being  incorporated  in  ornamental  pieces  of  confection- 
ery; by  being  used  in  the  coloring  of  textile  fabrics,  from  which  they 
may  be  easily  rubbed  off;  from  their  use  for  the  destruction  of  insects, 
and  by  being  used  in  the  manufacture  of  wall-paper.  Many  instances 
of  chronic  or  subacute  arsenical  poisoning  have  resulted  from  inhab- 
iting rooms  hung  with  paper  whose  whites,  reds,  or  greens  were  pro- 
duced by  arsenical  pigments.  From  such  paper  the  poison  is  dissemi- 
nated in  the  atmosphere  of  the  room  in  two  ways:  either  as  an 
impalpable  powder,  mechanically  detached  from  the  paper  and  floating 
in  the  air,  or  by  their  decomposition,  and  the  consequent  diffusion  of 
volatile  arsenical  compounds  in  the  air. 

The  treatment  in  acute  arsenical  poisoning  is  the  same,  whatever 
may  be  the  form  in  which  the  poison  has  been  taken,  if  it  have  been 
taken  by  the  mouth.  The  first  indication  is  the  removal  of  any  unab- 
sorbed  poison  from  the  alimentary  canal.  If  vomiting  have  not 
occurred  from  the  effects  of  the  toxic,  it  should  be  induced  by  the 
administration  of  zinc  sulfate,  or  by  mechanical  means.  When  the 
stomach  has  been  emptied,  the  chemical  antidote  is  to  be  administered, 
with  a  view  to  the  transformation,  in  the  stomach,  of  any  remaining 
arsenical  compound  into  the  insoluble,  and  therefore  innocuous,  fer- 
rous arsenate.  To  prepare  the  antidote,  a  solution  of  ferric  sulfate, 
Liq.  ferri  tersulphatis  (U.  S.)=Liq.  ferri  persulphatis  (Br)  is  to  be 
diluted  with  three  volumes  of  water,  and  treated  with  aqua  ammonias 
in  slight  excess.  The  precipitate  formed  is  then  collected  upon  a 
muslin  filter,  and  washed  with  water  until  the  washings  are  nearly 
tasteless.  The  contents  of  the  filter — Ferri  oxidum  hydratum  (U.  S.), 
Ferri  peroxidum  Mtmidum  (Br.)  are  to  be  given  moist,  in  repeated 
doses  of  one  to  two  teaspoonsful,  until  an  amount  of  the  hydrate 
equal  to  20  times  the  weight  of  white  arsenic  taken  has  been  ad- 
ministered. Dialyzed  iron  may  be  given  while  the  hydrate  is  in 
preparation,  or  whenever  the  materials  for  its  preparation  are  not 
obtainable. 
9 


130  MANUAL    OF    CHEMISTRY 

Precautions  to  be  taken  by  the  Physician  in  cases  of   Suspected 

Poisoning. 

It  will  rarely  happen  that  in  a  case  of  suspected  homicidal  poison- 
ing by  arsenic,  or  by  other  poisons,  the  physician  in  charge  will  be 
willing  or  competent  to  conduct  the  chemical  analysis,  upon  which, 
probably,  the  conviction  or  acquittal  of  the  accused  will  mainly  depend. 
Upon  his  knowledge  and  care,  however,  the  success  or  futility  of  the 
chemist's  labors  depends  in  a  great  measure. 

It  is,  as  a  rule,  the  physician  who  first  suspects  foul  play;  and 
while  it  is  undoubtedly  his  duty  to  avoid  any  public  manifestation  of 
his  suspicion,  it  is  as  certainly  his  duty  toward  his  patient  and  toward 
the  community,  to  satisfy  himself  as  to  the  truth  or  falsity  of  his 
suspicion  by  the  application  of  a  simple  test  to  the  excreta  of  the 
patient  during  life,  the  result  of  which  may  enable  him  to  prevent  a 
crime,  or,  failing  that,  take  the  first  step  toward  the  punishment  of 
the  criminal. 

In  a  case  in  which,  from  the  symptoms,  the  physician  suspects 
poisoning  by  any  substance,  he  should  himself  test  the  urine  or 
fa3ces,  or  both,  and  govern  his  treatment  and  his  actions  toward  the 
patient,  and  those  surrounding  the  patient,  by  the  results  of  his 
examination.  Should  the  case  terminate  fatally,  he  should  at  once 
communicate  his  suspicions  to  the  prosecuting  officer,  and  require  a 
post-mortem  investigation,  which  should,  if  at  all  possible,  be  con- 
ducted in  the  presence  of  the  chemist  who  is  to  conduct  the  analysis. 
For,  be  the  physician  as  skilled  as  he  may,  there  are  odors  and 
appearances,  observable  in  many  cases  at  the  opening  of  the  body, 
full  of  meaning  to  the  toxicological  chemist,  which  are  ephemeral, 
and  whose  bearing  upon  the  case  is  not  readily  recognized  by  those 
not  thoroughly  experienced. 

Cases  frequently  arise  in  which  it  is  impossible  to  bring  the  chem- 
ist upon  the  ground  in  time  for  the  autopsy.  In  such  cases  the  phy- 
sician should  remember  that  that  portion  of  the  poison  remaining  in 
the  alimentary  tract  (we  are  speaking  of  true  poisons)  is  but  the 
residue  of  the  dose  in  excess  of  that  which  has  been  necessary  to  pro- 
duce death;  and,  if  the  processes  of  elimination  have  been  active, 
there  may  remain  no  trace  of  the  poison  in  the  alimentary  canal, 
while  it  still  may  be  detectable  in  the  deeper -seated  organs.  The 
poison  may  also  have  been  administered  by  another  channel  than  the 
mouth,  in  which  event  it  may  not  reach  the  stomach. 

For  these  reasons  it  is  not  sufficient  to  send  the  stomach  alone  for 
analysis.  The  chemist  should  also  receive  the  entire  intestinal  canal, 
the  liver,  the  spleen,  one  or  both  kidneys,  a  piece  of  muscular 
tissue  from  the  leg,  the  brain,  and  any  urine  that  may  remain 


ARSENIC  131 

in  the  bladder.  The  intestinal  canal  should  be  removed  and 
sent  to  the  chemist  without  having  been  opened,  and  with  ligatures, 
enclosing  the  contents,  at  the  two  ends  of  the  stomach  and  at  the 
lower  end  of  the  intestine.  The  brain  and  alimentary  canal  are  to  be 
placed  in  separate  jars,  and  the  other  viscera  in  another  jar  together; 
the  urine  in  a  vial  by  itself.  All  of  these  vessels  are  to  be  new  and 
clean,  and  are  to  be  closed  by  new  corks,  or  by  glass  stoppers,  or 
covers  (not  zinc  screw -caps),  which  are  then  coated  with  paraffin  (not 
sealing-wax),  and  so  fastened  with  strings  and  seals,  that  it  is  impos- 
sible to  open  the  vessels  without  cutting  the  strings  or  breaking*  the 
seals.  Any  vomited  matters  are  to  be  preserved.  If  the  physician 
fail  to  observe  these  precautions,  he  has  probably  made  the  breach  in 
the  evidence  through  which  the  criminal  will  escape,  and  has  at  the 
outset  defeated  the  aim  of  the  analysis. 

Analytical  Characters  of  the  Arsenical  Compounds. — Arsenous 
Compounds. —  (l)  H^S,  a  yellow  color  in  neutral  or  alkaline  liquids; 
a  yellow  ppt.  in  acid  liquids.  The  ppt.  dissolves  in  solutions  of  the 
alkaline  hydroxids,  carbonates  and  sulf hydrates ;  but  is  scarcely 
affected  by  HC1.  Hot  HNO3  decomposes  it. 

(2)  AgNOs,  in  the  presence  of  a  little  NH4HO,  gives  a  yellow 
ppt.     This  test  is  best  applied  by  placing  the  neutral  arsenical  solu- 
tion in  a  porcelain  capsule,  adding  neutral  solution  of  AgNOs,  and 
blowing   upon  it   over  the 

stopper  of  the  NH4HO  bottle, 
moistened  with  that  reagent. 

(3)  CuSC>4  under  the  same 
conditions   as  in   (2)  gives  a 
yellowish  green  ppt. 

(4)  A    small  quantity   of 
solid  As2Os  is  placed  in  the 
point  a  of  the  tube,  Fig.  28; 
above  it,  at  ft,  a  splinter  of 

recently  ignited  charcoal;  6  is  Fio 

first  heated  to  redness,  then 

a;  the  vapor  of  As2Os,  passing  over  the  hot  charcoal,  is  reduced,  and 
elementary  As  is  deposited  at  c  in  a  metallic  ring.  The  tube  is  then 
cut  between  a  and  c,  the  larger  piece  held  with  d  uppermost  and 
heated  at  c;  the  deposit  is  volatilized,  the  odor  of  garlic  is  observed, 
and  bright,  octahedral  crystals  (Fig.  30)  appear  in  the  cool  part  of 
the  tube. 

(5)  Reinsch  Test.— The  suspected  liquid  is  acidulated  with  one- 
sixth  its  bulk  of  HCL     Strips  of  electrotype  copper  are  immersed  in 
the  liquid,   which  is  boiled.     In  the  presence  of  an  arsenous  com- 
pound, a  gray  or  bluish  deposit  is  formed  upon  the  Cu,     A  similar 


i;;j  MANUAL    OF    CHEMISTRY 

deposit  is  produced  by  other  substances  (S,  Au,  Pt,  Bi,  Sb,  Hg)  .  To 
complete  the  test  the  Cu  is  removed,  washed,  and  dried  between  folds 
of  filter  paper,  without  removing  the  deposit.  The  copper,  with  its  ad- 
herent film,  is  rolled  into  a  cylinder,  and  introduced  into  a  dry  piece 
of  Bohemian  tubing,  about  one-fourth  inch  in  diameter  and  six  inches 
long,  which  is  held  at  the  angle  shown  in  Fig.  29  and  heated  at  the 
point  containing  the  copper.  If  the  deposit  consist  of  arsenic,  a 
white  deposit  is  formed  at  a,  which  contains  brilliant  specks,  and, 
when  examined  with  a  magnifier,  is  found  to  consist  entirely  of 
minute  octahedral  crystals  (Fig.  30). 

If  the  stain  upon  the  copper,  formed  in  the  first  part  of  the  reac- 
tion, have  been  caused  by  S,  Au,  Pt,  or  Bi,  no  sublimate  is  produced 
during  the  subsequent  heating  in  the  glass  tube,  as  the  product  of 
oxidation  of  sulfur  is  gaseous,  Au  and  Pt  are  neither  oxidized  nor 
volatilized,  and  Bi  is  oxidized,  but  its  oxid  is  not  volatile.  Subli- 
mates are,  however,  formed  from  deposits  caused  by  Sb  or  Hg,  which 


FIG.  29.  FIG.  30. 

differ  from  that  produced  by  arsenic  in  the  following  respects:  That 
from  Sb  consists  of  Sb2Os,  which,  although  isodimorphous  with  AS2O3, 
does  not  crystallize  under  these  conditions,  except,  sometimes,  to 
form  prismatic  crystals  at  the  heated  part  of  the  tube,  or  an  occa- 
sional octahedral  crystal  beyond.  The  sublimate  is  entirely,  or 
almost  entirely  amorphous,  or  granular,  possibly  containing  one  or 
two  octahedral  crystals,  whose  borders  are  darker  than  those  of 
As2Oa.  The  sublimate  from  Hg  consists  of  microscopic  globules  of 
the  liquid  metal.  Reinsch's  reaction  is,  therefore,  a  test  for  anti- 
mony and  mercury,  as  well  as  for  arsenic. 

The  advantages  of  this  test  are:  it  may  be  applied  in  the  presence 
of  organic  matter,  to  the  urine  for  instance  ;  it  is  easily  conducted  ; 
and  its  positive  results  are  not  misleading,  if  the  test  be  carried  to 
completion.  These  advantages  render  it  the  most  suitable  method  for 
the  physician  to  use,  during  the  life  of  the  patient.  It  should  not  be 
used  after  death  by  the  physician,  as  by  it  copper  is  introduced  into 
the  substances  under  examination,  which  may  subsequently  interfere 
seriously  with  the  analysis.  The  purity  of  the  Cu  and  HC1  must  be 


ARSENIC 


133 


proved  by  a  blank  testing  before  use.  Reinsch's  test  is  not  as  deli- 
cate as  Marsh's,  and  it  only  reacts  slowly  and  imperfectly  when  the 
arsenic  is  in  the  higher  stage  of  oxidation,  or  in  presence  of  oxidizing 
agents. 

(6)  Marsh's  test  is  based  upon  the  formation  of  AsH3  when  a 
reducible  compound  of  arsenic  is  in  presence  of  nascent  H;  and  the 
subsequent  decomposition  of  the  arsenical  gas  by  heat,  with  separa- 
tion of  elementary  arsenic. 

The  apparatus  used  (Fig.  31)  consists  of  a  glass  generating  vessel, 
a,  of  about  150  cc.  capacity, provided  with  a  funnel-tube  having  a 
stop -cock,  and  a  lateral  outlet,  either  fitted  in  with  a  cork,  or,  better, 
ground  in.  The  lateral  outlet  is  connected  with  a  tube,  6,  filled  with 
fragments  of  calcium  chlorid ;  which  in  turn  connects  with  the 


FIG.  31. 

Bohemian  glass  tube,  cc,  which  should  be  about  0.5  cent,  in  diam- 
eter, and  about  80  cent.  long.  The  tube  is  protected  by  a  tube  of 
wire  gauze,  within  which  it  is  adjusted  in  the  furnace  as  shown  in 
the  figure.  The  other  end  of  cc  is  bent  downward,  and  dips  into  a 
solution  of  silver  nitrate  in  the  test-tube,  d. 

The  vessel  a  is  first  charged  with  about  25  grams  of  an  alloy 
of  pure  granulated  zinc,  with  a  small  quantity  of  platinum.  The 
apparatus  is  then  connected  gas-tight,  and  the  funnel  tube  about 
half  filled  with  H2SO4,  diluted  with  an  equal  bulk  of  EbO,  and  cooled. 
By  opening  the  stopcock,  the  acid  is  brought  in  contact  with  the  zinc 
in  small  quantities,  in  such  a  manner  that  during  the  entire  testing 
bubbles  of  gas  pass  through  d  at  the  rate  of  60-80  per  minute. 
After  fifteen  minutes  the  burner  is  lighted,  and  the  heating  continued, 
during  evolution  of  gas  from  zinc  and  E^SCU,  for  an  hour.  At  the 
end  of  that  time,  if  no  stain  have  formed  in  cc  beyond  the  burner,  the 
zinc  and  acid  may  be  considered  to  be  pure,  and  the  suspected  solu- 
tion, which  must  have  been  previously  freed  from  organic  matter  and 
from  tin  and  antimony,  is  introduced  slowly  through  the  funnel -tube. 


134 


MANUAL    OF    CHEMISTRY 


If  arsenic  be  present  in  the  substance  examined,  a  hair -brown  or 
gray  deposit  is  formed  in  the  cool  part  of  cc  beyond  the  heated  part. 
At  the  same  time  the  contents  of  d  are  darkened  if  the  amount  of  As 
present  is  so  great  that  all  the  AsH3  produced  is  not  decomposed  in 
the  heated  portion  of  cc. 

To  distinguish  the  stains  produced  by  arsenical  compounds  from 
the  similar  ones  produced  by  antimony  the  following  differences  are 
noted  : 


The  Arsenical  Stain. 

First.  —  Is  farther  removed  from  the 
heated  portion  of  the  tube,  and,  if 
small  in  quantity,  is  double  —  the  first 
hair-brown,  the  second  steel-gray. 

Second.  —  Volatilizes  readily  when 
heated  in  an  atmosphere  of  hydrogen, 
being  deposited  farther  along  in  the 
tube.  The  escaping  gas  has  the  odor 
of  garlic. 

Third.  —  When  cautiously  heated  in  a 
current  of  oxygen,  brilliant,  white, 
octahedral  crystals  of  arsenic  trioxid 
are  deposited  farther  along  in  the  tube. 

Fourth.  —  Instantly  soluble  in  solu- 
tion of  sodium  hypochlorite. 

Fifth.  —  Slowly  dissolved  by  solution 
of  ammonium  sulfhydrate  ;  more  rap- 
idly when  warmed. 

Sixth.  — The  solution  obtained  in  five 
leaves,  on  evaporation  over  the  water- 
bath,  a  bright  yellow  residue. 

Seventh. — The  residue  obtained  in 
six  is  soluble  in  aqua  ammonise,  but 
insoluble  in  hydrochloric  acid. 

Eighth. — Is  soluble  in  warm  nitric 
acid ;  the  solution  on  evaporation  yields 
a  white  residue,  which  turns  brick -red 
when  moistened  with  silver  nitrate 
solution. 

.\inth.  —  Is  not  dissolved  by  a  solu- 
tion of  stannous  chlorid. 


The  Antimonial  Stain. 

First. — Is  quite  near  the  heated  por- 
tion of  the  tube.  A  second  stain  is  also 
usually  formed  in  front  of  the  heated 
part  of  the  tube. 

Second.  —  Requires  a  much  higher 
temperature  for  its  volatilization ;  fuses 
before  volatilizing.  Escaping  gas  has 
no  alliaceous  odor. 

Third.  —  No  crystals  formed  by  heat- 
in^g  in  oxygen,  but  an  amorphous,  white 
sublimate  (see  p.  132). 

Fourth. — Insoluble  in  solution  of 
sodium  hypochlorite. 

Fifth.  —  Dissolves  quickly  in  solution 
of  ammonium  sulfhydrate. 

Sixth.  —  The  solution  obtained  in  five 
leaves,  on  evaporation  over  the  water- 
bath,  an  orange -red  residue. 

Seventh.  —  The  residue  obtained  in 
six  is  insoluble  in  aqua  ammoniae,  but 
soluble  in  hydrochloric  acid. 

Eighth. — Is  soluble  in  warm  nitric 
acid;  the  solution  on  evaporation  yield.* 
a  white  residue,  which  is  not  colored 
when  moistened  with  silver  nitratu 
solution. 

Ninth. — Dissolves  slowly  in  solution 
of  stannous  chlorid. 


The  silver  solution  in  d  is  tested  for  arsenous  acid,  by  floating 
upon  its  surface  a  layer  of  diluted  NH4HO  solution,  which,  in  the 
presence  of  arsenic,  produces  a  yellow  (not  brown)  band,  at  the  point 
of  junction  of  the  two  liquids. 

In  place  of  bending  the  tube  c  downward,  it  may  be  bent  upward 
:uid  drawn  out  to  a  fine  opening.  If  the  escaping  gas  be  then  ignited, 
tin-  heating  of  the  tube  being  discontinued,  a  white  deposit  of  As2O3 


AESENIC  135 

may  be  collected  on  a  glass  surface  held  above  the  flame  ;  or  a  brown 
deposit  of  elementary  As  upon  a  cold  (porcelain)  surface  held  in  the 
flame. 

In  place  of  generating  nascent  hydrogen  by  the  action  of  Zn  on 
H<2SO4,  it  may  be  produced  by  the  decomposition  of  acidulated  H2O 
by  the  battery,  in  a  Marsh  apparatus  especially  modified  for  that 
purpose. 

In  another  modification  of  the  Marsh  test  the  AsHa  is  decomposed, 
not  by  passage  through  a  red-hot  tube,  but  by  passing  through  a 
tube  traversed  by  the  spark  from  an  induction  coil. 

(7)  Fresenius'  and  Von   Babo's  test.  —  The  sulfid,  obtained  in 
(1),  is  dried,  and  mixed  with  12  parts  of  a  dry  mixture  of  3  pts. 
sodium   carbonate    and   1    pt.    potassium   cyanid,    and   the   mixture 
brought  into  a  tube,  drawn  out  to  a  fine  opening,  through  which  a 
slow  current  of  €62  is  allowed  to  pass.     The  tube  is  then  heated  to 
redness  at  the  point  containing  the  mixture,  when,   if   arsenic  be 
present,  a  gray  deposit  is  formed  at  the  constricted  portion  of  the 
tube  ;   which  has  the  characters  of  the  arsenical  stain  indicated  on 
p.  134. 

(8)  Place  a  small  crystal  of  sodium  sulfite  in  a  solution  of  0.3-0.4 
gram  of  stannous  chlorid  in  pure  HC1,  sp.  gr.  1.13.     Float  the  liquid 
to  be  tested  on  the  surface  Of  this  mixture.     If  As  be  present  a  yellow 
band  is  formed  at  the  junction  of  the  two  liquids,  and  gradually 
increases  upwards. 

ARSENIC  COMPOUNDS. — (1)  H2S  does  not  form  a  ppt.  in  neutral 
or  alkaline  solutions.  In  acid  solutions  a  yellow  ppt.,  consisting 
either  of  As2Ss  or  As2S5,  or  a  mixture  of  the  sulfids  with  free  S,  is 
formed  only  after  prolonged  passage  of  H^S  at  the  ordinary  tempera- 
ture, more  rapidly  at  about  70°  (158°  F.). 

(2)  AgNOs,  under  the  same  conditions  as  with  the  arsenous  com- 
pounds, produces  a  brick-red  ppt.  of  silver  arsenate. 

(3)  CuSCU  under  like  circumstances  produces  a  bluish  green  ppt. 
Arsenic  compounds  behave  like  arsenous  compounds  with  the  tests 

4,  6  and  7  for  the  latter. 

Method  of  Analysis  for  Mineral  Poisons. — In  cases  of  suspected 
poisoning  a  systematic  course  of  analysis  is  to  be  followed  by  which  the 
presence  or  absence  of  all  the  more  usual  poisons  can  be  determined. 
The  most  advantageous  process  for  this  purpose  is  that  of  Fresenius 
and  Van  Babo,  somewhat  modified,  in  which  the  animal  and  vegetable 
substances  are  disintegrated  and  oxidized  by  a  mixture  of  HC1  and 
KClOa,  and  in  which  arsenic  and  antimony,  if  present,  are  separated 
before  application  of  the  Marsh  test.  For  descriptions  of  the 
methods,  which  are  somewhat  intricate,  the  student  is  referred  to 
more  comprehensive  works. 


136  MANUAL    OF    CHEMISTRY 

ANTIMONY. 

Symbol=Sb  (Latin:  stibium)—  Atomic  weight=12Q  (O=16  :  120; 
11=1  :  119.04)—  Molecular  weight=(D—8p.  gr.  =6.  II  5—  Fuses  at  450° 
_>0  P.). 
Occurrence.—  Free  in  small  quantity;   principally  in  the  trisulfid, 


Preparation.  —  The  native  sulfid  (black  or  crude  antimony)  is 
roasted,  and  then  reduced  by  heating  with  charcoal. 

Properties.—  Physical.—  A  bluish  gray,  brittle  solid,  having  a 
metallic  luster;  readily  crystallizable;  tasteless  and  odorless;  vola- 
tilizes at  a  red  heat,  and  may  be  distilled  in  an  atmosphere  of  H. 

Chemical.—  Is  not  altered  by  dry  or  moist  air  at  ordinary  tempera- 
tures. When  sufficiently  heated  in  air,  it  burns,  with  formation  of 
SboOa,  as  a  white,  crystalline  solid.  It  also  combines  directly  with 
Cl,  Br,  I,  S,  and  many  metallic  elements.  It  combines  with  H  under 
the  same  circumstances  as  does  As.  Cold  dilute  H2SO4  does  not  affect 
it  ;  the  hot  concentrated  acid  forms  with  it  antimonyl  sulfate 
(SbO)2SO4  and  SO2.  Hot  HC1  dissolves  it,  when  finely  divided,  with 
evolution  of  H.  It  is  readily  oxidized  by  HN03,  with  formation  of 
H3Sb04  or  80204.  Aqua  regia  dissolves  it  as  SbCl3,  or  SbCl5.  Solu- 
tions of  the  alkaline  hydroxids  do  not  act  on  it. 

The  element  does  not  form  salts  with  the  oxyacids.  There  are, 
however,  compounds,  formed  by  the  substitution  of  the  group  antimo- 
nyl (SbO)  ,  for  the  basic  hydrogen  of  those  acids.  (See  Tartar  emetic)  . 

It  enters  into  the  composition  of  type  metal,  anti-friction  metals, 
and  britannia  metal. 

Hydrogen  Antimonid  —  Stibin  —  Antimoniuretted  hydrogen  —  Stib- 
amin  —  Stibonia  —  SbHs  —  123.—  It  is  produced,  mixed  with  H,  when  a 
reducible  compound  of  Sb  is  in  presence  of  nascent  H.  It  is  obtained 
in  larger  amount  by  decomposing  an  alloy  of  400  parts  of  a  2% 
sodium  amalgam,  and  8  parts  of  freshly  reduced,  and  dried  Sb,  by 
EbO,  in  a  current  of  C(>2. 

It  is  a  colorless,  odorless,  combustible  gas,  subject  to  the  same 
decompositions  as  AsH3;  from  which  it  differs  in  being  by  no  means 
as  poisonous,  and  in  its  action  upon  silver  nitrate  solution.  The 
arsenical  gas  acts  upon  the  silver  salt  according  to  the  equation: 
6AgN03+2AsH3+H2=Ag2-h2Ag2HAsO3+6HNO2,  and  the  precipitate 
formed  is  elementary  silver,  while  Ag2HAsO3  remains  in  the  solution. 
In  the  case  of  SbH3  the  reaction  is  3AgNO3-f  SbH3=3HN03+SbAg3, 
all  of  the  Sb  being  precipitated  in  the  black  silver  antimonid. 

Chlorids  of  Antimony.  —  Antimony  Trichlorid  —  Protochlorid  or 
luttrr  of  antimony—  SbGla—  226.5  —  is  obtained  by  passing  dry  Cl  over 
an  excess  of  Sb2S3;  by  dissolving  Sb2S3  in  HC1;  or  by  distilling  mix- 


ANTIMONY  137 

tares,  either  of  Sb2Ss  and  mercuric  chlorid,  or  of  Sb  and  mercuric 
chlorid,  or  of  antimonyl  pyrosulfate  and  sodium  chlorid. 

At  low  temperatures  it  is  a  solid,  crystalline  body;  at  the  ordinary 
temperature  a  yellow,  semi -solid  mass,  resembling  butter;  at  73.2° 
(164°  F.)  it  fuses  to  a  yellow,  oily  liquid,  which  boils  at  223° 
(433.4°  F.).  Obtained  by  a  solution  of  Sb2S3  in  HC1  of  the  usual 
strength,  it  forms  a  dark  yellow  solution,  which,  when  concentrated 
to  sp.  gr.  1.47,  constitutes  the  Liq.  Antimonii  Moridi  (Br.). 

It  absorbs  moisture  from  air,  and  is  soluble  in-  a  small  quantity  of 
H20;  with  a  larger  quantity  it  is  decomposed,  with  precipitation  of  a 
white  powder,  powder  of  Algaroth,  whose  composition  is  SbOCl  if 
cold  H2O  be  used,  and  Sb405Cl2  if  the  H2O  be  boiling.  In  H2O 
containing  15  per  cent,  or  more  HC1,  SbCla  is  soluble  without  decom- 
position. 

Antimony  Pentachlorid — SbCls—  297.5 —  is  formed  by  the  action 
of  Cl,  in  excess,  upon  Sb  or  SbCls. 

It  is  a  fuming,  colorless  liquid.  With  a  small  quantity  of  H2O, 
and  by  evaporation  over  H2SO4,  it  forms  a  hydrate,  SbCls4H2O,  which 
appears  in  transparent,  deliquescent  crystals.  With  more  H2O,  a 
crystalline  oxychlorid,  SbOCls,  is  formed;  and  with  a  still  greater 
quantity,  a  white  precipitate  of  orthoantimonic  acid,  HsSbC^. 

Compounds  of  Antimony  and  Oxygen. — Three  are  known,  Sb2Os, 
Sb2O4  and  Sb205. 

Antimony  Trioxid — Antimonous  anhydrid — Oxid  of  antimony — 
Antimonii  oxidum  (U.  S.;  Br.) — Sb2Os — 288 — occurs  in  nature; 
and  is  prepared  artificially  by  decomposing  the  oxychlorid;  or  by 
heating  Sb  in  air. 

It  crystallizes  in  prisms  or  in  octahedra,  and  is  isodimorphous 
with  As2Oa,  or  is  an  amorphous,  insoluble,  tasteless,  odorless  powder; 
white  at  ordinary  temperatures,  but  yellow  when  heated.  It  fuses 
readily,  and  may  be  distilled  in  absence  of  oxygen.  Heated  in  air,  it 
burns  like  tinder,  and  is  converted  into  Sb204. 

It  is  reduced,  with  separation  of  Sb,  when  heated  with  charcoal, 
or  in  H.  It  is  also  readily  oxidized  by  HNOs,  or  potassium  perman- 
ganate. It  dissolves  in  HC1  as  SbCls;  in  Nordhausen  sulfuric  acid, 
from  which  solution  brilliant  crystalline  plates  of  antimonyl  pyrosul- 
fate, (SbO)2S2O?,  separate;  and  in  solutions  of  tartaric  acid,  and  of 
hydropotassic  tartrate  (see  Tartar  emetic).  Boiling  solutions  of  alka- 
line hydroxids  convert  it  into  antimonic  acid. 

Antimony  Pentoxid — Antimonic  anhydrid — Sb2Os — 320 — is  ob- 
tained by  heating  metantimonic  acid  to  dull  redness.  It  is  an  amor- 
phous, tasteless,  odorless,  pale  lemon -yellow  colored  solid;  very  spar- 
ingly soluble  in  water  and  in  acids.  At  a  red  heat  it  is  decomposed 
into  Sb2O4  and  O. 


138  MANUAL    OF    CHEMISTRY 

Antimony  Antimonate— Intermediate  oxid—Diantimonic  tetroxid 
— Sb2O4— 304 — occurs  iii  nature  and  is  formed  when  the  oxids  or 
hydrates  of  Sb  are  strongly  heated,  or  when  the  lower  stages  of  oxi- 
dation or  the  sulfids  are  oxidized  by  HNO3,  or  by  fusion  with  sodium 
nitrate.  It  is  soluble  in  H2O ;  but  is  decomposed  by  HC1,  hydro- 
potassic  tartrate,  and  potash. 

Antimony  Acids. — The  normal  antimonous  acid,  H3SbO3,  corre- 
sponding to  H3PO3,  is  unknown;  but  the  series  of  antimonic  acids: 
ortho,  H3SbO4;  pyro,  H4Sb2O7;  and  meta,  HSbO3,  is  complete,  either 
in  the  form  of  salts,  or  in  that  of  the  free  acids.  There  also  exists, 
in  its  sodium  salt,  a  derivative  of  the  lacking  antimonous  acid:  met- 
antimonous  acid,  HSbO2. 

The  compound  sometimes  used  in  medicine  under,  the  name  washed 
diaphoretic  antimony  is  potassium  metantimonate,  united  with  an 
excess  of  the  pentoxid:  2KSb03,  Sb2Os.  The  hydropotassic  pyroan- 
timonate,  K2H2Sb2C>76Aq  is  a  valuable  reagent  for  the  sodium  com- 
pounds. It  is  obtained  by  calcining  a  mixture  of  one  part  of  antimony 
with  four  parts  potassium  nitrate,  and  fusing  the  product  with  its 
own  weight  of  potassium  carbonate. 

Sulfids  of  Antimony. — Antimony  Trisuliid—Sesquisulfid  of  anti- 
mony— Black  antimony — Antimonii  sulfidum  (U.  S.) — Antimonium 
nigrum  (Br.) — Sb2S3 — 336 — is  the  chief  ore  of  antimony;  and  is 
formed  when  H2S  is  passed  through  a  solution  of  tartar  emetic. 

The  native  sulfid  is  a  steel-gray,  crystalline  solid;  the  artificial 
product,  an  orange -red,  or  brownish  red,  amorphous  powder.  The 
crude  antimony  of  commerce  is  in  conical  loaves,  prepared  by  simple 
fusion  of  the  native  sulfid.  It  is  soft,  fusible,  readily  pulverized,  and 
has  a  bright  metallic  luster. 

Heated  in  air,  it  is  decomposed  into  S(>2  and  a  brown,  vitreous, 
more  or  less  transparent  mass,  composed  of  varying  proportions  of 
oxid  and  oxysulfids,  known  as  crocus,  or  liver,  or  glass  of  antimony. 
Sb2S3  is  an  anhyrid,  corresponding  to  which  are  salts  known  as  thio- 
antimonites,  having  the  general  formula  M^HSbSs.  If  an  excess  of 
Sb2S3  be  boiled  with  a  solution  of  potash  or  soda,  a  liquid  is  obtained, 
which  contains  an  alkaline  thioantimonite,  and  an  excess  of  Sb2$3. 
If  this  solution  be  filtered,  and  decomposed  by  an  acid  while  still  hot, 
an  orange -colored,  amorphous  precipitate  is  produced,  which  is  the 
antimonium  sulfuratum  (U.  S.;  Br.),  and  consists  of  a  mixture,  in 
varying  proportions,  of  Sb2S3  and  Sb2O3.  If,  however,  the  solution 
be  allowed  to  cool,  a  brown,  voluminous,  amorphous  precipitate 
separates,  which  consists  of  antimony  trisulfid  and  trioxid,  potassium 
or  sodium  sulfid,  and  alkaline  thioantimonite  in  varying  proportions; 
and  is  known  as  Kermes  mineral.  If  now  the  solution  from  which 
the  Kermes  has  been  separated,  be  decomposed  with  H2SO4  a  reddish 


ANTIMONY  139 

yellow  substance  separates,  which  is  the  golden  sulfuret  of  antimony, 
and  consists  of  a  mixture  of  80283  and  Sb28s.  The  precipitate  obtained 
when  H2S  acts  upon  a  solution  of  an  antimonial  compound  is,  accord- 
ing to  circumstances,  Sb2$3  or  Sb2$5,  mixed  with  free  S.  By  the 
action  of  HC1  on  Sb2Sa,  H.2S  is  produced. 

Antimony  Pentasulfid — Sb2Ss — 400 — is  obtained  by  decomposing 
an  alkaline  thioantimonate  by  an  acid.    It  is  a  dark  orange -red,  amor-  • 
phous  powder,  readily  soluble  in  solutions  of  the  alkalies,  and  alkaline 
sulfids,  with  which  it  forms  thioantimonates. 

An  oxysulfid,  SbeSeOa,  is  obtained  by  the  action  of  a  solution  of 
sodium  thiosulfate  upon  SbCls  or  tartar  emetic.  It  is  a  fine  red  pow- 
der, used  as  a  pigment,  and  called  antimony  cinnabar  or  antimony 
vermilion. 

Action  of  Antimony  Compounds  on  the  Economy.  —  The  com- 
pounds of  antimony  are  poisonous,  and  act  with  greater  or  less 
energy  as  they  are  more  or  less  soluble.  The  compound  which  is 
most  frequently  the  cause  of  antimonial  poisoning  is  tartar  emetic 
(q.  v.),  which  has  caused  death  in  a  quantity  of  three  grains,  in 
divided  doses,  although  recovery  has  followed  the  ingestion  of  half 
an  ounce  in  several  instances.  Indeed,  the  chances  of  recovery 
seem  to  be  better  with  large,  than  with  small  doses,  probably  owing 
to  the  more  rapid  and  complete  removal  of  the  poison  by  vomiting 
with  large  doses.  Antimonials  have  been  sometimes  criminally  ad- 
ministered in  small  and  repeated  doses,  the  victim  dying  of  exhaus- 
tion. In  such  a  case  an  examination  of  the  urine  will  reveal  the 
cause  of  the  trouble. 

If  vomiting  have  not  occurred  in  cases  of  acute  autimonial  poi- 
soning it  should  be  provoked  by  warm  water,  or  the  stomach  should 
be  washed  out.  Tannin  in  some  form  (decoction  of  oak  bark,  cin- 
chona, nutgalls,  tea)  should  then  be  given,  with  a  view  to  rendering 
any  remaining  poison  insoluble. 

Medicinal  antimonials  are  very  liable  to  contamination  with 
arsenic. 

Analytical  Characters  of  Antimonial  Compounds. — (l)  With 
H2S  in  acid  solution:  an  orange -red  ppt.,  soluble  in  NUiHS  and  in 
hot  HC1. 

(2)  A  strip  of  bright  copper,  suspended  in  a  boiling  solution  of 
an  Sb  compound,  acidulated  with  HC1,  is  coated  with  a  blue -gray 
deposit.     This  deposit  when  dried  (on  the  copper),  and  heated  in  a 
tube,  open  at  both  ends  yields  a  white,  amorphous  sublimate  (see  No. 
5,  p.  131). 

(3)  Antimonial  compounds  yield  a  deposit  by  Marsh's  test,  sim- 
ilar to  that  obtained  with  arsenical  compounds,  but  differing  in  the 
particulars  given  above  (see  No.  6,  p.  134). 


140  MANUAL    OF    CHEMISTRY 

IV.     BORON   GROUP. 

BORON. 

Symbol=E— Atomic  iveight=ll  (0=16:11;  H=l:10.91)—Jfote- 
cnhtr  weight=22  (1)=Isolated  by  Davy  in  1807. 

Boron  occurs  in  nature  in  the  borates  of  Ca,  Mg,  and  Na,  princi- 
pally as  sodium  pyroborate  (borax).  It  constitutes  a  group  by  itself; 
it  is  trivalent  in  all  of  its  compounds;  it  forms  but  one  oxid,  which 
is  the  anhydrid  of  a  tribasic  acid;  and  it  forms  no  compound 
with  H. 

It  is  separable  in  two  allotropic  modifications.  Amorphous 
boron  is  prepared  by  decomposition  of  the  oxid,  by  heating  with 
metallic  potassium  or  sodium.  It  is  a  greenish  brown  powder; 
sparingly  soluble  in  H2O;  infusible;  and  capable  of  direct  union  with 
01,  Br,  O,  S,  and  N.  Crystallized  boron  is  produced  when  the  oxid, 
chlorid  or  fluorid  is  reduced  by  Al.  It  crystallizes  in  quadratic 
prisms;  more  or  less  transparent,  and  varying  in  color  from  a  faint 
yellow  to  deep  garnet-red;  very  hard;  sp.  gr.  2.68.  It  burns  when 
strongly  heated  in  O,  and  readily  in  Cl;  it  also  combines  with  N, 
which  it  is  capable  of  removing  from  NH3  at  a  high  temperature. 

Boron  Trioxid. — Boric  or  boracic  anhydrid — B2O3 — 70 — is  obtained 
by  heating  boric  acid  to  redness  in  a  platinum  vessel.  It  is  a  trans- 
parent, glass -like  mass,  used  in  blowpipe  analysis  under  the  name 
vitreous  boric  acid. 

Boric    Acids.  —  Boric  Acid  —  Boracic   acid  —  Orthoboric   acid  - 
Acidum  boricum  (U.  S.) — H3BO3 —  62 — occurs  in  nature;  and  is 
prepared  by  slowly  decomposing  a  boiling,  concentrated  solution  of 
borax,  with  an  excess  of  H2SO4,  and  allowing  the  acid  to  crystallize. 

It  forms  brilliant,  crystalline  plates,  unctuous  to  the  touch;  odor- 
less; slightly  bitter;  soluble  in  34  parts  H2O  at  10°  (50°  F.) ;  soluble 
in  alcohol.  Its  solution  reddens  litmus,  but  turns  turmeric  paper 
brown.  When  its  aqueous  solution  is  distilled,  a  portion  of  the  acid 
passes  over. 

Boric  acid  readily  forms  esters  with  the  alcohols.  When  heated 
with  ethylic  alcohol,  ethyl  borate  is  formed,  which  burns  with  a 
green  flame.  Heated  with  glycerol,  a  soluble,  neutral  ester  is 
formed,  known  as  boroglycerid,  and  used  as  an  antiseptic. 

If  H3BO3  be  heated  for  some  time  at  80°  (176°  F.),  it  loses  H2O 
and  is  converted  into  metaboric  acid,  HBO2.  If  maintained  at  100° 
(212°  F.)  for  several  days,  it  loses  a  further  quantity  of  EbO,  and  is 
converted  into  tetraboric  or  pyroboric  acid,  H^B^,  whose  sodium 
salt  is  borax. 


CARBON  141 


V.  CARBON  GROUP. 

CAEBON —  SILICON. 

i 

The  elements  of  this  group  are  bivalent  or  quadrivalent.  The 
saturated  oxid  of  each  is  the  anhydrid  of  a  dibasic  acid.  They*  are 
both  combustible,  and  each  occurs  in  three  allotropic  forms. 

CARBON. 

8ymbol=C— Atomic  weight=12  (O=16:12;  H=l:11.9)  —  Mole- 
cular weighl=24:  ( ? ) . 

Occurrence. — Free  in  its  three  allotropic  forms  :  The  diamond 
in  octahedral  crystals  ;  in  alluvial  sand,  clay,  sandstone,  and  con- 
glomerate ;  graphite,  in  amorphous  or  imperfectly  crj^stalline  forms; 
amorphous,  in  the  different  varieties  of  anthracite  and  bituminous 
coal,  jet,  etc.  In  combination,  it  is  very  widely  distributed  in  the 
so-called  organic  substances. 

Properties. — Diamond. — The  crystals  of  diamond,  which  is  al- 
most pure  carbon,  are  usually  colorless  or  yellowish,  but  may  be  blue, 
green,  pink,  brown  or  black.  It  is  the  hardest  substance  known, 
and  the  one  which  refracts  light  the  most  strongly.  Its  index  of 
refraction  is  2.47  to  2.75.  It  is  brittle;  a  bad  conductor  of  heat  and 
of  electricity;  sp.  gr.  3.50  to  3.55.  When  very  strongly  heated  in  air 
it  burns,  without  blackening,  to  carbon  dioxid. 

Graphite  is  a  form  of  carbon  almost  as  pure  as  the  diamond, 
capable  of  crystallizing  in  hexagonal  plates;  sp.gr.  2.2;  dark  gray  in 
color;  opaque;  soft  enough  to  be  scratched  by  the  nail;  and  a  good 
conductor  of  electricity.  It  is  also  known  as  black  lead  or  plum- 
bago. It  has  been  obtained  artificially,  by  allowing  molten  cast-iron, 
containing  an  excess  of  carbon,  to  cool  slowly,  and  dissolving  the 
iron  in  HC1.  When  oxidized  with  potassium  chlorate  and  nitric  acid 
it  yields  graphitic  acid,  CuEUOs. 

Amorphous  carbon  is  met  with  in  a  great  variety  of  forms,  nat- 
ural and  artificial,  in  all  of  which  it  is  black  ;  sp.  gr.  1.6-2.0;  more 
or  less  porous;  and  a  conductor  of  electricity. 

Anthracite  coal  is  hard  and  dense  ;  it  does  not  flame  when  burn- 
ing ;  is  difficult  to  kindle,  but  gives  great  heat  with  a  suitable 
draught.  It  contains  80-90  per  cent,  of  carbon.  Bituminous  coal 
differs  from  anthracite  in  that,  when  burning,  it  gives  off  gases, 
which  produce  a  flame.  Some  varieties  are  quite  soft,  while  others, 
such  as  jet,  are  hard  enough  to  assume  a  high  polish.  It  is  usually 
compact  in  texture,  and  very  frequently  contains  impressions  of 


14-J  MANUAL    OF    CHEMISTRY 

leaves,  and  other  parts  of  plants.  It  contains  about  75  per  cent,  of 
carbon. 

Charcoal,  carbo  ligni,  U.  S.,  is  obtained  by  burning  woody  fiber, 
with  an  insufficient  supply  of  air.  It  is  brittle  and  sonorous;  has  the 
form  of  the  wood  from  which  it  was  obtained,  and  retains  all  the 
mineral  matter  present  in  the  woody  tissue.  Its  sp.  gr.  is  about  1.57. 
It  has  the  power  of  condensing  within  its  pores  odorous  substances 
and  large  quantities  of  gases  ;  90  volumes  of  ammonia,  55  of  hy- 
drogen sulfid,  9.25  of  oxygen.  This  property  is  taken  advantage  of 
in  a  variety  of  ways.  Its  power  of  absorbing  odorous  bodies  renders 
it  valuable  as  a  disinfecting  and  filtering  agent,  and  in  the  preven- 
tion of  putrefaction  and  fermentation  of  certain  liquids.  The  efficacy 
of  charcoal  as  a  filtering  material  is  due  also,  in  a  great  measure,  to 
the  oxidizing  action  of  the  oxygen  condensed  in  its  pores;  indeed,  if 
charcoal  be  boiled  with  dilute  HC1,  dried,  and  heated  to  redness,  the 
oxidizing  action  of  the  oxygen,  which  it  thus  condenses,  is  very 
energetic. 

When  small  strips  of  wood  are  heated  to  redness  in  a  current  of 
vapor  of  carbon  disulfid,  or  of  hydrocarbons,  metallic  carbon  is  pro- 
duced. This  is  very  sonorous,  and  is  a  very  good  conductor  of  heat 
and  of  electricity.  The  filaments  in  incandescent  electric  lamps  are 
prepared  from  vegetable  parchment  or  bamboo  fiber  in  a  similar 
manner. 

Lamp-black  is  obtained  by  incomplete  combustion  of  some  res- 
inous or  tarry  substance,  or  natural  gas,  the  smoke  or  soot  from 
which  is  directed  into  suitable  condensing  chambers.  It  is  a  light, 
amorphous  powder,  and  contains  a  notable  quantity  of  oily  and  tarry 
material,  from  which  it  may  be  freed  by  heating  in  a  covered  vessel. 
It  is  used  in  the  manufacture  of  printer's  ink. 

Coke  is  the  substance  remaining  in  gas  retorts,  after  the  distil- 
lation of  bituminous  coal,  in  the  manufacture  of  illuminating  gas. 
It  is  a  hard,  grayish  substance,  usually  very  porous,  dense,  and 
sonorous.  When  iron  retorts  are  used,  a  portion  of  the  gaseous 
products  are  decomposed  by  contact  with  the  hot  iron  surface,  upon 
which  there  is  then  deposited  a  layer  of  very  hard,  compact,  grayish 
carbon,  which  is  a  good  conductor  of  electricity. 

Animal  charcoal  is  obtained  by  calcining  animal  matters  in  closed 
vessels.  If  prepared  from  bones  it  is  known  as  bone-black,  carbo 
animalis,  U.  S.;  if  from  ivory,  ivory  black.  The  latter  is  used  as  a 
pigment,  the  former  as  a  decolorizing  agent.  Bones  yield  about  60 
per  cent,  of  bone-black,  which  contains,  besides  carbon,  nitrogen 
and  the  phosphates  and  other  mineral  substances  of  the  bones.  It 
possesses  in  a  remarkable  degree  the  power  of  absorbing  coloring 
matters.  When  its  decolorizing  power  is  lost  by  saturation  with  pig- 


SILICON  143 

mentary  bodies,  it  may  be  restored,  although  not  completely,  by  cal- 
cination. For  certain  purposes  purified  animal  charcoal,  i.  e.,  freed 
from  mineral  matter,  carbo  animalis  purificatus,  U.  S.,  is  required, 
and  is  obtained  by  extracting  the  commercial  article  with  HC1,  and 
washing  it  thoroughly.  Its  decolorizing  power  is  diminished  by  this 
treatment.  Animal  charcoal  has  the  power  of  removing  from  a  solu- 
tion certain  crystalline  substances,  notably  the  alkaloids,  and  a 
method  has  been  suggested  for  separating  these  bodies  from  organic 
mixtures  by  its  use. 

All  forms  of  carbon  are  insoluble  in  any  known  liquid. 

Chemical. — All  forms  of  C  combine  with  O  at  high  temperatures, 
with  light  and  heat.  The  product  of  the  union  is  carbon  dioxid  if  the 
supply  of  air  or  O  be  sufficient;  but  if  O  be  present  in  limited  quan- 
tity, carbon  monoxid  is  formed.  The  affinity  of  C  for  O  renders  it  a 
valuable  reducing  agent.  Many  metallic  oxids  are  reduced,  when 
heated  with  C,  and  steam  is  decomposed  when  passed  over  red-hot  C: 
H2O+C=CO-|-H2.  At  elevated  temperatures  C  also  combines  directly 
with  S,  to  form  carbon  disulfid.  With  H,  carbon  also  combines 
directly,  under  the  influence  of  the  voltaic  arc. 

For  Compounds  of  Carbon,  see  page  216. 


SILICON. 

8ymbol=Si— Atomic  weigM=28  (0=16:28.4;   H=l:28.17)—  Mo- 
lecular weight=56  (?) — Discovered  by  Davy,  1807 — Name  from  silex= 


Also  known  as  silicium ;  occurs  in  three  allotropic  forms :  Amor- 
phous silicon,  formed  when  silicon  chlorid  is  passed  over  heated  K  or 
Na,  is  a  dark  brown  powder,  heavier  than  water.  When  heated  in 
air,  it  burns  with  a  bright  flame  to  the  dioxid.  It  dissolves  in  potash 
and  in  hydrofluoric  acid,  but  is  not  attacked  by  other  acids.  Graphi- 
toid  silicon  is  obtained  by  fusing  potassium  fluosilicate  with  alumin- 
ium. It  forms  hexagonal  plates,  of  sp.  gr.  2.49,  which  do  not  burn 
when  heated  to  whiteness  in  O,  but  may  be  oxidized  at  that  tem- 
perature, by  a  mixture  of  potassium  chlorate  and  nitrate.  It  dis- 
solves slowly  in  alkaline  solutions,  but  not  in  acids.  Crystallized 
silicon,  corresponding  to  the  diamond,  forms  crystalline  needles, 
which  are  only  attacked  by  a  mixture  of  nitric  and  hydrofluoric 
acids. 

Silicon,  although  closely  related  to  C,  exists  in  nature  in  compara- 
tively few  compounds.  It  has  been  caused  to  form  artificial  combina- 
tions, however,  which  indicate  its  possible  capacity  to  exist  in  sub- 
stances corresponding  to  those  C  compounds  commonly  known  as 


144  MANUAL    OF    CHEMISTRY 

organic,  e.  g.,   silicichloroform    and   silicibromoform,    SiHCl3   and 

SiHBi-3. 

Hydrogen  Silicid— SiH4— 32— is  obtained  as  a  colorless,  insoluble, 
spontaneously  inflammable  gas,  by  passing  the  current  of  a  galvanic 
battery  of  twelve  cells  through  a  solution  of  common  salt,  using  a 
plate  of  aluminium,  alloyed  with  silicon,  as  the  positive  electrode. 

Silicon  Chlorid— SiCl4— 170— a  colorless,  volatile  liquid,  having 
an  irritating  odor;  sp.  gr.  1.52;  boils  at  59°  (138.2°  F.);  formed 
when  Si  is  heated  to  redness  in  Cl. 

Silicic Oxid— Silicic  anhydrid — Silex— SiO2— 60— is  the  most  im- 
portant of  the  compounds  of  silicon.  It  exists  in  nature  in  the  differ- 
ent varieties  of  quartz,  and  in  the  rocks  and  sands  containing  that 
mineral,  in  agate,  carnelian,  flint,  etc.  Its  purest  native  form  is  rock 
crystal.  Its  hydrates  occur  in  the  opal,  and  in  solution  in  natural 
waters.  When  crystallized,  it  is  fusible  with  difficulty.  When  heated 
to  redness  with  the  alkaline  carbonates,  it  forms  silicates,  which 
solidify  to  glass -like  masses,  on  cooling.  It  unites  with  EbO  to  form 
a  number  of  acid  hydrates.  The  normal  hydrate,  ELtSiC^,  has  not 
been  isolated,  although  it  probably  exists  in  the  solution  obtained  by 
adding  an  excess  of  HC1  to  a  solution  of  sodium  silicate.  A  gelati- 
nous hydrate,  soluble  in  water  and  in  acids  and  alkalies,  is  obtained 
by  adding  a  small  quantity  of  HC1  to  a  concentrated  solution  of 
sodium  silicate. 

Hydrofluosilicic  Acid — H2SiF6— 144— is  obtained  in  solution  by 
passing  the  gas  disengaged  by  gently  heating  a  mixture  of  equal  parts 
of  fluorspar  and  pounded  glass  and  6  pts.  EfeSC^  through  water;  the 
disengagement  tube  being  protected  from  moisture  by  a  layer  of  mer- 
cury. It  is  used  in  analysis  as  a  test  for  K  and  Na. 

Silicon  Carbide — SiC — is  produced  by  the  action  of  a  powerful 
electric  current  upon  a  mixture  of  coke  and  aluminium  silicate.  It 
forms  blue  crystals,  is  very  hard,  and  is  used  as  a  polishing  agent 
under  the  name  Carborundum. 


VI.     VANADIUM  GROUP. 

VANADIUM — NIOBIUM — TANTALUM . 

The  elements  of  this  group  resemble  those  of  the  N  group,  but 
are  usually  quadrivalent. 

Vanadium — V — 51.2— a  brilliant,  crystalline  metal;  sp.  gr.=5.5; 
which  forms  a  series  of  oxids  similar  to  those  of  N.  No  salts  of  V 
are  known,  but  salts  of  vanadyl  (VO)  are  numerous,  and  are  used  in 
the  manufacture  of  anilin  black. 


MOLYBDENUM    GROUP  145 

Niobium  (Columbium) — Nb — 94 — a  bright,  steel-gray  metal;  sp. 
gr.  7.06;  which  burns  in  air  to  Nb2Os  and  in  Cl  to  Nb015;  not  attacked 
by  acids. 

Tantalum — Ta— 183 — closely  resembles  Nb  in  its  chemical  char- 
acters. 

VII.     MOLYBDENUM   GROUP. 

MOLYBDENUM — TUNGSTEN — OSMIUM . 

The  position  of  this  group  is  doubtful;  and  it  is  probable  that  the 
lower  oxids  will  be  found  to  be  basic  in  character,  in  which  case  the 
group  should  be  transferred  to  the  third  class. 

Molybdenum — Mo — 96 — a  brittle  white  metal.  The  oxid  MoOs, 
molybdic  anhydrid,  combines  with  H2O  to  form  a  number  of  acids; 
the  ammonium  salt  of  one  of  which  is  used  as  a  reagent  for  HaPO^ 
with  which  it  forms  a  conjugate  acid,  phosphomolybdic  acid,  used  as  a 
reagent  for  the  alkaloids. 

Tungsten — Wolfram— W— 184 — a  hard,  brittle  metal;  sp.  gr. 
17.4.  The  oxid,  WOs,  tungstic  anhydrid,  is  a  yellow  powder,  forming 
with  EbO  several  acid  hydrates;  one  of  which,  metatungstic  acid,  is 
used  as  a  test  for  the  alkaloids,  as  are  also  the  conjugate  silicotung- 
stic  and  phosphotungstic  acids.  Tissues  impregnated  with  sodium 
tungstate  are  rendered  uninflammable. 

Osmium — Os — 191 — occurs  in  combination  with  Ir  in  Pt  ores; 
combustible  and  readily  oxidized  to  OsO4.  This  oxid,  known  as  osmic 
acid,  forms  colorless  crystals,  soluble  in  EbO,  which  give  off  intensely 
irritating  vapors.  It  is  used  as  a  staining  agent  by  histologists,  and 
also  in  dental  practice. 


10 


146  MANUAL,    OF    CHEMISTRY 


CLASS   III.— AMPHOTERIC    ELEMENTS. 

Elements  whose  Oxids  unite  with  Water,  some  to  form  Bases,  others  to  form 
Acids;  which  form  Oxysalts. 


I.     GOLD  GROUP. 

GOLD. 

Symbol  =  Au  ( Aurum)  —Atomic  weight  =  197  (O  =  16: 197.2; 
H=l :  195.63)—  Molecular  weight=394:  (1)—8p.  0r. =19. 258-19. 367 
-Fuses  at  1200°  (2192°  F.). 

This,  the  only  member  of  the  group,  forms  two  series  of  com- 
pounds; in  one,  AuCl,  it  is  univalent;  in  the  other,  AuCls,  trivalent. 
Its  hydroxid,  auric  acid,  Au(OH)3,  corresponds  to  the  oxid,  Au2O3. 
Its  oxysalts  are  unstable. 

It  is  yellow  or  red  by  reflected  light,  green  by  transmitted  light, 
reddish -pur  pie  when  finely  divided;  not  very  tenacious;  softer  than 
silver;  very  malleable  and  ductile.  It  is  not  acted  on  by  EUO  or  air, 
at  any  temperature,  nor  by  any  single  acid.  It  combines  directly 
with  Cl,  Br,  I,  P,  Sb,  As  and  Hg.  It  dissolves  in  nitromuriatic  acid 
as  auric  chlorid.  It  is  oxidized  by  alkalies  in  fusion  011  contact  with 
air.  Gold  coin  and  jewelry  always  contain  silver  or  copper,  or  both. 
The  proportion  of  gold  present  is  expressed  in  lOOOths  in  coin,  and 
in  "carats"  in  jewelry;  pure  gold  being  24  carats  fine. 

Aurous  Chlorid — AuCl — is  produced  when  auric  chlorid  is  heated 
to  185°  (365°  F.). 

Auric  Chlorid — Gold  trichlorid — AuCls — 303.6 — obtained  by  dis- 
solving Au  in  aqua  regia,  evaporating  at  100°  (212°  F.),  and  purify- 
ing by  crystallization  from  IbO.  Deliquescent,  yellow  prisms,  very 
soluble  in  H^O,  alcohol  and  ether;  readily  decomposed,  with  separa- 
tion of  Au,  by  contact  with  P,  or  with  reducing  agents.  Its  solution, 
treated  with  the  chlorids  ef  tin,  deposits  a  purple  double  stannate  of 
Sn  and  Au,  called  "purple  of  Cassius."  With  alkaline  chlorids  it 
forms  double  chlorids,  chloraurates  (auri  et  sodii  chloridum,  U.  S.). 

Aurous  Oxid — Au2Oa — is  a  violet  powder,  formed  by  the  action  of 
KHO  on  AuCl.  AuricOxid,  Au2Os,  is  brown,  and  very*unstable. 

Analytical  Characters. —  (1)  With  £[28,  from  neutral  or  acid  solu- 
tion: a  blackish-brown  ppt.  in  the  cold;  insoluble  in  HNOs  and  HC1; 
soluble  in  aqua  regia,  and  in  yellow  NELtHS.  (2)  With  stannous 
chlorid  and  a  little  chlorin  water,  a  purple-red  ppt.,  insoluble  in  HC1. 
(3)  With  ferrous  sulf ate:  a  brown  deposit,  which  assumes  the  luster 
of  gold  when  dried  and  burnished. 


CHROMIUM  147 


II.     IRON   GROUP. 

CHROMIUM— MANGANESE— IRON. 

The  elements  of  the  group  form  two  series  of  compounds.  In  one 
they  are  bivalent,  as  in  Fe/xCl2  or  Mn"SO4,  while  in  the  other  they 
are  quadrivalent;  but  when  quadrivalent,  the  atoms  do  not  enter  into 
combination  singly,  but  grouped,  two  together,  to  form  a  hexavalent 

D~e=-i  vi 
,  as  in  (Fe2)viCl6,  (Cr2)viO3.    They  form  several  oxids;  of 

which  the  oxid  MOs  is  an  anhydrid,  corresponding  to  which  are  acids 
and  salts.     Most  of  the  other  oxids  are  basic. 


CHROMIUM. 

Symbol  =Cr  —  Atomic  weight  =  52  (0=16:52.1;  H=l:51.69)  — 
Molecular  weight=104:.12  (?)  —  Sp.  gr.=6.S  —  Discovered  byVauquelin, 
1797  —  Name  from  XP^IM  =  color. 


Occurs  in  nature  principally  as  chrome  ironstone,  a  double  oxid  of 
Cr  and  Fe.  The  element  is  separated  with  difficulty  by  reduction  of 
its  oxid  by  charcoal,  or  of  its  chlorid  by  sodium.  It  is  a  hard,  crys- 
talline, almost  infusible  metal.  Combines  with  O  only  at  a  red  heat. 
It  is  not  attacked  by  acids,  except  HC1;  is  readily  attacked  by  alka- 
lies. 

Chromic  Oxid  —  Sesquioxid,  or  green  oxid  of  chromium  —  feOs  — 
152.2  —  obtained,  amorphous,  by  calcining  a  mixture  of  potassium 
dichromate  and  starch,  or,  crystallized,  by  heating  neutral  potassium 
chromate  to  redness  in  Cl. 

It  is  green;  insoluble  in  H2O,  acids  and  alkalies;  fusible  with 
difficulty,  and  not  decomposed  by  heat;  not  reduced  by  H.  At  a  red 
heat  in  air,  it  combines  with  alkaline  hydroxids  and  nitrates,  to  form 
chromates.  It  forms  two  series  of  salts,  the  terms  of  one  of  which 
are  green,  those  of  the  other  violet.  The  alkaline  hydroxids  separate 
a  bluish-  green  hydrate  from  solutions  of  the  green  salts,  and  a  bluish 
violet  hydrate  from  those  of  the  violet  salts. 

Chromium  green,  or  emerald  green,  is  a  green  hydrate,  formed 
by  decomposing  a  double  borate  of  chromium  and  potassium  by  IbO. 
It  is  used  in  the  arts  as  a  substitute  for  the  arsenical  greens,  and  is 
non-  poisonous. 

Chromic  Anhydrid  —  Acidum  chromicum  (U.  S.)  —  CrOa  —  100  — 
is  formed  by  decomposing  a  solution  of  potassium  dichromate  by 
excess  of  H2SO4,  and  crystallizing. 


148  MANUAL    OF    CHEMISTRY 

It  crystallizes  in  deliquescent,  crimson  prisms,  very  soluble  in  H2O 
and  in  dilute  alcohol.  It  is  a  powerful  oxidant,  capable  of  igniting 
strong  alcohol. 

The  true  chromic  acid  has  not  been  isolated,  but  salts  are  known 
which  correspond  to  three  acid  hydrates:  IbCrO*  =  chromic  acid; 
H2Cr2O7=dichromic  acid ;  and  EbCrsOio^trichromic  acid. 

Chlorids. — Two  chlorids  and  one  oxychlorid  of  chromium  are 
known.  Chromous  chlorid,  CrCh,  is  a  white  solid,  soluble,  with  a 
blue  color,  in  H2O.  Chromic  chlorid,  (Cr2)Cl6,  forms  large  red 
crystals,  insoluble  in  IkO  when  pure. 

Sulfates. — A  violet  sulfate  crystallizes  in  octahedra,  (0)2(804)3+ 
15  Aq,  and  is  very  soluble  in  H2O.  At  100°  it  is  converted  into  a 
green  salt,  (0)2(804)3-1-5  Aq,  soluble  in  alcohol;  which,  at  higher 
temperatures,  is  converted  into  the  red,  insoluble,  anhydrous  salt. 
Chromic  sulfate  forms  double  sulfates,  containing  24  Aq,  with  the 
alkaline  sulfates.  (See  Alums.) 

Analytical  Characters. — CHROMOUS  SALTS. — (1)  Potash:  a  brown 
ppt.  (2)  Ammonium  hydroxid:  greenish  white  ppt.  (3)  Alkaline 
sulfids:  black  ppt.  (4)  Sodium  phosphate:  blue  ppt. 

CHROMIC  SALTS. — (1)  Potash:  green  ppt.;  an  excess  of  precipitant 
forms  a  green  solution,  from  which  C^Os  separates  on  boiling.  (2) 
Ammonium  hydroxid:  greenish -gray  ppt.  (3)  Ammonium  sulf  hy- 
drate: greenish  ppt. 

CHROMATES. — (1)  EbS  in  acid  solution:  brownish  color,  changing 
to  green.  (2)  Ammonium  sulf  hydrate:  greenish  ppt.  (3)  Barium 
chlorid:  yellowish  ppt.  (4)  Silver  nitrate:  brownish  red  ppt.,  soluble 
in  HNOs  or  NELtHO.  (5)  Lead  acetate:  yellow  ppt.,  soluble  in  potash, 
insoluble  in  acetic  acid. 

Action  on  the  Economy. —  Chromic  anhydrid  oxidizes  organic 
substances,  and  is  used  as  a  caustic. 

The  chromates,  especially  potassium  dichromate  (q.  v.),  are  irri- 
tants, and  have  a  distinctly  poisonous  action  as  well.  Workmen 
handling  the  dichromate  are  liable  to  a  form  of  chronic  poisoning. 

In  acute  chromium  poisoning,  emetics,  and  subsequently  magne- 
sium carbonate  in  milk,  are  to  be  given. 


MANGANESE. 

=Mn— Atomic   weight=55  (O= 16:55;   H=l:54.56)  —  Mo- 
lecular weight=HO  (l)—Sp.  gr.=7. 138-7. 206. 

Occurs  chiefly  in  pyrolusite,  MnO2,  hausmanite,  Mn3O4,  braunite, 
Mn2O3,  and  manganite,  Mn2O3,  H2O.  A  hard,  grayish,  brittle  metal; 
fusible  with  difficulty;  obtained  by  reduction  of  its  oxids  by  C  at  a 


MANGANESE  149 

white  heat.  It  is  not  readily  oxidized  by  cold,  dry  air;  but  is  super- 
ficially oxidized  when  heated.  It  decomposes  H2O,  liberating  H,  and 
dissolves  in  dilute  acids. 

Oxids. — Manganese  forms  six  oxids,  or  compounds  representing 
them:  Manganous  oxid,  MnO;  manganoso-manganic  oxid,  Mn3C>4; 
manganic  oxid,  M^Oa;  permanganic  oxid,  MnO2,  and  permanganic 
anhydrid,  M^O?,  are  known  free.  Manganic  anhydrid,  MnO3,  has 
not  been  isolated.  MnO  and  Mn2O3  are  basic;  Mn3(>4  and  MnO2  are 
indifferent  oxids;  and  MnO3  and  Mn2(>7  are  anhydrids,  corresponding 
to  the  manganates  and  permanganates. 

Permanganic  oxid — Manganese  dioxid,  or  lilack  oxid — Mangani 
oxidum  nigrum  (U.  S.);  Manganesii  ox.  nig.  (Br.) — MnO2 — 86 — 
exists  in  nature  as  pyrolusite,  the  principal  ore  of  manganese,  in 
steel  gray,  or  brownish  black,  imperfectly  crystalline  masses. 

At  a  red  heat  it  loses  12  per  cent,  of  O:  3MnO2— Mn3O4+O2;  and 
at  a  white  heat,  a  further  quantity  of  O  is  given  off:  2Mn304= 
6MnO+O2.  Heated  with  H2SO4,  it  gives  off  O,  and  forms  manga- 
noussulfate:  2MnO2+2H2SO4=:2MnSO4+2H2O+O2.  With  HC1  it 
yields  manganous  chlorid,  H2O  and  Cl:  Mn02+4HCl  =  MnCl2+ 
2H20+C12.  It  is  not  acted  on  by  HNO3. 

Chlorids. — Two  chlorids  of  Mn  are  known:  manganous  chlorid, 
MnCl2,  a  pink,  deliquescent,  soluble  salt,  occurring,  mixed  with  ferric 
chlorid,  in  the  waste  liquid  of  the  preparation  of  01;  and  manganic 
chlorid,  Mn2Cle. 

Salts  of  Manganese. — Manganese  forms  two  series  of  salts: 
Manganous  salts,  containing  Mn";  and  manganic  salts,  containing 
(Mn2)vi;  the  former  are  colorless  or  pink,  and  soluble  in  water;  the 
latter  are  unstable. 

Manganous  Sulfate — Mangani  sulfas  (U.  S.) — MnSCX+wAq — 
150+^18 — is  formed  by  the  action  of  H2SO4  on  MnO2.  Below  6° 
(42.8°  F.)  it  crystallizes  with  7  Aq,  and  is  isomorphous  with  ferrous 
sulfate;  between  7°-20°  (44.6°-68°  F.)  it  forms  crystals  with  5  Aq, 
and  is  isomorphous  with  cupric  sulfate;  between  20°-30°  (68°-86°  F.) 
it  crystallizes  with  4  Aq.  It  is  rose -colored,  darker  as  the  proportion 
of  Aq  increases,  soluble  in  H20,  insoluble  in  alcohol.  With  the 
alkaline  sulfates  it  forms  double  salts,  with  6  Aq. 

Analytical  Characters.— MANGANOUS. — (1)  Potash:  white  ppt., 
turning  brown.  (2)  Alkaline  carbonates:  white  ppts.  (3)  Ammo- 
nium sulf  hydrate:  flesh -colored  ppt.,  soluble  in  acids,  sparingly  soluble 
in  excess  of  precipitant.  (4)  Potassium  ferrocyanid:  faintly  reddish 
white  ppt.,  in  neutral  solution;  soluble  in  HC1.  (5)  Potassium 
cyanid:  rose -colored  ppt.  forming  brown  solution  with  excess. 

MANGANIC.— (1)  H2S:  ppt.  of  sulfur.  (2)  Ammonium  sulf  hydrate: 
flesh -colored  ppt.  (3)  Potassium  ferrocyanid:  greenish  ppt.  (4)  Po- 


150  MANUAL    OF    CHEMISTRY 

tassium  ferricyanid:  brown  ppt.  (5)  Potassium  cyanid:  light  brown 
ppt. 

MANGANATES— are  green  salts,  whose  solutions  are  only  stable  in 
presence  of  excess  of  alkali,  and  turn  brown  when  diluted  and  acidu- 
lated. 

PERMANGANATES — form  red  solutions,  which  are  decolorized  by 
862,  other  reducing  agents,  and  many  organic  substances. 


IRON. 

Symbol  =  Fe  (Ferrum) — Atomic  weight=56  (0  =  16:56;  H= 
1:55.56)—  Molecular  weight=lll.S  (1)—Sp.  gr.  =7. 25-7. 9— Fuses  at 
1600°  (2912°  F.)— Name  from  the  Saxon,  iren. 

Occurrence. — Free,  in  small  quantity  only,  in  platinum  ores  and 
meteorites.  As  Fe20a  in  red  haematite  and  specular  iron;  as  hydrates 
of  Fe2Oa  in  brown  haematite  and  oolitic  iron;  as  FeaCKt  in  magnetic 
iron;  as  FeCOs  in  spathic  iron,  clay  ironstone  and  bog  ore;  and  as 
Fe§2  in  pyrites.  It  is  also  a  constituent  of  most  soils  and  clays, 
exists  in  many  mineral  waters,  and  in  the  red  blood  pigment  of  ani- 
mals. 

Preparation. — In  working  the  ores,  reduction  is  first  effected  in  a 
blast  furnace,  into  which  alternate  layers  of  ore,  coal  and  limestone 
are  fed  from  the  top,  while  air  is  forced  in  from  below.  In  the  lower 
part  of  the  furnace  C(>2  is  produced,  at  the  expense  of  the  coal; 
higher  up  it  is  reduced  by  the  incandescent  fuel  to  CO,  which,  at  a 
still  higher  point,  reduces  the  ore.  The  fused  metal,  so  liberated, 
collects  at  the  lowest  point,  under  a  layer  of  slag;  and  is  drawn  off  to 
be  cast  as  pig  iron.  This  product  is  then  purified,  by  burning  out 
impurities,  in  the  process  known  as  puddling. 

Pure  iron  is  prepared  by  reduction  of  ferrous  chlorid,  or  of  ferric 
oxid,  by  H  at  a  temperature  approaching  redness. 

Varieties. — Cast  iron  is  a  brittle,  white  or  gray,  crystalline  metal, 
consisting  of  Fe  89-90%;  C  1-4.5%;  and  Si,  P,  S,  and  Mn.  As  pig 
iron,  it  is  the  product  of  the  blast-furnace. 

Wrought,  or  bar  iron,  is  a  fibrous,  tough  metal,  freed  in  part  from 
the  impurities  of  cast  iron,  by  refining  and  puddling . 

Steel  is  Fe  combined  with  a  quantity  of  C,  less  than  that  existing 
in  cast  iron,  and  greater  than  that  in  bar  iron.  It  is  prepared  by 
cementation;  which  consists  in  causing  bar  iron  to  combine  with  C; 
or  by  the  Bessemer  method;  which,  as  now  used,  consists  in  burning 
the  C  out  of  molten  cast  iron,  to  which  the  proper  proportion  of  C  is 
then  added  in  the  shape  of  spiegel  eisen,  an  iron  rich  in  Mn  and  C. 

The  purest  forms  of  commercial  iron  are  those  used  in  piano- 


IRON  151 

strings,  the  teeth  of  carding  machines  and  electro  magnets;  known  as 
soft  iron. 

Reduced  iron — Ferrum  reductum  (U.  S.) — Per.  redactum  (Br.) 
— is  Fe,  more  or  less  mixed  with  Fe2O3  and  Fe3O4,  obtained  by  heat- 
ing Fe2O3  in  H. 

Properties. — Physical. —  Pure  iron  is  silver  white,  quite  soft ; 
crystallizes  in  cubes  or  octahedra.  Wrought  iron  is  gray,  hard,  very 
tenacious,  fibrous,  quite  malleable  and  ductile,  capable  of  being 
welded,  highly  magnetic,  but  only  temporarily  so.  Steel  is  gray,  very 
hard  and  brittle  if  tempered,  soft  and  tenacious  if  not,  permanently 
magnetic. 

Chemical. — Iron  is  not  altered  by  dry  air  at  the  ordinary  tem- 
perature. At  a  red  heat  it  is  oxidized.  In  damp  air  it  is  converted 
into  a  hydrate,  iron  rust.  Tinplate  is  sheet  iron,  coated  with  tin; 
galvanized  iron  is  coated  with  zinc,  to  preserve  it  from  the  action  of 
damp  air. 

Iron  unites  directly  with  01,  Br,  I,  S,  N,  P,  As,  and  Sb.  It  dis- 
solves in  HC1  as  ferrous  chlorid,  while  H  is  liberated.  Heated  with 
strong  H2SO4,  it  gives  off  SO2;  with  dilute  H2S04,  H  is  given  off  and 
ferrous  sulfate  formed.  Dilute  HNO3  dissolves  Fe,  but  the  concen- 
trated acid  renders  it  passive,  when  it  is  not  dissolved  by  either  con- 
centrated or  dilute  HNO3,  until  the  passive  condition  is  destroyed  by 
contact  with  Pt,  Ag  or  Cu,  or  by  heating  to  40°  (104°  F.) . 

Compounds  of  Iron. — Oxids. — Three  oxids  of  iron  exist  free: 
FeO;  Fe2O3;  Fe3O4. 

Ferrous  Oxid. — Protoxid  of  iron — FeO — 72 — is  formed  by  heating 
Fe2O3  in  CO  or  C02. 

Ferric  Oxid. — Sesquioxid  or  peroxid  of  iron — Colcothar — Jeweler's 
rouge — Venetian  red — Fe2O3 — 160 — occurs  in  nature  (see  above),  and 
is  formed  when  ferrous  sulfate  is  strongly  heated,  as  in  the  manu- 
facture of  pyrosulfuric  acid.  It  is  a  reddish,  amorphous  solid,  is  a 
weak  base,  and  is  decomposed  at  a  white  heat  into  O  and  Fe304. 

Magnetic  Oxid- — Black  oxid — Ferri  oxidum  magneticum  (Br.)— 
Fe3O4 — 232 — is  the  natural  loadstone,  and  is  formed  by  the  action  of 
air,  or  steam,  upon  iron  at  high  temperatures.  It  is  probably  a  com- 
pound of  ferrous  and  ferric  oxids  (FeO,  Fe2O3),  as  acids  produce  with 
it  mixtures  of  ferrous  and  ferric  salts. 

Hydrates. — Ferrous. — When  a  solution  of  a  ferrous  salt  is  de- 
composed by  an  alkaline  hydroxid,  a  greenish -white  hydroxid, 
FeH202,  is  deposited;  which  rapidly  absorbs  O  from  the  air,  with 
formation  of  ferric  hydroxid. 

Ferric. — When  an  alkali  is  added  to  a  solution  of  a  ferric  salt,  a 
brown,  gelatinous  precipitate  is  formed,  which  is  the  normal  ferric 
hydroxid  (FehHeOe^  Ferri  peroxidum  hydratum  (U.  S.)  ;  Fer. 


l.VJ  MANUAL    OF    CHEMISTRY 

perox.  humidum  (Br.).  It  is  not  formed  in  the  presence  of  fixed 
organic  acids,  or  of  sugar  in  sufficient  quantity.  If  preserved  under 
H2O,  it  is  partly  oxidized,  forming  an  oxy hydrate  which  is  incapable 
of  forming  ferrous  arsenate  with  As-jOs. 

If  the  hydroxid  (Fe2)  H606,  be  dried  at  100°  (212°  F.)f  it  loses 
•J1I,O,  and  is  converted  into  (Fe2)O2,  H202,  which  is  the  Ferri  peroxi- 
dum  hydnttum  (Br.). 

If  the  normal  hydroxid  be  dried  in  vacuo,  it  is  converted  into 
(Fe2)2H6O9,  and  this,  when  boiled  for  some  hours  with  H2O,  is  con- 
verted into  the  colloid  or  modified  hydrate  (Fe2)H2O4  (?),  which  is 
brick-red  in  color,  almost  insoluble  in  HNO3  and  HC1,  gives  no 
Prussian  blue  reaction,  and  forms  a  turbid  solution  with  acetic  acid. 
If  recently  precipitated  ferric  hydroxid  be  dissolved  in  solution  of 
ferric  chlorid  or  acetate,  and  subjected  to  dialysis,  almost  all  the  acid 
passes  out,  leaving  in  the  dialyzer  a  dark  red  solution,  which  prob- 
ably contains  this  colloid  hydrate,  and  which  is  instantly  coagulated 
by  a  trace  of  H2S(>4,  by  alkalies,  many  salts,  and  by  heat;  dialyzed 
iron. 

Ferric  Acid. — H2FeO4. — Neither  the  free  acid  nor  the  oxid,  FeOs, 
is  known  in  the  free  state;  the  ferrates,  however,  of  Na,  K,  Ba,  Sr, 
and  Ca  are  known. 

Sulfids. — Ferrous  Sulfid — Protosulfid  of  iron — FeS  —  88  —  is 
formed  : 

(1)  By  heating  a  mixture  of  finely -divided  Fe  and  S  to  redness; 
(2)  by  pressing  roll -sulfur  on  white-hot  iron;  (3)  in  a  hydrated  con- 
dition, FeS,  H2O,  by  treating  a  solution  of  a  ferrous  salt  with  an 
alkaline  sulf hydrate. 

The  dry  sulfid  is  a  brownish,  brittle,  magnetic  solid,  insoluble  in 
H2O,  soluble  in  acids  with  evolution  of  H2S.  The  hydrate  is  a  black 
powder,  which  absorbs  ,O  from  the  air,  turning  yellow,  by  formation 
of  Fe2(>3,  and  liberation  of  S.  It  occurs  in  the  faeces  of  persons 
taking  chalybeate  waters  or  preparations  of  iron. 

Ferric  Sulfid  —  Sesquisulfid — Fe2Ss — 208 — occurs  in  nature  in 
copper  pyrites,  and  is  formed  when  the  disulfid  is  heated  to  redness. 

Ferric  Disulfid — FeS2 — 120 — occurs  in  the  white  and  yellow  Mar- 
tial pyrites,  used  in  the  manufacture  of  H2SO4.  When  heated  in  air, 
it  is  decomposed  into  S02  and  magnetic  pyrites  :  3FeS2+2O2=FesS4+ 
2S02. 

Chlorids.  —  Ferrous  Chlorid  —  Protochlorid  — FeCl2 — 126.9  —  is 
produced:  (1)  by  passing  dry  HC1  over  red-hot  Fe;  (2)  by  heating 
ferric  chlorid  in  H;  (3)  as  a  hydrate,  FeCl2,  4H2O,  by  dissolving 
Fe  in  HC1. 

The  anhydrous  compound  is  a  yellow,  crystalline,  volatile,  and 
very  soluble  solid.  The  hydrated  is  in  greenish,  oblique  rhombic 


IRON  153 

prisms,  deliquescent  and  very  soluble  in  H^O  and  alcohol.  When 
heated  in  air  it  is  converted  into  ferric  chlorid,  and  an  oxy- 
chlorid. 

Ferric  Chlorid — Sesquichlorid — Perchlorid — Ferri  chloridum  (U. 
S.) — Fe2Cl6— 324.7 — is  produced,  in  the  anhydrous  form,  by  heating 
Fe  in  Cl.  As  a  hydrate,  Fe2Cl6,  4H20,  or  Fe2Cl6,  6H2O,  it  is  formed: 
(1)  by  solution  of  the  anhydrous  compound;  (2)  by  dissolving  Fe  in 
aqua  regia;  (3)  by  dissolving  ferric  hydroxid  in  HC1 ;  (4)  by  the 
action  of  Cl  or  of  HNO3  on  solution  of  ferrous  chlorid.  It  is  by  the 
last  method  that  the  pharmaceutical  product  is  obtained. 

The  anhydrous  compound  forms  reddish -violet,  crystalline  plates, 
very  deliquescent.  The  hydrates  form  yellow,  nodular,  imperfectly 
crystalline  masses,  or  rhombic  plates,  very  soluble  in  H2O,  soluble  in 
alcohol  and  ether.  In  solution,  it  is  converted  into  FeCl2  by  reducing 
agents.  The  Liq.  ferri  chloridi  (U.  S.)=Liq.  fer.  perchloridi  (Br.) 
is  an  aqueous  solution  of  this  compound,  containing  excess  of  acid. 
The  Tinct.  fer.  chlor.  (U.  S.)  and  Tinct.  fer.  perchl.  (Br.)  are  the 
solution,  diluted  with  alcohol,  and  contain  ethyl  chlorid  and  ferrous 
chlorid. 

Bromids. — Ferrous  Bromid — FeBr2 — 215.9 — is  formed  by  the 
action  of  Br  on  excess  of  Fe,  in  presence  of  H2O. 

Ferric  Bromid — Fe2Br6 — 591.7 — is  prepared  by  the  action  of  ex- 
cess of  Br  on  Fe. 

lodids.— Ferrous  lodid— Ferri  iodidum  (U.  S. ;  Br.)—FeI2— 309.7 
—is  obtained,  with  4H2O,  by  the  action  of  I  upon  excess  of  Fe  in  the 
presence  of  warm  H20.  When  anhydrous,  it  is  a  white  powder; 
hydrated,  it  is  in  green  crystals.  In  air  it  is  rapidly  decomposed, 
more  slowly  in  the  presence  of  sugar. 

Ferric  lodid — Fe2I6 — 873 — is  formed  by  the  action  of  excess  of  I 
on  Fe. 

Salts  of  Iron.— Sulfates. — Ferrous  Sulfate— Protosulfate — Green 
vitriol -Copperas— Ferri  sulfas  (U.  S.  ;  Br.)— FeSO4+7Aq— 152+ 
126— is  formed  :  (1)  by  oxidation  of  the  sulfid,  Fe3S4,  formed  in 
the  manufacture  of  H2SO4;  (2)  by  dissolving  Fe  in  dilute  H2SO4. 

It  forms  green,  efflorescent,  oblique  rhombic  prisms,  quite  soluble 
in  H2O,  insoluble  in  alcohol.  It  loses  6  Aq  at  100°  (212°  F.) 
(Ferr.  sulf.  exsiccatus,  U.  S.) ;  and  the  last  Aq  at  about  300°  (572° 
F.).  At  a  red  heat  it  is  decomposed  into  Fe2O3;  SO2  and  SO3.  By 
exposure  to  air  it  is  gradually  converted  into  a  basic  ferric  sulf  ate, 
(Fe2)(S04)3,  5Fe203. 

Ferric  Sulfates  are  quite  numerous,  and  are  formed  by  oxidations 
of  ferrous  sulf  ate  under  different  conditions.  The  normal  sulf  ate, 
(Fe2)(SO4)3,  is  formed  by  treating  solution  of  FeS04  with  HNO3, 
and  evaporating,  after  addition  of  one  molecule  of  H2S04  for  each 


154  MANUAL    OF    CHEMISTRY 

two  molecules  of  FeS04.     The  Liq.  fer.  tersulfatis  (U.  S.),  contains 
this  salt.     It  is  a  yellowish  white,  amorphous  solid. 

Of  the  many  basic  ferric  sulfates,  the  only  one  of  medical  in- 
terest is  Monsel's  salt,  5(Fe2)  (SO4)3+4Fe2O3,  which  exists  in  the 
Liq.  ferri  subsulfatis  (U.  S.)  and  Liq.  fer.  persulfatis  (Br.).  Its 
solution  is  decolorized,  and  forms  a  white  deposit  with  excess  of 

H2SO4. 

Nitrates.— Ferrous  Nitrate— Fe  (NO3)2— 179.1— a  greenish,  un_ 
stable  salt,  formed  by  double  decomposition  between  barium  nitrate 
and  ferrous  sulfate;  or  by  the  action  of  HNOs  on  FeS. 

Ferric  Nitrates.  —  The  normal  nitrate — (Fe2)(NO3)e — 484.2 — is 
obtained  in  solution  by  dissolving  Fe  in  HNOs  of  sp.  gr.  1.115:  or 
by  dissolving  ferric  hydroxid  in  HNO3.  It  therefore  exists  in  the 
Liq.  ferri  nitratis  (U.  S.).  It  crystallizes  in  rhombic  prisms  with  18 
Aq,  or  in  cubes  with  12  Aq. 

Several  basic  nitrates  are  known,  all  of  which  are  uncrystallizable, 
and  by  their  presence  (as  when  Fe  is  dissolved  in  HNOs  to  satura- 
tion) prevent  the  crystallization  of  the  normal  salt. 

Phosphates. — Triferrous  Phosphate — FesfPC^h — 358. — A  white 
precipitate,  formed  by  adding  disodic  phosphate  to  a  solution  of  a 
ferrous  salt,  in  presence  of  sodium  acetate.  By  exposure  to  air  it 
turns  blue;  apart  being  converted  into  ferric  phosphate.  The/ern 
phosphas  (Br.)  is  such  a  mixture  of  the  two  salts.  It  is  insoluble  in 
H2O ;  sparingly  soluble  in  E^O  containing  carbonic  or  acetic  acid. 

It  is  probably  this  phosphate,  capable  of  turning  blue,  which 
sometimes  occurs  in  the  lungs  in  phthisis,  in  blue  pus,  and  in  long- 
buried  bones. 

Ferric  Phosphate — (Fe2)(PO4)2 — 302 — is  produced  by  the  action 
of  an  alkaline  phosphate  on  ferric  chlorid.  It  is  soluble  in  HC1, 
HNOs,  citric  and  tartaric  acids,  insoluble  in  phosphoric  acid  and  in 
solution  of  hydrosodic  phosphate.  The  ferri  phosphas  (U.  S.)  is  a 
compound,  or  mixture  of  this  salt  with  disodic  citrate,  which  is  sol- 
uble in  water. 

There  exist  quite  a  number  of  basic  ferric  phosphates. 

Ferric  Pyrophosphate—  (Fe2) 2^207)3— 746— is  precipitated  by 
decomposition  of  a  solution  of  a  ferric  compound  by  sodium  pyro- 
phosphate;  an  excess  of  the  Na  salt  dissolves  the  precipitate  when 
warmed,  and,  on  evaporation,  leaves  the  scales  of  a  double  salt, 
(Fe2)2  (P2O7)3,  Na8(P2O7)2+20  Aq. 

The  ferri  pyrophosphas  (U.  S.)  is  a  mixture  of  ferric  pyrophos- 
phate,  trisodic  citrate,  and  ferric  citrate. 

Acetates.— Ferrous  Acetate— Fe(C2H3O2)2— 174— is  formed  by 
decomposition  of  ferrous  sulfate  by  calcium  acetate,  in  soluble,  silky 
needles. 


IRON  155 

Ferric  Acetates. — The  normal  salt  (Fe2)(C2H3O2)6,  is  obtained  by 
adding  slight  excess  of  ferric  sulfate  to  lead  acetate,  and  decanting 
after  twenty -four  hours.  It  is  dark -red,  uncrystallizable,  very  sol- 
uble in  alcohol,  and  in  H2O.  If  its  solution  be  heated  it  darkens 
suddenly,  gives  off  acetic  acid,  and  contains  a  basic  acetate.  When 
boiled,  it  loses  all  its  acetic  acid,  and  deposits  ferric  hydrate.  When 
heated  in  closed  vessels  to  100°  (212°  F.),  and  treated  with  a  trace  of 
mineral  acid,  it  deposits  the  modified  ferric  hydrate. 

Ferrous  Carbonate — FeCO3 — Spathic  iron — clay  ironstone — log 
ore — 116 — occurs  as  an  ore  of  iron,  and  is  obtained,  in  a  hydrated 
form,  by  adding  an  alkaline  carbonate  to  a  ferrous  salt.  It  is  a 
greenish,  amorphous  powder,  which  on  exposure  to  air  turns  red  by 
formation  of  ferric  hydrate;  a  change  which  is  retarded  by  the  pres- 
ence of  sugar,  hence  the  addition  of  that  substance  in  the  ferri  car- 
bonas  saccharatus  (U.  S.;  Br.).  It  is  insoluble  in  pure  H2O,  but 
soluble  in  H2O  containing  carbonic  acid,  probably  as  ferrous  bicar- 
bonate, H2Fe( CO3)2,  in  which  form  it  occurs  in  chalybeate  waters. 

Ferrous  Lactate— Ferri  Lactas  (U.  S.)— Fe(C3H5O3)2+3  Aq— 
234+54 — is  formed  when  iron  filings  are  dissolved  in  lactic  acid.  It 
crystallizes  in  greenish  yellow  needles;  soluble  in  H20;  insoluble  in 
alcohol;  permanent  in  air  when  dry. 

Ferrous  Oxalate— Ferri oxalas  (U.  S.)  FeC2O4+2Aq— 144+36— is 
a  yellow,  crystalline  powder;  sparingly  soluble  in  EkO;  formed  by 
dissolving  iron  filings  in  solution  of  oxalic  acid. 

Tartrates  —  Ferrous  Tartrate  —  FeC4H4O6+2Aq  —  204+ 36.  —  A 
white,  crystalline  powder;  formed  by  dissolving  Fe  in  hot  concen- 
trated solution  of  tartaric  acid. 

Ferric  Tartrate— Fe2( C4H4O6) 3+ 3Aq— 556+54.—  A  dirty  yellow, 
amorphous  mass,  obtained  by  dissolving  recently  precipitated  ferric 
hydroxid  in  tartaric  acid  solution,  and  evaporating  below  59°  (122° 
F.). 

A  number  of  double  tartrates,  containing  the  group  (Fe&z)"  are 
also  known.  Such  are:  Ferrico-ammonic  tartrate=ferri  et  ammonii 
tartras  (U.  S.),  (C4H4O6)2(Fe2O2),(NH4)2+4Aq,  and  Ferrico-potassic 
tartrate  =  ferri  et  potassii  tartras  (U.  S.),  (C4H406)2(Fe2O2)K2. 
They  are  prepared  by  dissolving  recently  precipitated  ferric  hydroxid 
in  hot  solutions  of  the  hydro -alkaline  tartrate.  They  only  react  with 
ferrocyanids  and  thiocyanates  after  addition  of  a  mineral  acid. 

Citrates. — Ferric  Citrate— Ferri  citras  (U.  S.)— (Fe2)  (C6H5O7)2+ 
6Aq— 490+108— is  in  garnet -colored  scales,  obtained  by  dissolving 
ferric  hydrate  in  solution  of  citric  acid,  and  evaporating  the  solution 
at  about  60°  (140°  F.).  It  loses  3Aq  at  120°  (248°  F.),  and  the 
remainder  at  150°  (302°  F.).  If  a  small  quantity  of  ammonium 
hydroxid  be  added,  before  the  evaporation,  the  product  consists  of 


156  MANUAL    OF    CHEMISTRY 

the  modified   citrater=ferri  et  ammonii  citras  (U.  S.),  which  only 
reacts  with  potassium  ferrocyanid  after  addition  of  HOI. 

The  various  citrates  of  iron  and  alkaloids  are  not  definite  com- 
pounds. 

Ferric    Ferrocyanid — Prussian   blue — (Fe2)2(FeC6N6)3+18Aq  — 
860+324 — is  a  dark -blue  precipitate,  formed  when  potassium  ferro- 
cyanid is  added  to  a  ferric  salt.     It  is  insoluble  in  H2O,  alcohol  and 
dilute  acids  ;  soluble  in  oxalic  acid  solution  (blue  ink) .      Alkalies 
turn  it  brown. 

Ferrous  Ferricyanid — Turnbull's  blue — Fe3(Fe2Ci2Ni2)+/iAq— 
592+nl8 — is  a  dark  blue  substance  produced  by  the  action  of  potas- 
sium ferricyanid  on  ferrous  salts.  Heated  in  air  it  is  converted  into 
Prussian  blue  and  ferric  oxid. 

Analytical  Characters. — FERROUS — Are  acid;  colorless  when  an- 
hydrous, pale  green  when  hydrated;  oxidized  by  air  to  basic  ferric 
compounds.  (1)  Potash:  greenish  white  ppt.;  insoluble  in  excess; 
changing  to  green  or  brown  in  air.  (2)  Ammonium  hydroxid; 
greenish  ppt.;  soluble  in  excess;  not  formed  in  presence  of  ammo- 
niacal  salts.  (3)  Ammonium  sulfhydrate  :  black  ppt.;  insoluble  in 
excess;  soluble  in  acids.  (4)  Potassium  ferrocyanid  (in  absence  of 
ferric  salts) :  white  ppt.;  turning  blue  in  air.  (5)  Potassium  ferri- 
cyanid: blue  ppt.;  soluble  in  KHO;  insoluble  in  HC1. 

FERRIC — Are  acid,  and  yellow  or  brown.  (1)  Potash,  or  ammo- 
nium hydroxid:  voluminous,  red-brown  ppt.;  insoluble  in  excess. 
(2)  Hydrogen  sulfid,  in  acid  solution  :  milky  ppt.  of  sulfur;  ferric 
reduced  to  ferrous  compound.  (3)  Ammonium  sulfhydrate  :  black 
ppt.  ;  insoluble  in  excess  ;  soluble  in  acids.  (4)  Potassium  ferro- 
cyanid: dark  blue  ppt.;  insoluble  inHCl;  soluble  in  KHO.  (5)  Po- 
cassium  thiocyanate:  dark -red  color;  prevented  by  tartaric  or  citric 
acid  ;  discharged  by  mercuric  chlorid.  (6)  Tannin  :  blue -black 
color. 


III.     URANIUM   GROUP. 

URANIUM. 

Symbol=Ur— Atomic  iveight=239.5  (0=16:239.5;  H=l:237.6) 
— 8p.  gr=lS  A— Discovered  by  Klaproth  (1789). 

This  element  is  usually  classed  with  Fe  and  Cr,  or  with  Ni  and 
Co.  It  does  not,  however,  form  compounds  resembling  the  ferric;  it 
forms  a  series  of  well-defined  uranates,  and  a  series  of  compounds  of 
the  radical  uranyl  (UO)'.  Standard  solutions  of  its  acetate  or 
nitrate  are  used  for  the  quantitative  determination  of  H3PO4. 


LEAD  157 


IV.     LEAD   GROUP. 

LEAD. 

Sijmbol=P\)  (Plumbum)— Atomic  weight  =  207  (0—16:206.9; 
H=l:205.06)—  Molecular  weight=±l±  (1)—Sp.  gr. =11 .445— Fuses 
at  325°  (617°  F.)— -Name  from  loed— heavy  (Saxon). 

Lead  is  usually  classed  with  Cd,  Bi,  or  Cu  and  Hg.  It  differs, 
however,  from  Bi  in  being  bivalent  or  quadrivalent,  but  not  triva- 
lent,  and  in  forming  no  compounds  resembling  those  of  bismuthyl 
(BiO) ;  from  Cd,  in  the  nature  of  its  O  compounds;  and  from  Cu  and 
Hg  in  forming  no  compounds  similar  to  the  mercurous  and  cuprous 
salts.  Indeed,  the  nature  of  the  Pb  compounds  is  such  that  the 
element  is  best  classed  in  a  group  by  itself,  which  finds  a  place  in 
this  class  by  virtue  of  the  existence  of  potassium  plumbate. 

Occurrence. — Its  most  abundant  ore  is  galena,  PbS.  It  also 
occurs  in  white  lead  ore,  PbCOs,  in  anglesite,  PbS04,  and  in  horn 
lead,  PbCl2. 

Preparation. — Galena  is  first  roasted  with  a  little  lime.  The  mix- 
ture of  PbO,  PbS,  and  PbSO4  obtained,  is  strongly  heated  in  a  rever- 
beratory  furnace,  when  SO2  is  driven  off.  The  impure  work  lead,  so 
formed,  is  purified  by  fusion  in  air,  and  removal  of  the  film  of  oxids 
of  Sn  and  Sb.  If  the  ore  be  rich  in  Ag,  that  metal  is  extracted,  by 
taking  advantage  of  the  greater  fusibility  of  an  alloy  of  Pb  and  Ag, 
than  of  Pb  alone;  and  subsequent  oxidation  of  the  remaining  Pb. 

Properties. — Physical. — It  is  a  bluish  white  metal;  brilliant  upon 
freshly  cut  surfaces;  very  soft  and  pliable;  not  very  malleable  or 
ductile;  crystallizes  in  octahedra;  a  poor  conductor  of  electricity;  a 
better  conductor  of  heat.  When  expanded  by  heat  it  does  not,  on 
cooling,  return  to  its  original  volume. 

Chemical. — When  exposed  to  air  it  is  oxidized,  more  readily  and 
completely  at  high  temperatures.  The  action  of  H2O  on  Pb  varies 
with  the  conditions.  Pure  unaerated  H2O  has  no  action  upon  it.  By 
the  combined  action  of  air  and  moisture  Pb  is  oxidized,  and  the  oxid 
dissolved  in  the  H2O,  leaving  a  metallic  surface  for  the  continuance 
of  the  action.  The  solvent  action  of  H2O  upon  Pb  is  increased,  owing 
to  the  formation  of  basic  salts,  by  the  presence  of  nitrogenized  organic 
substances,  nitrates,  nitrites,  and  chlorids.  On  the  other  hand,  car- 
bonates, sulfates,  and  phosphates,  by  their  tendency  to  form  insoluble 
coatings,  diminish  the  corroding  action  of  H2O.  Carbonic  acid  in 
small  quantity,  especially  in  presence  of  carbonates,  tends  to  preserve 
Pb  from  solution,  while  H2O  highly  charged  with  it  (soda  water) 
dissolves  the  metal  readily.  Lead  is  dissolved,  as  a  nitrate,  by  HNOa. 


158  MANUAL    OF    CHEMISTRY 

H2SO4,  when  cold  and  moderately  concentrated,  does  not  affect  it;  but, 
when  heated,  dissolves  it  the  more  readily  as  the  acid  is  more  concen- 
trated. It  is  attacked  by  HC1  of  sp.  gr.  1.12,  especially  if  heated. 
Acetic  acid  dissolves  it  as  acetate,  or,  in  the  presence  of  CO2,  con- 
verts it  into  white  lead. 

Oxids. — Lead  Monoxid — Protoxid — Massicot — Litharge — Plum- 
bi  oxidum  (U.  S.;  Br.)—PbO— 222.9— is  prepared  by  heating  Pb,  or 
its  carbonate,  or  nitrate,  in  air.  If  the  product  have  been  fused,  it  is 
litharge  ;  if  not,  massicot.  It  forms  copper -colored,  mica-like  plates, 
or  a  yellow  powder;  or  crystallizes,  from  its  solution  in  soda  or 
potash,  in  white,  rhombic  dodecahedra,  or  in  rose -colored  cubes.  It 
fuses  near  a  red  heat,  and  volatilizes  at  a  white  heat;  sp.  gr.  9.277- 
9.5.  It  is  sparingly  soluble  in  H2O,  forming  an  alkaline  solution. 

Heated  in  air  to  300°  (572°  F.)  it  is  oxidized  to  minium.  It  is 
readily  reduced  by  H  or  0.  With  Cl  it  forms  PbCl2  and  O.  It  is  a 
strong  base;  decomposes  alkaline  salts,  with  liberation  of  the  alkali. 
It  dissolves  in  HNOs,  and  in  hot  acetic  acid,  as  nitrate  or  acetate. 
When  ground  up  with  oils  it  saponifies  the  glycerol  ethers,  the  Pb 
combining  with  the  fatty  acids  to  form  Pb  soaps,  one  of  which,  lead 
oleate,  is  the  emplastrum  plumbi  (U.  S.;  Br.).  It  also  combines 
with  the  alkalies  and  earths  to  form  plumbites.  Calcium  plumbite, 
CaPb2Os,  is  a  crystalline  salt,  formed  by  heating  PbO  with  milk  of 
lime,  and  used  in  solution  as  a,  hair  dye. 

Plumboso-plumbic  Oxid — Red  oxid — Minium — Red  lead — PbsC^ 
—684.7— is  prepared  by  heating  massicot  to  300°  (572°  F.)  in  air. 
It  ordinarily  has  the  composition  PbsC^,  and  has  been  considered  as 
composed  of  PbO2,  2PbO;  or  as  a  basic  lead  salt  of  plumbic  acid, 
PbOaPb,  PbO.  An  orange -colored  variety  is  formed  when  lead  car- 
bonate is  heated  to  300°  (572°  F.). 

It  is  a  bright  red  powder,  sp.  gr.  8.62.  It  is  converted  into  PbO 
when  strongly  heated,  or  by  the  action  of  reducing  agents.  HNOs 
changes  its  color  to  brown,  dissolving  PbO  and  leaving  PbO2.  It  is 
decomposed  by  HC1,  with  formation  of  PbCl2,  H20  and  Cl. 

Lead  Dioxid. — Peroxid,  or  puce  oxid,  or  brown  oxid,  or  Mnoxid  of 
lead — Plumbic  anhydrid — PbO2 — 238.9 — is  prepared,  either  by  dis- 
solving the  PbO  out  of  red  lead  by  dilute  HNO3,  or  by  passing  a 
current  of  Cl  through  H2O,  holding  lead  carbonate  in  suspension. 

It  is  a  dark,  reddish  brown,  amorphous  powder;  sp.  gr.  8.903- 
9.190;  insoluble  in  H2O.  Heated,  it  loses  half  its  O,  and  is  converted 
into  PbO.  It  is  a  valuable  oxidant.  It  absorbs  SO2  to  form  PbS04. 
It  combines  with  alkalies  to  form  plumbates,  M2PbO3. 

Plumbic  Acid.— H2PbO3— 256.9 — forms  crystalline  plates,  at  the 
-h electrode,  when  alkaline  solutions  of  the  Pb  salts  are  decomposed 
by  a  weak  current. 


LEAD  159 

Lead  Sulfid— Galena— PbS— 238.9— exists  in  nature.  It  is  also 
formed  by  direct  union  of  Pb  and  S;  by  heating  PbO  with  S,  or 
vapor  of  C$2;  or  by  decomposing  a  solution  of  a  Pb  salt  by  H2S  or 
an  alkaline  sulfid. 

The  native  sulfid  is  a  bluish  gray,  and  has  a  metallic  luster;  sp.  gr. 
7.58;  that  formed  by  precipitation  is  a  black  powder;  sp.  gr.  6.924. 
It  fuses  at  a  red  heat  and  is  partly  sublimed,  partly  converted  into  a 
subsulfate.  Heated  in  air  it  is  converted  into  PbSO4,  PbO  and  SO2. 
Heated  in  H  it  is  reduced.  Hot  HNO3  oxidizes  it  to  PbSO4.  Hot  HC1 
converts  it  into  PbCl2.  Boiling  H2SO4  converts  it  into  PbSO4  and  SO2. 

Lead  Chlorid— PbCl2— 277.9— is  formed  by  the  action  of  Cl  upon 
Pb  at  a  red  heat;  by  the  action  of  boiling  HC1  upon  Pb,  and  by 
double  decomposition  between  a  lead  salt  and  a  chlorid. 

It  crystallizes  in  plates,  or  hexagonal  needles  ;  sparingly  soluble 
in  cold  H2O,  less  soluble  in  H2O  containing  HC1;  more  soluble  in  hot 
H2O,  and  in  concentrated  HC1. 

Several  oxychlorids  are  known.  Cassel,  Paris,  Verona,  or 
Turner's  yellow  is  PbCl2,  7PbO. 

Lead  lodid— Plumbi  iodidum  (U.  S.;  Br.)—PbI2— 460.09— is 
deposited,  as  a  bright  yellow  powder,  when  a  solution  of  potassium 
iodid  is  added  to  a  solution  of  Pb  salt.  Fused  in  air,  it  is  converted 
into  an  oxyiodid.  Light  and  moisture  decompose  it,  with  liberation 
of  I.  It  is  almost  insoluble  in  H2O,  soluble  in  solutions  of  ammo- 
nium chlorid,  sodium  hyposulfite,  alkaline  iodids,  and  potash. 

Salts  of  Lead. — Nitrates. — Lead  Nitrate — Plumbi  nitras  (U.  S.; 
Br.)—Pb(N03)2— 330.9— is  formed  bysolution  of  Pb,  or  of  its  oxids, 
in  excess  of  HNO3.  It  forms  anhydrous  crystals  ;  soluble  in  H2O. 
Heated,  it  is  decomposed  into  PbO,  O  and  NO2. 

Besides  the  neutral  nitrate,  basic  lead  nitrates  are  known,  which 
seem  to  indicate  the  existence  of  nitrogen  acids  similar  to  those  of 
phosphorus;  Pb3(NO4)2 — orthonitrate  ;  and  Pb2N2O7 — pyronitrate. 

Lead  Sulfate— PbSO4—  302.9— is  formed  by  the  action  of  hot, 
concentrated  H2SO4  on  Pb;  or  by  double  decomposition  between  a 
sulfate  and  a  Pb  salt  in  solution.  It  is  a  white  powder,  almost  insol- 
uble in  H2O,  soluble 'in  concentrated  H2$O4,  from  which  it  is  de- 
posited by  dilution. 

Lead  Chromate — Chrome  yellow — PbCrO4— 323.3— is  formed  by 
decomposing  Pb(NO3)2  with  potassium  chromate.  It  is  a  yellow, 
amorphous  powder,  insoluble  in  H2O,  soluble  in  alkalies. 

Acetates.— Neutral  Lead  Acetate— Salt  of  Saturn— Sugar  of 
Lead— Plumbi  acetas  (U.  S.;  Br.)—Pb(C2H3O2)2-h3Aq— 324.9+54 
—is  formed  by  dissolving  PbO  in  acetic  acid;  or  by  exposing  Pb  in 
contact  with  acetic  acid  to  air. 

It  crystallizes  in  large,  oblique  rhombic  prisms,  sweetish,  with  a 


160  MANUAL    OF    CHEMISTRY 

metallic  after- taste;  soluble  in  H20  and  alcohol;  its  solutions  being 
acid.  In  air  it  effloresces,  and  is  superficially  converted  into  car- 
bonate. It  fuses  at  75.5°  (167.9°  P.);  loses  Aq  and  a  part  of  its 
acid  at  100°  (212°  F.),  forming  the  sesquibasic  acetate,  2[Pb- 
(C2H3O2)2]Pb(OH)2;  at  280°  (536°  F.)  it  enters  into  true  fusion, 
and,  at  a  slightly  higher  temperature,  is  decomposed  into  C02;  Pb, 
and  acetone.  Its  aqueous  solution  dissolves  PbO,  with  formation  of 
basic  acetates. 

Sexbasic  Lead  Acetate— Pb(C2H3O2) OH,  2PbO—  728.7—  is  the 
main  constituent  of  Goulard's  extract=Liq.  plumbi  subacetatis  (U. 
S.;  Br.),  and  is  formed  by  boiling  a  solution  of  the  neutral  acetate 
with  PbO  in  fine  powder.  The  solution  becomes  milky  on  addition 
of  ordinary  H2O,  from  formation  of  the  sulfate  and  carbonate. 

Lead  Carbonate — PbCOs — 266.9 — occurs  in  nature  as  cerusite; 
and  is  formed,  as  a  white,  insoluble  powder,  when  a  solution  of  a  Pb 
compound  is  decomposed  by  an  alkaline  carbonate,  or  by  passing  CO2 
through  a  solution  containing  Pb. 

The  plumbi  carbonas  (U.  S.;  Br.),  or  white  lead  or  ceruse,  is  a 
basic  carbonate  (PbC03)2,  PbH2O2— 774.7— mixed  with  varying  pro- 
portions of  other  basic  carbonates.  It  is  usually  prepared  by  the 
action  of  CO2  on  a  solution  of  the  subacetate,  prepared  by  the  action 
of  acetic  acid  on  Pb  and  PbO.  It  is  a  heavy,  white  powder,  insoluble 
in  H2O,  except  in  the  presence  of  CO2;  soluble  in  acids  with  effer- 
vescence; and  decomposed  by  heat  into  CO2  and  PbO.  White  lead 
enters  into  the  composition  of  almost  all  oil-paints,  being  used  to 
dilute  other  pigments.  The  darkening  of  oil-paintings  is  due  to  the 
formation  of  the  black  lead  sulfid  by  atmospheric  H2S. 

Analytical  Characters.— (1)  Hydrogen  sulfid,  in  acid  solution:  a 
black  ppt.;  insoluble  in  alkaline  sulfids,  and  in  cold,  dilute  acids. 
(2)  Ammonium  sulf hydrate  :  black  ppt.;  insoluble  in  excess.  (3) 
Hydrochloric  acid:  white  ppt.,  in  not  too  dilute  solution;  soluble  in 
boiling  H2O.  (4)  Ammonium  hydroxid  :  white  ppt.;  insoluble  in 
excess.  (5)  Potash:  white  ppt.;  soluble  in  excess,  especially  when 
heated.  (6)  Sulf  uric  acid:  white  ppt.;  insoluble  in  weak  acids,  sol- 
uble in  solution  of  ammonium  tartrate.  (7)  Potassium  iodid:  yel- 
low ppt.;  sparingly  soluble  in  boiling  H2O;  soluble  in  large  excess. 

(8)  Potassium  chromate  :    yellow  ppt.;    soluble   in   KHO    solution. 

(9)  Iron  or  zinc  separate  the  element  from  solution  of  its  salts. 
Action  on  the  Economy. — All  the  soluble  compounds  of  Pb,  and 

those  which,  although  not  soluble,  are  readily  convertible  into  soluble 
compounds  by  H2O,  air,  or  the  digestive  fluids,  are  actively  poi- 
sonous. Some  are  also  injurious  by  their  local  action  upon  tissues 
with  which  they  come  in  contact;  such  are  the  acetate,  and,  in  less 
degree,  the  nitrate. 


LEAD  161 

The  chronic  form  of  lead  intoxication,  painter's  colic,  etc.,  is 
purely  poisonous,  and  is  produced  by  the  continued  absorption  of 
minute  quantities  of  Pb,  either  by  the  skin,  lungs,  or  stomach.  The 
acute  form  presents  symptoms  referable  to  the  local,  as  well  as  to  the 
poisonous,  action  of  the  Pb  salt,  and  is  usually  caused  by  the  inges- 
tion  of  a  single  dose  of  the  acetate  or  carbonate. 

Metallic  Pb,  although  probably  not  poisonous  of  itself,  causes 
chronic  lead -poisoning  by  the  readiness  with  which  it  is  convertible 
into  compounds  capable  of  absorption.  The  principal  sources  of 
poisoning  by  metallic  Pb  are:  the  contamination  of  drinking  water 
which  has  been  in  contact  with  the  metal  (see  p.  73) ;  the  use  of 
articles  of  food,  or  of  chewing  tobacco,  which  has  been  packed  in  tin- 
foil, containing  an  excess  of  Pb;  the  drinking  of  beer  or  other  bev- 
erages which  have  been  in  contact  with  pewter;  or  the  handling  of 
the  metal  and  its  alloys. 

Almost  all  the  compounds  of  Pb  may  produce  painter's  colic. 
The  carbonate,  in  painters,  artists,  manufacturers  of  white  lead,  and 
in  persons  sleeping  in  newly -pain  ted  rooms;  the  oxids,  in  the  manu- 
factures of  glass,  pottery,  sealing-wax,  and  litharge,  and  by  the  use 
of  lead- glazed  pottery;  by  other  compounds,  by  the  inhalation  of  the 
dust  of  cloth  factories,  and  by  the  use  of  lead  hair -dyes. 

Acute  lead -poisoning  is  of  by  no  means  as  common  occurrence  as 
the  chronic  form,  and  usually  terminates  in  recovery.  It  is  caused 
by  the  ingestion  of  a  single  large  dose  of  the  acetate,  subacetate,  car- 
bonate, or  of  red  lead.  In  such  cases  the  administration  of  mag- 
nesium sulfate  is  indicated;  it  enters  into  double  decomposition  with 
Pb  salt  to  form  the  insoluble  PbSO4. 

Lead,  once  absorbed,  is  eliminated  very  slowly,  it  becoming  fixed 
by  combination  with  the  proteins,  a  form  of  combination  which  is 
rendered  soluble  by  potassium  iodid.  The  channels  of  elimination 
are  by  the  perspiration,  urine  and  bile. 

In  the  analysis  for  mineral  poisons  the  major  part  of  the  Pb 
is  precipitated  as  PbS  in  the  treatment  by  H2S.  The  PbS  remains 
upon  the  filter  after  extraction  with  ammonium  sulf hydrate.  It 
is  treated  with  warm  HC1,  which  decolorizes  it  by  transforming 
the  sulfid  into  chlorid.  The  PbCl2  thus  formed  is  dissolved  in  hot 
H^O,  from  which  it  crystallizes  on  cooling.  The  solution  still  con- 
tains PbCl2  in  sufficient  quantity  to  respond  to  the  tests  for  the 
metal. 

Although  Pb  is  not  a  normal  constituent  of  the  body,  the  every- 
day methods  by  which  it  may  be  introduced  into  the  economy,  and 
the  slowness  of  its  elimination,  are  such  as  to  render  the  greatest 
caution  necessary  in  drawing  conclusions  from  the  detection  of  Pb  in 
the  body  after  death. 

11 


162  MANUAL    OF    CHEMISTRY 

• 

V.     BISMUTH   GROUP. 

BISMUTH. 


8ymbol=Bi— Atomic  weight=2Q8.5  (0=16:208.5;  H=l: 206.8)- 
Molecular  weight=±20  (?)  —8p.  grr. =9. 677-9. 935— Fuses  at  268° 
(514.4°  P.). 

This  element  is  usually  classed  with  Sb;  by  some  writers  among 
the  metals,  by  others  in  the  phosphorus  group.  We  are  led  to  class 
Bi  in  our  third  class,  and  in  a  group  alone,  because:  (1)  while  the 
so-called  salts  of  Sb  are  not  salts  of  the  element,  but  of  the  radical 
(SbO)',  anthtwnyl,  Bi  enters  into  saline  combination,  not  only  in  the 
radical  bismuthyl  (BiO)',  but  also  as  an  element;  (2)  while  the  com- 
pounds of  the  elements  of  the  N  group  in  which  those  elements  are 
quinquivalent  are,  as  a  rule,  more  stable  than  those  in  which  they  are 
trivalent,  Bi  is  trivalent  in  all  its  known  compounds  except  one, 
which  is  very  unstable,  in  which  it  is  quinquivalent;  (3)  the  hydrates 
of  the  N  group  are  strongly  acid,  and  their  corresponding  salts  are 
stable  and  well  defined;  but  those  hydrates  of  Bi  which  are  acid  are 
but  feebly  so,  and  the  bismuthates  are  unstable;  (4)  no  compound  of 
Bi  and  H  is  known. 

Occurrence. — Occurs  principally  free,  also  as  Bi2Os  and  Bi2Sa. 

Properties. — Crystallizes  in  brilliant,  metallic  rhombohedra;  hard 
and  brittle. 

It  is  only  superficially  oxidized  in  cold  air.  Heated  to  redness  in 
air,  it  becomes  coated  with  a  yellow  film  of  oxid.  In  H2O,  containing 
CO2,  it  forms  a  crystalline  subcarbonate.  It  combines  directly  with 
Cl,  Br  and  I.  It  dissolves  in  hot  H2SO*  as  sulfate,  and  in  HNOs  as 
nitrate. 

It  is  usually  contaminated  with  As,  from  which  it  is  best  purified 
by  heating  to  redness  a  mixture  of  powdered  bismuth,  potassium 
carbonate,  soap  and  charcoal,  under  a  layer  of  charcoal.  After  an 
hour  the  mass  is  cooled;  the  button  is  separated  and  fused  until  its 
surface  begins  to  be  coated  with  a  yellowish  brown  oxid. 

Oxids. — Four  oxids  are  known:   Bi2O2,  Bi2O3,  Bi2O4,  and  Bi2Os. 

Bismuth  Trioxid  —  Bismuthous  oxid  —  Protoxid — Bi2Oa — 465 — is 
formed  by  heating  Bi,  or  its  nitrate,  carbonate  or  hydrate.  It  is  a 
pale  yellow,  insoluble  powder;  sp.  gr.  8.2;  fuses  at  a  red  heat;  soluble 
in  HC1,  HNOs  and  H2SO4  and  in  fused  potash. 

Hydrates. — Bismuth  forms  at  least  four  hydrates. 

Bismuthous  Hydroxid — BiH3O3 — 259.5 — is  formed,  as  a  white 
precipitate,  when  potash  or  ammonium  hydroxid  is  added  to  a  cold 


BISMUTH  163 

solution  of  a  Bi  salt.     When  dried  it  loses  H^O,  and  is  converted  into 
Bismuthyl  hydroxid  (BiO)HO. 

Bismuthic  acid — (BiO2)HO — 257.5 — is  deposited,  as  a  red  pow- 
der, when  Cl  is  passed  through  a  boiling  solution  of  potash,  holding 
bismuthous  hydroxid  in  suspension.  When  heated  it  is  converted 
into  the  pentoxid,  BizOs. 

Pyrobismuthic  Acid — ILiBi2O7 — 533 — is  a  dark  brown  powder, 
precipitated  from  solution  of  bismuth  nitrate  by  potassium  cyauid. 

Bismuth  Trichlorid — Bismuthous  chlorid — Bids — 314.9 — is  formed 
by  heating  Bi  in  Cl;  by  distilling  a  mixture  of  Bi  and  mercuric 
chlorid;  or  by  distilling  a  solution  of  Bi  in  aqua  regia.  It  is  a  fus- 
ible, volatile,  deliquescent  solid;  soluble  in  dilute  HC1.  On  contact 
with  H2O  it  is  decomposed  with  formation  of  bismuthyl  chlorid, 
(BiO)Cl,  or  pearl  white. 

Bismuth  Nitrate— Bi(NO3)  3+ 5  Aq— 394.5+ 90— obtained  by  dis- 
solving Bi  in  HNO3.  It  crystallizes  in  large,  colorless  prisms;  at 
150°  (302°  F.),  or  by  contact  with  H2O,  it  is  converted  into  bis- 
muthyl nitrate;  at  260°  (500°  F.)  into  Bi2O3. 

Bismuthyl  Nitrate — Trisnitrate  or  subnitrate  of  bismuth — Flake 
white— Bismuth!  subnitras— (U.  S.;  Br.)  —  (BiO)NO3H2O— 304.5— 
is  formed  by  decomposing  a  solution  of  Bi(NOs)3  with  a  large  quantity 
of  H2O.  It  is  a  white,  heavy,  faintly  acid  powder;  soluble  to  a 
slight  extent  in  H2O  when  freshly  precipitated,  the  solution  depositing 
it  again  on  standing.  It  is  decomposed  by  pure  H2O,  but  not  by  E^O 
containing  TOO"  ammonium  nitrate.  It  usually  contains  1  Aq,  which 
it  loses  at  100°  (212°  F.)  Bismuth  subnitrate,  as  well  as  the  sub- 
carbonate,  is  liable  to  contamination  with  arsenic,  which  accompanies 
bismuth  in  its  ores. 

Bismuthyl  Carbonate — Bismuth  subcarbonate —  Bismuthi  sub- 
carbonas  (U.  S.)  Bismuthi  carbonas  (Br.)— (BiO)2CO3H2O  — 527 
—is  a  white  or  yellowish,  amorphous  powder,  formed  when  a  solution 
of  an  alkaline  carbonate  is  added  to  a  solution  of  Bi(NO3)3.  It  is 
odorless,  tasteless,  and  insoluble  in  H2O  and  in  alcohol. 

When  heated  to  100°  (212°  F.),  it  loses  H2O,  and  is  converted 
into  (BiOhCOs.  At  a  higher  temperature  it  is  further  decomposed 
into  Bi2O3  and  CO2. 

Analytical  Characters. — (1)  Water:  white  ppt.,  even  in  presence 
of  tartaric  acid,  but  not  of  HNO3,  HC1,  or  H2SO4.  (2)  Hydrogen 
sulfid:  black  ppt.,  insoluble  in  dilute  acids  and  in  alkaline  sulfids. 
(3)  Ammonium  sulfhydrate:  black  ppt.,  insoluble  in  excess.  (4) 
Potash  soda,  or  ammonia:  white  ppt.,  insoluble  in  excess,  and  in 
tartaric  acid;  turns  yellow  when  the  liquid  is  boiled.  (5)  Potassium 
ferrocyanid:  yellowish  ppt.,  insoluble  in  HC1.  (6)  Potassium  ferri- 
cyanid:  yellowish  ppt.,  soluble  in  HC1.  (7)  Infusion  of  galls: 


164  MANUAL    OF    CHEMISTRY 

orange  ppt.     (8)  Potassium   iodid:    brown  ppt.,  soluble  in  excess. 
(9)  Reacts  with  Reinsch's  test  (q.  v.),  but  gives  no  sublimate  in  the 

glass  tube. 

Action  on  the  Economy.— Although  the  medicinal  compounds  of 
bismuth  are  probably  poisonous,  if  taken  in  sufficient  quantity,  the 
ill  effects  ascribed  to  them  are  in  most,  if  not  all  cases,  referable  to 
contamination  with  arsenic.  Symptoms  of  arsenical  poisoning  have 
been  frequently  observed  when  the  subnitrate  has  been  taken  inter- 
nally, and  also  when  it  has  been  used  as  a  cosmetic.  Bismuth  sub- 
nitrate  is  frequently  administered  by  physicians  in  cases  of  arsenical 
poisoning,  not  recognized  as  such  during  life. 

When  preparations  of  bismuth  are  administered,  the  alvine  dis- 
charges contain  bismuth  sulfid,  as  a  dark  brown  powder. 


VI.     TIN   GROUP. 

TITANIUM — ZIRCONIUM — TIN . 

Ti  and  Sn  are  bivalent  in  one  series  of  compounds,  SnCl2,  and 
quadrivalent  in  another,  SnCU.  Zr,  so  far  as  known,  is  always 
quadrivalent.  Each  of  these  elements  forms  an  acid  (or  salts  corre- 
sponding to  one)  of  the  composition  of  H^MOs,  and  a  series  of  oxy- 
salts  of  the  composition  of  Miv(NO3)4. 

TITANIUM. 

Symbol=Yi— Atomic  weight=4:S—8p.  gr.=5.3. 

Occurs  in  clays  and  iron  ores,  and  as  TiO2  in  several  minerals. 
Titanic  anhydrid,  TiO2,  is  a  white,  insoluble,  infusible  powder,  used 
in  the  manufacture  of  artificial  teeth;  dissolves  in  fused  KHO,  as 
potassium  titanate.  Titanium  combines  readily  with  N,  which  it 
absorbs  from  air  when  heated.  When  NHs  is  passed  over  red-hot 
TiO2,  it  is  decomposed  with  formation  of  the  violet  nitrid,  TiN2. 
Another  compound  of  Ti  and  N  forms  hard,  copper- colored,  cubical 
crystals. 

ZIRCONIUM. 

Symbol=Zr — Atomic  weight=89 — Sp.  grr.— 4.15. 

Occurs  in  zircon  and  hyacinth.  Its  oxid,  zirconia,  Zi<>2,  is  a 
white  powder,  insoluble  in  KHO.  Being  infusible,  and  not  altered 
by  exposure  to  air,  it  is  used  in  pencils  to  replace  lime  in  the  calcium 
light. 


TIN  165 

TIN. 

=  S-n.  (Stannum) —Atomic  weight  =  II8.5  (0  =  16:118.5; 
H=l:117.55)—  Molecular  weight— 235A  (l)—Sp.  0r.=7.285-7.293— 

Fuses  at  228°  (442.4°  F.). 

Occurrence. — As  tinstone  (SnO2)  or  cassiterite,  and  in  stream 
tin. 

Preparation. — The  commercial  metal  is  prepared  by  roasting  the 
ore,  extracting  with  EbO,  reducing  the  residue  by  heating  with  char- 
coal, and  refining. 

Pure  tin  is  obtained  by  dissolving  the  metal  in  HC1;  filtering; 
evaporating;  dissolving  the  residue  in  H2O:  decomposing  with  am- 
monium carbonate;  and  reducing  the  oxid  with  charcoal. 

Properties. — A  soft,  malleable,  bluish  white  metal;  but  slightly 
tenacious;  emits  a  peculiar  sound,  the  tin-cry,  when  bent.  A  good 
conductor  of  heat  and  electricity.  Air  affects  it  but  little,  except 
when  it  is  heated;  more  rapidly  if  Sn  be  alloyed  with  Pb.  It  oxidizes 
slowly  in  EbO;  more  rapidly  in  the  presence  of  sodium  chlorid.  Its 
presence  with  Pb  accelerates  the  action  of  EbO  upon  the  latter.  It 
dissolves  in  HC1  as  SnCb.  In  presence  of  a  small  quantity  of  EbO, 
HNO3  converts  it  into  metastannic  acid.  Alkaline  solutions  dissolve 
it  as  metastannates.  It  combines  directly  with  Cl,  Br,  I,  S,  P  and  As. 

Tin  plates  are  thin  sheets  of  Fe,  coated  with  Sn.  Tin  foil  con- 
sists of  thin  Iamina3  of  Sn,  frequently  alloyed  with  Pb.  Copper  and 
iron  vessels  are  tinned  after  brightening,  by  contact  with  molten  Sn. 
Pewter,  bronze,  bell  metal,  gun  metal,  britannia  metal,  speculum 
metal,  type  metal,  solder,  and  fusible  metal,  contain  Sn. 

Oxids.—  Stannous  Oxid— Protoxid  —  SnO  —134.5  —  obtained  by 
heating  the  hydroxid  or  oxalate  without  contact  of  air.  It  is  a  white, 
amorphous  powder,  soluble  in  acids,  and  in  hot,  concentrated  solution 
of  potash.  It  absorbs  O  readily. 

Stannic  Oxid — Binoxid  of  tin — SnO2 — 150.5 — occurs  native  as 
tinstone  or  cassiterite,  and  is  formed  when  Sn  or  SnO  is  heated  in  air. 
It  is  used  as  a  polishing  material,  under  the  name  of  putty  powder. 

Hydrates.  —  Stannous  Hydroxid  —  SnH2O2 — 152.5  —  is  a  white 
precipitate,  formed  by  alkaline  hydroxids  and  carbonates  in  solutions 
of  SnCl2. 

Stannic  Acid — H2SnO3 — 168.5 — is  formed  by  the  action  of  alka- 
line hydroxids  on  solutions  of  SnCU.  It  dissolves  in  solutions  of  the 
alkaline  hydroxids,  forming  stannates. 

Metastannic  Acid— H2Sn5On— 770.5— is  a  white,  insoluble  pow- 
der, formed  by  acting  on  Sn  with  EENOs. 

Chlorids.  —  Stannous  Chlorid  —  Protochlorid  —  Tin  crystals— 
SnCl2+2Aq— 189.4+36  — is  obtained  by  dissolving  Sn  in  HC1.  It 


166  MANUAL    OF    CHEMISTRY 

crystallizes  in  colorless  prisms;  soluble  in  a  small  quantity  of  H2O; 
decomposed  by  a  large  quantity,  unless  in  the  presence  of  free^HCl, 
with  formation  of  an  oxychlorid.  Loses  its  Aq  at  100  (212 
In  air  it  is  transformed  into  stannic  chlorid  and  oxychlorid.  Oxidiz- 
ing and  chlorinating  agents  convert  it  into  SnCU.  It  is  a  strong 
reducing  agent. 

Stannic  Chlorid — Bichlorid — Liquid  of  Libavius — SnCU — 260.3— 
is  formed  by  acting  on  Sn  or  SnCl2  with  Cl,  or  by  heating  Sn  in 
aqua  regia.  It  is  a  fuming,  yellowish  liquid;  sp.  gr.  2.28;  boils  at 

120°  (248°  P.). 

Analytical  Characters.— STANNOUS.— (1)  Potash  or  soda  :  white 
ppt.;  soluble  in  excess;  the  solution  deposits  Sn  when  boiled. 
(2)  Ammonium  hydroxid:  white  ppt;  insoluble  in  excess;  turns 
olive -brown  when  the  liquid  is  boiled.  (3)  Hydrogen  sulfld:  dark 
brown  ppt.;  soluble  in  KHO,  alkaline  sulfids,  and  hot  H2O.  (4) 
Mercuric  chlorid:  white  ppt.,  turning  gray  and  black.  (5)  Auric 
chlorid:  purple  or  brown  ppt.,  in  presence  of  small  quantities  of 
HXO3.  (6)  Zinc:  deposit  of  Sn. 

STANNIC. — (1)  Potash  or  ammonia:  white  ppt.;  soluble  in  ex- 
cess. (2)  Hydrogen  sulfid:  yellow  ppt.;  soluble  in  alkalies,  alkaline 
sulfids,  and  hot  HC1.  (3)  Sodium  hyposulfite:  yellow  ppt.,  when 
heated. 

VII.     PLATINUM   GROUP. 

PALLADIUM.      PLATINUM. 


VIII.     RHODIUM  GROUP. 

RHODIUM.      RUTHENIUM.       IRIDIUM 

The  elements  of  these  two  groups,  together  with  osmium,  are 
usually  classed  as  "metals  of  the  platinum  ores."  They  all  form 
hydrates  (or  salts  representing  them)  having  acid  properties.  Os- 
mium has  been  removed,  because  the  relations  existing  between  its 
compounds,  and  those  of  molybdenum  and  tungsten,  are  much  closer 
than  those  which  they  exhibit  to  the  compounds  of  these  groups. 
The  separation  of  the  remaining  platinum  metals  into  two  groups  is 
based  upon  resemblances  in  the  composition  of  their  compounds,  as 
shown  in  the  following  table. 

CHLORIDS. 

PdCl2 PtCl2  RhCl2 RuCl2 ? 

IMHi PtCl4  - RuCl4       .        .    .  IrCl4 

-......-  Rh2Cl6 Ru2Cl6        .    .  v.  Ir2Cla 


PLATINUM  167 

OXIDS. 

PdO PtO  RhO RuO IrO 

- -  Rh2O3 Ru2O3 Ir2O3 

PdO2 PtO2  RhO2 RuO2 IrO2 

- -  RhO3 RuO.»       ....  IrO3 

RuO4  .    .    .  — 


PLATINUM. 

Symlol=Pt— Atomic  weight=194:.S  (0=16:194.8;  H=l:193.25) 
— Molecular  weight= 390  (1)—8p.  gr.  =21. 1-21. 5. 

Occurrence. — Free  and  alloyed  with  Os,  Ir,  Pd,  Rh,  Ru,  Fe,  Pb, 
Au,  Ag,  and  Cu. 

Properties. — The  compact  metal  has  a  silvery  luster;  softens  at 
a  white  heat;  may  be  welded;  fuses  with  difficulty;  highly  malleable, 
ductile  and  tenacious.  Spongy  platinum  is  a  grayish,  porous  mass, 
formed  by  heating  the  double  chlorid  of  Pt  and  NH4.  Platinum 
black  is  a  black  powder,  formed  by  dissolving  PtCl2  in  solution  of 
potash,  and  heating  with  alcohol.  Both  platinum  black  and  platinum 
sponge  are  capable  of  condensing  large  quantities  of  gas,  and  act  as 
indirect  oxidants. 

Platinum  is  not  oxidized  by  air  or  O;  it  combines  directly  with  Cl, 
P,  As,  Si,  S,  and  C;  is  not  attacked  by  acids,  except  aqua  regia,  in 
which  it  dissolves  as  PtCU.  It  forms  fusible  alloys  when  heated  with 
metals  or  reducible  metallic  oxids.  It  is  attacked  by  mixtures  liber- 
ating 01,  and  by  contact  with  heated  phosphates,  silicates,  hydroxids, 
nitrates,  or  carbonates  of  the  alkaline  metals. 

Platinic  chlorid — Tetrachlorid  or  perchlorid  of  platinum — PtCU 
—336.6 — is  obtained  by  dissolving  Pt  in  aqua  regia,  and  evaporating. 
It  crystallizes  in  very  soluble,  deliquescent,  yellow  needles.  Its  solu- 
tion is  used  as  a  test  for  comDOunds  of  NELi  and  K. 


168  MANUAL    OF    CHEMISTRY 


CLASS  IV.— BASYLOUS  ELEMENTS. 

Elements  whose   Oxids   unite  with  Water  to  form  Bases;   never  to  form  Acids. 

Which   form  Oxysalts. 

I.     SODIUM   GROUP. 

Alkali   Metals. 
LITHIUM — SODIUM — POT  ASSIUM— RUBIDIUM — CESIUM — SILVER . 

Each  of  the  elements  of  this  group  forms  a  single  chlorid,  M'Cl, 
and  one  or  more  oxids,  the  most  stable  of  which  has  the  composition 
M^O.  They  are,  therefore,  univalent.  Their  hydroxids,  M'HO,  are 
more  or  less  alkaline  and  have  markedly  basic  characters.  Silver 
resembles  the  other  members  of  the  group  in  chemical  properties, 
although  it  does  not  in  physical  characters. 

The  name  "alkali,"  first  applied  to  "potash"  from  wood  ashes 
(p.  178)  is  now  used  to  designate  substances  which  are  strongly  basic, 
are  alkaline  in  reaction,  and  saponify  fats.  The  caustic  alkalies  are 
the  hydroxids  of  K  and  Na,  the  carbonated  alkalies  are  their  car- 
bonates. Volatile  alkali  is  ammonium  hydroxid  or  carbonate. 

LITHIUM. 

Symbol=Li— Atomic  weight=7  (0=16:7.03;  H— 1:6.97)—  Mole- 
cular weight=U  (1)—Sp.  gr.=0.5S9— Fuses  at  180°  (356°  F.)—  Dis- 
covered by  Arfvedson  in  1817 — Name  from  Xi^aos=stony. 

Occurrence. — Widely  distributed  in  small  quantity;  in  many  min- 
erals and  mineral  waters;  in  the  ash  of  tobacco  and  other  plants;  in 
the  milk  and  blood. 

Properties. — A  silver- white,  ductile,  volatile  metal;  the  lightest 
of  the  solid  elements;  burns  in  air  with  a  crimson  flame;  decomposes 
H2O  at  ordinary  temperatures,  without  igniting. 

Lithium  Oxid — Li2O — 30 — is  a  white  solid,  formed  by  burning 
Li  in  dry  O.  It  dissolves  slowly  in  H2O  to  form  lithium  hydroxid— 
LiHO. 

Lithium  Chlorid — LiCl — 43.5 — crystallizes  in  deliquescent,  reg- 
ular octahedra;  very  soluble  in  H2O  and  in  alcohol. 

Lithium  Bromid  —  Lithii  bromidum — (U.  S.) — LiBr  —  87  —  is 
formed  by  decomposing  lithium  sulfate  with  potassium  bromid;  or  by 
saturating  a  solution  of  HBr  with  lithium  carbonate.  It  crystallizes 
in  very  deliquescent,  soluble  needles. 

Lithium  Carbonate— Lithii  carbonas  (U.  S.;  Br.)— Li2CO3— 74— 


SODIUM  169 

is  a  white,   sparingly  soluble,   alkaline,  amorphous   powder.     With 
uric  acid  it  forms  lithium  urate  (q.  v.). 

Analytical  Characters. — (1)  Ammonium  carbonate:  white  ppt.  in 
concentrated  solutions;  not  in  dilute  solutions,  or  in  presence  of 
ammoniacal  salts.  (2)  Sodium  phosphate:  white  ppt.  in  neutral  or 
alkaline  solution;  soluble  in  acids  and  in  solutions  of  ammoniacal 
salts.  (3)  It  colors  the  Bunsen  flame  red;  and  exhibits  a  spectrum 
of  two  lines— A=6705  and  6102  (Fig.  14,  No.  4,  p.  22). 


SODIUM. 

Symbol=Nsi  (Natrium)— Atomic  weight=23  (0=16:23.05; 
H=rl:22.87)—  Molecular  weight=46  (!)—  8p.  gr. =0.972— Fuses  at 
95.6°  (204.1°  F.)— Boils  at  742°  (1368°  F.)— Discovered  ly  Davy, 
1807. 

Occurrence. — As  chlorid,  very  abundantly  and  widely  distrib- 
uted; also  as  carbonate,  nitrate,  sulfate,  borate,  etc. 

Preparation. — By  heating  a  mixture  of  dry  sodium  carbonate, 
chalk,  and  charcoal  to  whiteness  in  iron  retorts,  connected  with  suit- 
able condensers,  in  which  the  distilled  metal  collects,  under  a  layer  of 
coal  naphtha.  It  is  now  manufactured  by  the  electrolysis  of  fused 
NaHO. 

Properties. — A  silver-white  metal,  rapidly  tarnished,  and  coated 
with  a  yellow  film  in  air.  Waxy  at  ordinary  temperatures;  volatile 
at  a  white  heat,  forming  a  colorless  vapor,  which  burns  in  air  with  a 
yellow  flame. 

In  air  it  is  gradually  oxidized  from  the  surface,  but  may  be  kept 
in  closed  vessels,  without  the  protection  of  a  layer  of  naphtha.  It 
decomposes  H2O,  sometimes  explosively.  Burns  with  a  yellow  flame. 
Combines  directly  with  Cl,  Br,  I,  S,  P,  As,  Pb,  and  Sn. 

Oxids. — Two  oxids  are  known:  Sodium  monoxid — Na2O  —  a 
grayish  white  mass;  formed  when  Na  is  burnt  in  dry  air,  or  by  the 
action  of  Na  on  NaHO.  Sodium  dioxid — Na2O2 — a  white  solid, 
formed  when  Na  is  heated  in  dry  air  to  200°  (392°  F.).  Sodium 
dioxid,  or  peroxid,  is  now  manufactured  by  oxidizing  the  fused  metal 
in  dry  air  or  oxygen,  and  is  used  as  a  bleaching  and  oxidizing  agent. 
It  is  a  yellowish  white,  amorphous,  very  hygroscopic  powder.  If  the 
temperature  be  kept  low  it  dissolves  in  dilute  acids,  forming  a  strong 
solution  of  hydrogen  peroxid:  Na202+2HCl— 2NaCl+H2O2.  With 
water  it  produces  a  great  elevation  of  temperature  and  liberates 
nascent  oxygen:  2Na2O2+2H2O  =  4NaHO+O2.  With  magnesium 
sulfate  it  forms  magnesium  peroxid,  a  non-alkaline  oxydant:  Na2O2+ 
MgSO4=Na2SO4+MgO2. 


170  MANUAL    OP    CHEMISTRY 

Sodium  Hydroxid — Sodium  hydrate — Caustic  Soda— Soda  (U.S.) 
—Soda  caustica  (Br.)—  NaHO— 40—  is  formed:  (1)  When  H2O  is 
decomposed  by  Na;  (2)  by  decomposing  sodic  carbonate  by  calcium 
hydroxid:  Na2C03+CaH2O2=CO3Ca-i-2NaHO  (soda  by  lime) ;  (3)  in 
the  same  manner  as  in  (2),  using  barium  hydroxid  in  place  of  lime 
(soda  by  baryta).  It  frequently  contains  considerable  quantities  of 
As.  (4)  Caustic  soda  is  now  largely  manufactured  by  electrolytic 
decomposition  of  NaCl.  The  Castner  process  is  the  one  usually 
adopted.  In  it,  by  a  rocking  arrangement,  mercury,  as  the  cathode, 
first  takes  up  the  liberated  sodium,  and  is  then  brought  in  contact 
with  a  suitable  quantity  of  water.  The  reactions  are:  2NaCl=Na2+ 
C12,  and  Na2+2H2O=2NaHO+H2.  (See  Chlorin.) 

It  is  an  opaque,  white,  fibrous,  brittle  solid;  fusible  below  red- 
ness; sp.  gr.  2.00;  very  soluble  in  H2O,  forming  strongly  alkaline 
and  caustic  solutions  (soda  lye  and  liq.  sodae).  When  exposed  to 
air,  solid  or  in  solution,  it  absorbs  H2O  and  CO2,  and  is  converted 
into  carbonate.  Its  solutions  attack  glass. 

Sodium  Chlorid — Common  salt  —  Sea  salt — Table  salt — Sodii 
chloridum  (U.  S.;  Br.) — NaCl — 58.5 — occurs  very  abundantly  in 
nature,  deposited  in  the  solid  form  as  rock  salt;  in  solution  in  all 
natural  waters,  especially  in  sea  and  mineral  spring  waters;  in  sus- 
pension in  the  atmosphere;  and  as  a  constituent  of  almost  all  animal 
and  vegetable  tissues  and  fluids.  It  is  formed  in  an  infinite  variety 
of  chemical  reactions.  It  is  obtained  from  rock  salt,  or  from  the 
waters  of  the  sea,  or  of  saline  springs;  and  is  the  source  from  which 
all  the  Na  compounds  are  usually  obtained,  directly  or  indirectly. 

It  crystallizes  in  anhydrous,  white  cubes,  or  octahedra;  sp.  gr. 
2.078;  fuses  at  a  red  heat,  and  crystallizes  on  cooling;  sensibly  vola- 
tile at  a  white  heat;  quite  soluble  in  H2O,  the  solubility  varying  but 
slightly  with  the  variations  of  temperature.  Dilute  solutions  yield 
almost  pure  ice  on  freezing.  It  is  precipitated  from  concentrated 
solutions  by  HC1.  It  is  insoluble  in  absolute  alcohol;  sparingly  sol- 
uble in  dilute  spirit.  It  is  decomposed  by  H2SO4  with  formation  of 
HC1  and  sodium  sulfate:  2NaCl+H2SO4=2HCl+Na2S04. 

Sodium  Bromid — Sodii  bromidum  (U.  S.) — NaBr — 103  — is 
formed  by  dissolving  Br  in  solution  of  NaHO  to  saturation;  evapo- 
rating; calcining  at  dull  redness;  redissolving,  filtering,  and  crystal- 
lizing. It  crystallizes  in  anhydrous  cubes;  quite  soluble  in  H2O, 
soluble  in  alcohol. 

Sodium  lodid— Sodii  iodidum  (U.  S.)— Nal— 150— is  prepared 
by  heating  together  H2O,  Fe,  and  I  in  fine  powder;  filtering;  adding 
an  equivalent  quantity  of  sodium  sulfate,  and  some  slacked  lime, 
boiling,  decanting  and  evaporating.  Crystallizes  in  anhydrous  cubes; 
very  soluble  in  H2O;  soluble  in  alcohol. 


SODIUM  171 

Sodium  Nitrate— Cubic  or  Chili  saltpeter— Sodii  nitras  (U.  S.) ; 
Sodae  nitras  (Br.) — NaNO3 — 85 — occurs  in  natural  deposits  in  Chili 
and  Peru.  It  crystallizes  in  anhydrous,  deliquescent  rhombohedra ; 
cooling  and  somewhat  bitter  in  taste;  fuses  at  310°  (590°  F.);  very 
soluble  in  EbO.  Heated  with  EbSO^  it  is  decomposed,  yielding 
HNO3  and  hydrosodic  sulfate  :  H2S04-f  NaNO3=HNaSO4+HNO3. 
This  reaction  is  that  used  for  obtaining  HN03. 

Sulfates. — Monosodic  Sulfate — Hydrosodic  sulfate — Acid  sodium 
sulfate — Bisulfate — HNaSO* — 120 — crystallizes  in  long,  four- sided 
prisms;  is  unstable  and  decomposed  by  air,  H2O  or  alcohol,  into 
EbSCU  and  Na2SO4.  Heated  to  dull  redness  it  is  converted  into  so- 
dium pyrosulfate,  Na2S2O7,  corresponding  to  Nordhausen  sulfuric 
acid. 

Disodic  Sulfate — Sodic  sulfate — Neutral  sodium  sulfate — Glauber's 
salt— Sodii  sulfas  (U.  S.);  sodse  sulfas  (Br.)— Na2SO4+wAq— 142 
-\-n  18 — occurs  in  nature  in  solid  deposits,  and  in  solution  in  natural 
waters.  It  is  obtained  as  a  secondary  product  in  the  manufacture  of 
HC1,  by  the  action  of  H2SO4  on  NaCl,  the  decomposition  occurring 
according  to  the  equation:  2NaCl+H2SO4=Na2SO4+2 HC1,  if  the 
temperature  be  raised  sufficiently.  At  lower  temperatures,  the  rnono- 
sodic  salt  is  produced,  with  only  half  the  yield  of  HC1:  NaCl+ 
HaSO4=NaHSOH-HCl. 

It  crystallizes  with  7  Aq,  from  saturated  or  supersaturated  solu- 
tions at  5°  (41°  F.) ;  or,  more  usually,  with  10  Aq.  As  usually  met 
with  it  is  in  large,  colorless,  oblique,  rhombic  prisms  with  10  Aq; 
which  effloresce  in  air,  and  gradually  lose  all  their  Aq.  It  fuses  at 
33°  (91.4°  F.)  in  its  Aq,  which  it  gradually  loses.  If  fused  at  33° 
(91.4°  F.),  and  allowed  to  cool,  it  remains  liquid  in  supersaturated 
solution,  from  which  it  is  deposited,  the  entire  mass  becoming  solid, 
on  contact  with  a  small  particle  of  solid  matter.  It  dissolves  in  HC1 
with  considerable  diminution  of  temperature. 

Sodium  Sulfite— Sodii  sulfis  (U.  S.)—  Na2SO3  +  7  Aq  — 126+ 
126 — is  formed  by  passing  862  over  crystallized  Na2CO3.  It  crystal- 
lizes in  efflorescent,  oblique  prisms;  quite  soluble  in  H2O,  forming  an 
alkaline  solution.  It  acts  as  a  reducing  agent. 

Sodium  Thiosulfate — Sodium  hyposulfite — Sodii  hyposulfis  (U. 
S.)— Na2S2O3+5  Aq— 158+90— is  obtained  by  dissolving  S  in  hot 
concentrated  solution  of  Na2SO3,  and  crystallizing. 

It  forms  large,  colorless,  efflorescent  prisms;  fuses  at  45°  (113° 
F.);  very  soluble  in  H2O,  insoluble  in  alcohol.  Its  solutions  pre- 
cipitate alumina  from  solutions  of  Al  salts,  without  precipitating  Fe 
or  Mn;  they  dissolve  many  compounds  insoluble  in  H2O;  cuprous 
hydroxid,  iodids  of  Pb,  Ag  and  Hg,  sulfids  of  Ca  and  Pb.  It  acts  as 
a  disinfectant  and  antiseptic.  H2SO4  decomposes  Na2S2O3  according 


17'J  MANUAL    OP    CHEMISTRY 

to  the  equation :  N«*Oj+H^O4=^«^4+SOi+S+H«0;  and  most 
other  acids  behave  similarly.  Oxalic,  and  a  few  other  acids,  decom- 
pose the  thiosulfate  with  formation  of  H2S  as  well  as  SO2  and  S. 

Silicates. — Quite  a  number  of  silicates  of  Na  are  known.  If  silica 
and  Na2CO3  be  fused  together,  the  residue  extracted  with  H2O,  and 
the  solution  evaporated,  a  transparent,  glass -like  mass,  soluble  in 
warm  water,  remains;  this  is  soluble  glass  or  water  glass.  Exposed 
to  air  in  contact  with  stone,  it  becomes  insoluble,  and  forms  an  im- 
permeable coating. 

Phosphates. —  Trisodic    Phosphate — Basic  sodium  phosphate  — 
Na3PO4+12  Aq— 164+216— is  obtained  by  adding  NaHO  to  disodic 
phosphate  solution,   and   crystallizing.     It  forms  six-sided  prisms; 
quite  soluble  in  H2O.     Its  solution  is  alkaline,  and,  on  exposure  to 
air,  absorbs  CO2,  with  formation  of  HNa2PC>4  and  Na2CO3. 

Disodic  Phosphate — Hydro -disodic  phosphate — Neutral  sodium 
phosphate — Phosphate  of  soda — Sodii  phosphas  (U.  S.);  sodae  phos- 
phas  (Br.) — HNa2PO4+12  Aq — 142+216 — is  obtained  by  converting 
tricalcic  phosphate  into  monocalcic  phosphate,  and  decomposing  that 
salt  with  sodium  carbonate:  Ca(P04H2)2+2Na2CO3=CaCO3+H2O+ 
CO2+2HNa2PO4. 

Below  30°  (86°  F.)  it  crystallizes  in  oblique  rhombic  prisms,  with 
12  Aq;  at  33°  (91.4°  F.)  it  crystallizes  with  7  Aq.  The  salt  with 
12  Aq  effloresces  in  air,  and  parts  with  5  Aq;  and  is  very  soluble  in 
H2O.  The  salt  with  7  Aq  is  not  efflorescent,  and  less  soluble  in  H2O. 
Its  solutions  are  faintly  alkaline. 

Monosodic  Phosphate  —  Acid  sodium  phosphate  —  H2NaPO4+ 
Aq — 120+18 — crystallizes  in  rhombic  prisms;  forming  acid  solutions. 
At  100°  (212°  F.)  it  loses  Aq;  at  200°  (392°  F.)  it  is  converted  into 
acid  pyrophosphate,  Na2H2P2O7;  and  at  204°  (399.2°  F.)  into  the 
metaphosphate,  NaPO3. 

Sodium  Arsenites. — The  disodic  arsenite,  Na2HAsO3,  is  obtained 
as  a  viscous  mass  by  fusing  together  1  molecule  of  As2O3  and  2  mole- 
cules of  Na2C03  without  contact  of  air.  The  monosodic  arsenite, 
NaH2AsO3,  is  formed  when  an  aqueous  solution  of  Na2CO3  is  boiled 
with  As2O3.  By  prolonged  boiling  this  is  converted  into  the  pyro- 
arsenite,  Na2H2As2O5,  and  this  into  the  metarsenite,  NaAsO2,  by 
progressive  loss  of  water.  Sodium  arsenites  exist  in  embalming 
liquids  and  are  used  in  dyeing. 

Sodium  Arsenates. — The  three  arsenates,  NaH2AsO4,  Na2HAsO4 
and  Na3AsO4  corresponding  to  the  phosphates,  are  known,  and  are 
used  in  dyeing  processes, 

Disodic  Tetraborate  —  Sodium  pyroborate — Borate  of  sodium  — 
Borax—  Tincal—  Sodii  boras  (U.S.);  Borax  (Br.)—Na2B4O7+ 10  Aq 
—202+180 — is  prepared  by  boiling  boric  acid  with  Na2CO3  and  crys- 


SODIUM  173 

tallizing.  It  crystallizes  in  hexagonal  prisms  with  10  Aq;  permanent 
in  moist  air,  but  efflorescent  in  dry  air;  or  in  regular  octahedra  with 
5  Aq,  permanent  in  dry  air.  Either  form,  when  heated,  fuses  in  its 
Aq,  swells  considerably;  at  a  red  heat  becomes  anhydrous;  and,  on 
cooling,  leaves  a  transparent,  glass -like  mass.  When  fused  it  is 
capable  of  dissolving  many  metallic  oxids,  forming  variously  colored 
masses,  hence  its  use  as  a  flux  and  in  blow -pipe  analysis. 

Sodium  Hypochlorite — NaCIO — 74.5 — only  known  in  solution — 
Liq.  sodas  chloratse  (U.  S.;  Br.)  or  Labarraque's  solution — ob- 
tained by  decomposing  a  solution  of  chlorid  of  lime  by  Na2COs.  It 
it  a  valuable  source  of  Cl,  and  is  used  as  a  bleaching  and  disinfecting 
agent. 

Sodium  Chlorate  — Sodii  chloras  (U.  S.)— NaClO3  — 106.5  —  is 
manufactured  industrially  by  treating  milk  of  lime  with  Cl.  The 
solution  of  calcium  chlorid  and  chlorate  so  obtained  is  treated  with 
Na2S04,  after  removal  of  part  of  the  CaCb  by  concentration  and 
cooling  to  12°  (53.6°  F.).  The  NaClOa  and  Nad  formed  are  sepa- 
rated by  taking  advantage  of  the  greater  solubility  of  the  former. 
NaClO3  is  soluble  in  its  own  weight  of  H2O  at  20°  (68°  F.). 

Sodium  Manganate— Na2MnO4+ 10  Aq  — 164+180 — faintly  col- 
ored crystals,  forming  a  green  solution  with  HsO — Condy's  green 
disinfectant. 

Sodium  Permanganate — Na2Mn2Os — 282 — prepared  in  the  same 
way  as  the  K  salt  (q.  v.),  which  it  resembles  in  its  properties.  It 
enters  into  the  composition  of  Condy's  fluid,  and  of  "chlorozone," 
which  contains  Na2Mn2Og  and  NaCIO. 

Sodium  Acetate — Sodii  acetas  (U.  S.);  Sodae  acetas  (Br.)  — 
NaC2H302+3  Aq  —  82+54 — crystallizes  in  large,  colorless  prisms; 
acid  and  bitter  in  taste;  quite  soluble  in  H2O,  soluble  in  alcohol; 
loses  its  Aq  in  dry  air,  and  absorbs  it  again  from  moist  air.  Heated 
with  soda  lime,  it  yields  marsh  gas.  The  anhydrous  salt,  heated  with 
H2S04,  yields  glacial  acetic  acid. 

Carbonates. — Three  are  known:  Na2C(>3,   HNaCOs,   and   JEbNa*- 

(C03)3. 

Disodic  Carbonate — Neutral  Carbonate — Soda — Sal  soda — Wash- 
ing Soda — Soda  crystals — Sodii  carbonas  (U.  S.);  Sodae  carbonas 
(Br.)— Na2CO3+ 10  Aq— 106+180— industrially  the  most  important 
of  the  Na  compounds,  is  manufactured  by  Leblanc's  or  Solvay's  pro- 
cesses; or  from  cryolite,  a  native  fluorid  of  Na  and  Al. 

Leblanc's  process,  in  its  present  form,  consists  of  three  distinct 
processes:  (1)  The  conversion  of  NaCl  into  the  sulfate,  by  decom- 
position by  H2SO4.  (2)  The  conversion  of  the  sulfate  into  carbonate, 
by  heating  a  mixture  of  the  sulfate  with  calcium  carbonate  and  char- 
coal, The  product  of  this  reaction,  known  as  black  ball  soda,  is  a 


174  MANUAL    OF    CHEMISTRY 

mixture  of  sodium  carbonate  with  charcoal  and  calcium  sulfid  and 
oxid.  (3)  The  purification  of  the  product  obtained  in  (2).  The 
ball  black  is  broken  up,  disintegrated  by  steam,  and  lixiviated.  The 
solution  on  evaporation  yields  the  soda  salt  or  soda  of  commerce. 

Of  late  years  Leblanc's  process  has  been  in  great  part  replaced 
by  Solvay's  method,  or  the  ammonia  process,  which  is  more  eco- 
nomical, and  yields  a  purer  product.  In  this  process  sodium  chlorid 
and  ammonium  bicarbonate  react  upon  each  other,  with  production  of 
the  sparingly  soluble  sodium  bicarbonate,  and  the  very  soluble  am- 
monium chlorid.  The  sodium  bicarbonate  is  then  simply  collected, 
dried,  and  heated,  when  it  is  decomposed  into  Na2CO3,  H2O,  and  CC>2. 
Sodium  carbonate  is  also  made  from  cryolite,  a  double  fluorid  of  sodium 
and  aluminium  found  in  Greenland.  This  is  heated  with  limestone 
when:  Al2Na6Fi2+6CaCO3=6CaF2+6CO2+Na6Al2O6.  The  sodium 
aluminate  is  extracted  with  water  and  the  solution  treated  with  carbon 
dioxid  (obtained  in  the  first  reaction)  when  :  Na6Al2O6+3H20+ 
3CO2=3Na2CO3+ A12  ( OH )  6 . 

The  anhydrous  carbonate,  Sodii  carbonas  exsiccatus  (U.  S.), 
Na2CO3f  is  formed,  as  a  white  powder,  by  calcining  the  crystals.  It 
fuses  at  dull  redness,  and  gives  off  a  little  CO2.  It  combines  with  and 
dissolves  in  H2O  with  elevation  of  temperature. 

The  crystalline  sodium  carbonate,  Na2CO3+10Aq,  forms  large 
rhombic  crystals,  which  effloresce  rapidly  in  dry  air ;  fuse  in  their 
Aq  at  34°  (93.2°  F.);  are  soluble  in  H2O,  most  abundantly  at  38° 
(100.4°  F.).  The  solutions  are  alkaline  in  reaction. 

Monosodic  Carbonate — Hydrosodic  carbonate — Bicarbonate  of 
soda — Acid  carbonate  of  soda — Vichy  salt — Sodii  bicarbonas  (U.  S.) 
— Sodae  bicarbonas  (Br.) — NaHCOa — 84 — exists  in  solution  in  many 
mineral  waters.  It  is  obtained  by  the  action  of  CO2  upon  the  disodic 
salt  in  the  presence  of  H2O;  or,  as  above  described,  by  the  Solvay 
method. 

It  crystallizes  in  rectangular  prisms,  anhydrous  and  permanent  in 
dry  air.  In  damp  air  it  gives  off  CO2,  and  is  converted  into  the 
sesquicarbonate,  Na4H2(COs)3.  When  heated  it  gives  off  CO2  and 
H2O,  and  leaves  the  disodic  carbonate.  Quite  soluble  in  water; 
above  70°  (158°  F.)  the  solution  gives  off  CO2.  The  solutions  are 
alkaline. 

Analytical  Characters.  —  (1)  Hydrofluosilicic  acid:  gelatinous 
ppt.,  if  not  too  dilute.  (2)  Potassium  pyroantimonate,  in  neutral 
solution,  and  in  absence  of  metals  other  than  K  and  Li:  a  white, 
flocculent  ppt.;  becoming  crystalline  on  standing.  (3)  Periodic  acid 
in  excess:  white  ppt.,  in  not  too  dilute  solutions.  (4)  Colors  the 
Bunspn  flame  yellow,  and  shows  a  brilliant  double  line  at  X=5895 
and  5889  (Fig.  14,  No.  2,  p.  22). 


POTASSIUM  175 

POTASSIUM. 

Symbol  =  K  (Kalium)— Atomic  weight  =  39  (0=16:39.15;  H== 
1:38.84)—  Molecular  weight=78  (°!)—Sp.  (/r. =0.865— Fuses  at  62.5° 
(144.5°  P.)—  Boils  at  667°  (1233°  F.)— Discovered  by  Davy,  1807— 
Names  from  pot  ash,  and  Kali=ashes  (Arabic). 

Potassium  silicates  are  widely  distributed  in  rocks  and  minerals. 
The  ash  of  plants  contain  about  10  per  cent,  of  potassium  carbonate, 
and  this  was  formerly  the  chief  source  of  the  K  compounds.  Almost 
all  of  these  are  now  derived  from  the  deposits  of  carnallite:  KC1, 
MgCl2-|-6Aq,  and  allied  minerals  at  Stassfurt  in  Germany. 

It  is  prepared  by  a  process  similar  to  that  followed  in  obtaining 
Na;  is  a  silver-white  metal;  brittle  at  0°  (32°  F.) ;  waxy  at  15°  (59° 
F.) ;  fuses  at  62.5°  (144.5°  F.) ;  distils  in  green  vapors  at  a  red  heat, 
condensing  in  cubic  crystals.  It  is  also  obtained  by  electrolysis  of 
fused  KHO. 

It  is  the  only  metal  which  oxidizes  at  low  temperatures  in  dry  air, 
in  which  it  is  rapidly  coated  with  a  white  layer  of  oxid  or  hydroxid, 
and  frequently  ignites,  burning  with  a  violet  flame.  It  must,  there- 
fore, be  kept  under  naphtha.  It  decomposes  EUO,  or  ice,  with  great 
energy,  the  heat  of  the  reaction  igniting  the  liberated  H.  It  com- 
bines with  Cl  with  incandescence,  and  also  unites  directly  with  S,  P, 
As,  Sb,  and  Sn.  Heated  in  C(>2  it  is  oxidized,  and  liberates  C. 

Oxids. — Three  are  known:  K2O;  K2O2;  and  K^CU. 

Potassium  Hydroxid — Potassium  hydrate — Potash — Potassa — 
Common  caustic — Potassa  (U.  S.) — Potassa  caustica  (Br.) — KHO 
— 56 — is  obtained  by  processes  similar  to  those  used  in  manufacturing 
NaHO.  It  is  purified  by  solution  in  alcohol,  evaporation  and  fusion 
in  a  silver  basin,  and  casting  in  silver  moulds — potash  by  alcohol ; 
it  is  then  free  from  KC1  and  K2$O4,  but  contains  small  quantities  of 
K2C03,  arid  frequently  As. 

It  is  usually  met  with  in  cylindrical  sticks,  hard,  white,  opaque, 
and  brittle.  The  KHO  by  alcohol  has  a  bluish  tinge,  and  a  smoother 
surface  than  the  common;  sp.  gr.  2.1;  fuses  at  dull  redness;  is  freely 
soluble  in  H2O,  forming  a  strongly  alkaline  and  caustic  liquid;  less 
soluble  in  alcohol.  In  air,  solid  or  in  solution,  it  absorbs  H2O  and 
CO2,  and  is  converted  into  K2COa.  Its  solutions  dissolve  Cl,  Br, 
I,  S,  and  P.  It  decomposes  the  ammoniacal  salts,  with  liberation 
of  NHs;  and  the  salts  of  many  of  the  metals,  with  formation  of 
a  K  salt,  and  a  metallic  hydroxid.  It  dissolves  the  proteins,  and, 
when  heated,  decomposes  them  with  formation  of  leucin,  tyrosin, 
etc.  It  oxidizes  the  carbohydrates  with  formation  of  potassium 
oxalate  and  carbonate.  It  decomposes  the  fats  with  formation  of 
soft  soaps. 


176  MANUAL    OF    CHEMISTRY 


Sulfids.  —  Five  are  known:  K2S,  K2S2,  K^Sa,  K2S4,  and  K2S5;  also 
a  sulf  hydrate:  KHS. 

Potassium  Monosulfid—  K2S—  110—  is  formed  by  the  action  of 
KHO  on  KHS.  Potassium  Disulfid—  K2S2—  142—  is  an  orange- 
colored  solid,  formed  by  exposing  an  alcoholic  solution  of  KHS  to  the 
air.  Potassium  Trisulfid—  K2S3—  174—  a  brownish  yellow  mass, 
obtained  by  fusing  together  K2CO3  and  S  in  the  proportion:  4K2CO3+ 
10S=SO4K2+3K2S3-|-4CO2.  Potassium  Pentasulfid—  K2S5—  238— 
is  formed,  as  a  brown  mass,  when  K2CO3  and  S  are  fused  together  in 
the  proportion:  4K2CO3+16S=4CO2+3K2S5+K2SO4.  Liver  of  Sul- 
fur— fopar  sulfuris—potassii  sulfuratum  (U.  S.;  Br.)  —  is  a  mixture 
of  K2S3  and  K2S5. 

Potassium  Sulfhydrate  —  KHS  —  72  —  is  formed  by  saturating  a 
solution  of  KHO  with  H2S. 

Potassium  Chlorid  —  Sal  digestivum  Sylvii  —  KC1—  74.5  —  exists  in 
nature,  either  pure  or  mixed  with  other  chlorids;  principally  as  car- 
nallite,  KC1,  MgCl2+6  Aq.  It  crystallizes  in  anhydrous,  permanent 
cubes,  soluble  in  H2O. 

Potassium  Bromid  —  Potassii  bromidum  (U.  S.;  Br.)  —  KBr— 
119  —  is  formed  either  by  decomposing  FeBr2  by  K2CO3,  or  by  dissolv- 
ing Br  in  solution  of  KHO.  In  the  latter  case  the  bromate  formed  is 
converted  into  KBr,  by  calcination.  It  crystallizes  in  anhydrous 
cubes  or  tables;  has  a  sharp,  salty  taste;  very  soluble  in  H2O,  spar- 
ingly so  in  alcohol.  It  is  decomposed  by  Cl  with  liberation  of  Br. 

Potassium  lodid  —  Potassii  iodidum  (U.  S.;  Br.)  —  KI  —  166  —  is 
obtained  by  saturating  KHO  solution  with  I,  evaporating,  and  calcin- 
ing the  resulting  mixture  of  iodid  and  iodate  with  charcoal.  It  fre- 
quently contains  iodate  and  carbonate.  It  crystallizes  in  cubes, 
transparent  if  pure;  permanent  in  air;  anhydrous;  soluble  in  H2O 
and  in  alcohol.  It  is  decomposed  by  Cl,  HNO3  and  HNO2,  with  liber- 
ation of  I.  It  combines  with  other  iodids  to  form  double  iodids.  Its 
solutions  dissolve  iodin  and  many  metallic  iodids. 

.Potassium  Nitrate  —  Nitre  —  Saltpeter  —  Potassii  nitras  (U.  S.); 
Potassae  nitras  (Br.)  —  KNO3  —  101  —  occurs  in  nature,  and  is  pro- 
duced artificially,  as  a  result  of  the  decomposition  of  nitrogenized 
organic  substances.  It  is  usually  obtained  by  decomposing  native 
NaNO3  by  boiling  solution  of  K2OO3  or  KC1. 

It  crystallizes  in  six-sided,  rhombic  prisms,  grooved  upon  the 
surface;  soluble  in  H2O,  with  depression  of  temperature;  more  sol- 
uble in  H2O  containing  NaCl;  very  sparingly  soluble  in  alcohol;  fuses 
at  350°  (662°  F.)  without  decomposition  ;  gives  off  O,  and  is  con- 
verted into  nitrite  below  redness  ;  more  strongly  heated,  it  is  decom- 
posed into  N,  O,  and  a  mixture  of  K  oxids.  It  is  a  valuable  oxidant 
at  high  temperatures.  Heated  with  charcoal  it  deflagrates. 


POTASSIUM  177 

Gunpowder  is  an  intimate  mixture  of  KN03  with  S  and  C,  in  such 
proportion  that  the  KNO3  yields  all  the  O  required  for  the  combustion 
of  the  S  and  C. 

Potassium  Hypochlorite — KC1O — 90.5 — is  formed  in  solution  by 
imperfect  saturation  of  a  cooled  solution  of  KHO  with  hypochlorous 
acid.  An  impure  solution  is  used  in  bleaching:  Javelle  water. 

Potassium  Chlorate — Potassii  chloras  (U.  S.) — Potassse  chloras 
(Br.) — KC1O3 — 122.5 — is  prepared:  (1)  bypassing  Cl  through  a  solu- 
tion of  KHO;  (2)  by  passing  Cl  over  a  mixture  of  milk  of  lime  and 
KC1,  heated  to  60°  (140°  F.);  (3)  by  electrolysis  of  KC1.  By  elec- 
trolytic action  the  KC1  is  split  into  its  ions:  2KC1=2K+2C1;  these, 
by  secondary  reactions  with  H2O,  produce  KC1O:  K2+2H2O— 2KHO+ 
H2,  and  2KHO+C12==2KC1O-|-H2,  and  at  the  temperature  generated, 
the  KC1O  yields  KC1O3:  2KC10+H2O=KC1O3+KC1+H2.  It  crys- 
tallizes in  transparent,  anhydrous  plates,  soluble  in  H20;  sparingly 
soluble  in  weak  alcohol. 

It  fuses  at  400°  (752°  F.).  If  further  heated,  it  is  decomposed 
into  KC1  and  perchlorate,  and  at  a  still  higher  temperature  the  per- 
chlorate  is  decomposed  into  KC1  and  O:  2KC1O3=KC1O4+KC1+O2, 
and  KC1O4=KC1-|-2O2.  It  is  a  valuable  source  of  0,  and  a  more 
active  oxidant  than  KNO3.  When  mixed  with  readily  oxidizable  sub- 
stances, C,  S,  P,  sugar,  tannin,  resins,  etc.,  the  mixtures  explode 
when  subjected  to  shock.  With  strong  H2SO4  it  gives  off  C12O4,  an 
explosive  yellow  gas.  It  is  decomposed  by  HNO3  with  formation  of 
KNO3,  KC1O4,  and  liberation  of  Cl  and  O.  Heated  with  HC1  it  gives 
off  a  mixture  of  Cl  and  C12C>4,  the  latter 'acting  as  an  energetic  oxi- 
dant in  solutions  in  which  it  is  generated. 

Sulfates.— Dipotassic  sulfate— Potassium  sulfate— Potassii  sul- 
fas  (U.  S.) — Potassae  sulfas  (Br.) — K2S(>4 — 174 — occurs  native;  in 
the  ash  of  many  plants;  and  in  solution  in  mineral  waters.  It  crys- 
tallizes in  right  rhombic  prisms;  hard;  permanent  in  air;  salt  and 
bitter  in  taste;  soluble  in  H2O. 

Monopotassic  Sulfate.  —  Hydropotassic  sulfate  —  Acid  sulfate  — 
KHSO4 — 136 — is  formed  as  a  by-product  in  the  manufacture  of 
HNO3.  When  heated  it  loses  H2O,  and  is  converted  into  the  pyro- 
sulfate,  K2S2O7,  which,  at  a  higher  temperature,  is  decomposed  into 
K2SO4  and  SO3. 

Dipotassic  Sulfite — Potassic  sulfite — Potassii  sulfis  (U.  S.)  — 
K2SO3— 158— is  formed  by  saturating  solution  of  K2CO3  with  SO2, 
and  evaporating  over  H2S(>4.  It  crystallizes  in  oblique  rhombo- 
hedra;  soluble  in  H2O.  Its  solution  absorbs  O  from  the  air,  with 
formation  of  K2S(>4. 

Potassium  Bichromate  —  Bichromate  of  potash  —  Potassii  bi- 
chromas  (U.  S.)— Potassse  bichromas  (Br.)—K2Cr2O7  — 294.8  — is 

12 


178  MANUAL    OF    CHEMISTRY 

formed  by  heating  a  mixture  of  chrome  iron  ore  with  KNOs,  or  K2CO3 
in  air;  extracting  with  H2O;  neutralizing  with  dilute  H2SO4;  and 
evaporating.  It  forms  large,  reddish -orange  colored  prismatic  crys- 
tals; soluble  in  H2O;  fuses  below  redness,  and  at  a  higher  tempera- 
ture is  decomposed  into  0,  potassium  chromate,  and  chromic  oxid. 
Heated  with  HC1,  it  gives  off  Cl. 

Potassium  Permanganate  —  Potassii  permanganas  (U.  S.); 
Potassse  permanganas  (Br.) — K2Mn2Og — 314— is  obtained  by  fusing 
a  mixture  of  manganese  dioxid,  KHO,  and  KC1O3,  and  evaporating 
the  solution  to  crystallization;  K2Mn(>4,  and  KC1  are  first  formed;  on 
boiling  with  H2O,  the  manganate  is  decomposed  into  K2Mn2O8,  KHO 
and  MnO2. 

It  crystallizes  in  dark  prisms,  almost  black,  with  greenish  reflec- 
tions, which  yield  a  red  powder  when  broken.  Soluble  in  H2O, 
communicating  to  it  a  red  color,  even  in  very  dilute  solution.  It  is  a 
most  valuable  oxidizing  agent.  With  organic  matter  its  solution  is 
turned  to  green,  by  the  formation  of  the  manganate,  or  deposits  the 
brown  sesquioxid  of  manganese,  according  to  the  nature  of  the  or- 
ganic substance.  In  some  instances  the  reaction  takes  place  best  in 
the  cold,  in  others  under  the  influence  of  heat;  in  some  better  in  acid 
solutions,  in  others  in  alkaline  solutions.  Mineral  reducing  agents 
act  more  rapidly.  Its  oxidizing  powers  render  its  solutions  valuable 
as  disinfectants. 

Potassium  Acetate — Potassii  acetas  (U.  S.);  Potassae  acetas 
(Br.) — KC2Hs02 — 110 — exists  in  the  sap  of  plants;  and  it  is  by  its 
calcination  that  the  major  part  of  the  carbonate  of  wood  ashes  is 
formed.  It  is  prepared  by  neutralizing  acetic  acid  with  K2COa  or 
KHCO3. 

It  forms  crystalline  needles,  deliquescent,  and  very  soluble  in  H2O; 
less  soluble  in  alcohol.  Its  solutions  are  faintly  alkaline. 

Carbonates.— Dipotassic  Carbonate — Potassic  Carbonate — Salt 
of  tartar — Pearl  ash— Potassii  carbonas  (U.  S.)  ;  Potassae  car- 
bonas  (Br.) — K2COa — 138 — exists  in  mineral  waters,  and  in  the  ani- 
mal economy.  It  is  prepared  industrially,  in  an  impure  form,  known 
as  potash  or  pearlash,  from  wood  ashes,  from  the  molasses  of  beet 
sugar,  and  from  the  native  Stassfurth  chlorid.  It  is  obtained  pure  by 
decomposing  the  monopotassic  salt,  purified  by  several  recrystalliza- 
tions,  by  heat;  or  by  calcining  a  potassium  salt  of  an  organic  acid. 
Thus  cream  of  tartar,  mixed  with  nitre  and  heated  to  redness,  yields  a 
black  mixture  of  C  and  K2CO.-j,  called  black  flux;  on  extracting  which 
with  H2O,  a  pure  carbonate,  known  as  salt  of  tartar,  is  dissolved. 

Anhydrous,  it  is  a  white,  granular,  deliquescent,  very  soluble  pow- 
der. At  low  temperatures  it  crystallizes  with  2Aq.  Its  solution  is 
alkaline. 


POTASSIUM  179 

Monopotassic  Carbonate — Hydropotassic  carbonate — Bicarbonate 
— Potassii  bicarbonas  (U.  S.);  Potassae  bicarbonas  (Br.) — HKCOs 
—100 — is  obtained  by  dissolving  E^COs  in  H2O,  and  saturating  the 
solution  with  C(>2.  It  crystallizes  in  oblique  rhombic  prisms,  much 
less  soluble  than  the  carbonate.  In  solution,  it  is  gradually  converted 
into  the  dipotassic  salt  when  heated,  when  brought  into  a  vacuum,  or 
when  treated  with  an  inert  gas.  The  solutions  are  alkaline  in  reaction 
and  in  taste,  but  are  not  caustic. 

The  substance  used  in  baking,  under  the  name  salaeratus,  is  this 
or  the  corresponding  Na  salt,  usually  the  latter.  Its  extensive  use  in 
some  parts  of  the  country  is  undoubtedly  in  great  measure  the  cause 
of  the  prevalence  of  dyspepsia.  When  used  alone  in  baking,  it 
"raises"  the  bread  by  decomposition  into  carbon  dioxid  and  dipo- 
tassic (or  disodic)  carbonate,  the  latter  producing  disturbances  of 
digestion  by  its  strong  alkaline  reaction. 

Monopotassic  Oxalate — Hydropotassic  oxalate — Binoxalate  of  pot- 
ash— KHC204 — 128 — forms  transparent,  soluble,  acid  needles.  It 
occurs  along  with  the  quadroxalate  HKC2O4,  H2C2O4~h2Aq,  in  salt  of 
lemon  or  salt  of  sorrel,  used  in  straw  bleaching,  and  for  the  removal 
of  ink -stains,  etc.  It  closely  resembles  Epsom  salt  in  appearance, 
and  has  been  fatally  mistaken  for  it. 

Tartrates. — Dipotassic  Tartrate — Potassic  tartrate — Soluble  tartar 
— Neutral  tartrate  of  potash — Potassii  tartras  (U.  S.) — Potassae  tar- 
tras  (Br.) — K^CiELtOe — 226 — is  prepared  by  neutralizing  the  hydropo- 
tassic  salt  with  potassium  carbonate.  It  forms  a  white,  crystalline 
powder,  very  soluble  in  EbO,  the  solution  being  dextrogyrous, 
[a]p=+28.48°j  soluble  in  alcohol.  Acids,  even  acetic,  decompose 
its  solution,  with  precipitation  of  the  monopotassic  salt. 

Monopotassic  Tartrate — Hydropotassic  tartrate — Cream  of  tartar 
—Potassii  bitartras  (U.  S.)— Potassae  bitartras  (Br.)— HKC4H4O6 
— 188. — During  the  fermentation  of  grape  juice,  as  the  proportion  of 
alcohol  increases,  crystalline  crusts  collect  in  the  cask.  These  consti- 
tute the  crude  tartar,  or  argol,  of  commerce,  which  is  composed,  in 
great  part,  of  monopotassic  tartrate,  with  some  calcium  tartrate  and 
coloring  matter.  The  crude  product  is  purified  by  repeated  crystalli- 
zation from  boiling  EbO,  decolorizing  with  animal  charcoal,  digesting 
the  purified  tartar  with  HC1  at  20°  (68°  P.),  washing  with  cold  H2O, 
and  crystallizing  from  hot  EbO. 

It  crystallizes  in  hard,  opaque  (translucent  when  pure),  rhombic 
prisms,  which  have  an  acidulous  taste,  and  are  very  sparingly  soluble 
in  EbO,  still  less  soluble  in  alcohol.  Its  solution  is  acid,  and  dis- 
solves many  metallic  oxids  with  formation  of  double  tartrates.  When 
boiled  with  antimony  trioxid,  it  forms  tartar  emetic. 

It  is  used  in  the  household,  combined  with  monosodic  carbonate, 


180 


MANUAL    OF    CHEMISTRY 


in  baking,  the  two  substances  reacting  upon  each  other  to  form 
Rochelle  salt,  with  liberation  of  carbon  dioxid. 

Baking  Powders  are  now  largely  used  as  substitutes  for  yeast  to 
"raise"  biscuits,  cakes,  etc.  Their  action  is  based  upon  the  decom- 
position of  HNaCOs  by  some  salt  having  an  acid  reaction,  or  by  a 
weak  acid.  In  addition  to  the  bicarbonate  and  flour,  or  cornstarch 
(added  to  render  the  bulk  convenient  to  handle  and  to  diminish  the 
rapidity  of  the  reaction),  they  contain  cream  of  tartar,  tartaric  acid, 
alum,  or  acid  phosphates.  Sometimes  ammonium  sesquicarbonate  is 
used,  in  whole  or  in  part,  in  place  of  sodium  carbonate. 

The  reactions  by  which  the  002  is  liberated  are : 


1.  HKC4H4O9      4- 

NaHCO3 

=       NaKC4H4O6 

Monopotassic 

Monosodic 

Sodium  potassium 

tartrate. 

carbonate. 

tartrate. 

2.  H2C4H406      4- 

2NaHC03 

=      Na2C4H406 

Tartaric  acid. 

Monosodic 

.Disodic  tartrate. 

carbonate. 

3.  A12(SO4)3,K2SO4 

Aluminium 
potassium  alum. 


6NaHC03 

Monosodic 
carbonate. 


K2S04 

Dipotassie 

sulfate. 


H20      4-      CO2 

Water.  Carbon 

dioxid. 

2H20        4-        2C02 
Water.  Carbon 

dioxid. 

4-       3Na2SO4     4- 
Disodic 
sulfate. 


+        A12H6O6  4-        6CO2 

Aluminium  Carbon 

hydroxid.  dioxid. 

4.  A12(S04)3,(NH4)2S04     4-    6NaHC03  =     (NH4)2SO4     4- 

Aluminium  Monosodic  Diammonic 

ammonium  alum.  carbonate.  sulfate. 


3Na2S04     4- 
Disodic 
sulfate. 


4-        A12H606        4- 

Aluminium 
hydroxid. 

6C02 

Carbon 
dioxid. 

5. 

A12(S04)3 
Aluminium 
sulfate. 

4-       6NaHCO3 
Monosodic 
carbonate. 

=      3Na2SO4 

Disodic 
sulfate. 

4-       A12H606       4- 
Aluminium 
hydroxid. 

6CO2 
Carbon 
dioxid. 

G. 

NaH2PO4 

Monosodic 
phosphate. 

4-       NaHC03 

Monosodic 
carbonate. 

=    Na2HP04 
Disodic 
phosphate. 

4-        H20           f 

Water. 

C02 

Carbon 
dioxid. 

Sodium  Potassium  Tartrate— Rochelle  salt — Sel  de  seignette— 
Potassii  et  sodii  tartras  (U.  S.)— Soda  tartarata  (Br.)—  NaKC4H4- 
O6+4Aq— 210+72— is  prepared  by  saturating  monopotassic  tartrate 
with  disodic  carbonate.  It  crystallizes  in  large,  transparent  prisms, 
which  effloresce  superficially  in  dry  air  and  attract  moisture  in  damp 
air.  It  fuses  at  70°-80°  (158-176°  F.),  and  loses  3Aq  at  100°  (212° 
F.) .  It  is  soluble  in  1.4  parts  of  cold  H2O. 

Potassium  Antimonyl  Tartrate — Tartarated  antimony — Tartar 
emetic — Antimonii  et  potassii  tartras  (U.  S.) — Antimonium  tar- 
taratum  (Br.)— (SbO)KC4H4O6+%Aq— 331.6— is  prepared  by  boil- 


POTASSIUM  181 

ing  a  mixture  of  3  pts.  Sb2O3  and  4  pts.  HKC4H4O6  in  H2O  for  an 
hour,  filtering,  and  allowing  to  crystallize.  When  required  pure,  it 
must  be  made  from  pure  materials. 

It  crystallizes  in  transparent,  soluble,  right  rhombic  octahedra, 
which  turn  white  in  air.  Its  solutions  are  acid  in  reaction,  have  a 
nauseating  metallic  taste,  and  are  precipitated  by  alcohol.  The  crys- 
tals contain  %  Aq,  which  they  lose  entirely  at  100°  (212°  F.),  and, 
partially,  by  exposure  to  air.  It  is  decomposed  by  the  alkalies,  alka- 
line earths,  and  alkaline  carbonates,  with  precipitation  of  Sb20a.  The 
precipitate  is  redissolved  by  excess  of  soda  or  potash,  or  by  tartaric 
acid.  HC1,  H2SO4  and  HNOs  precipitate  corresponding  antimonyl 
compounds  from  solutions  of  tartar  emetic.  It  converts  mercuric  into 
mercurous  chlorid.  It  forms  double  tartrates  with  the  tartrates  of 
the  alkaloids. 

Potassium  Cyanid — Potassii  cyanidum  (U.  S.) — KCN — 65 — is 
obtained  by  heating  a  mixture  of  potassium  ferrocyanid  and  dry 
K2CO3,  as  long  as  effervescence  continues;  decanting  and  crystal- 
lizing. 

It  is  usually  met  with  in  dull,  white,  amorphous  masses.  Odorless 
when  dry,  it  has  the  odor  of  hydrocyanic  acid  when  moist.  It  is  deli- 
quescent, and  very  soluble  in  EbO;  almost  insoluble  in  alcohol.  Its 
solution  is  acrid  and  bitter  in  taste,  with  an  after- taste  of  hydrocyanic 
acid.  It  is  very  readily  oxidized  to  the  cyanate,  a  property  which 
renders  it  valuable  as  a  reducing  agent.  Solutions  of  KCN  dissolve 
I,  AgCl,  the  cyanids  of  Ag  and  Au,  and  many  metallic  oxids. 

It  is  actively  poisonous,  and  produces  its  effects  by  decomposition 
and  liberation  of  hydrocyanic  acid  (q.  v.). 

Potassium  Ferrocyanid — Yellow  prussiate  of  potash  —  Potas- 
sii ferrocyanidum  (U.  S.);  Potassae  prussias  flava  (Br.)  — 
K4[Fe(CN)6]  +  3  Aq— 367.9+54.— This  salt,  the  source  of  the  other 
cyanogen  compounds,  is  manufactured  by  adding  nitrogenous  organic 
matter  (blood,  bones,  hoofs,  leather,  etc.)  and  iron  to  K^COa  in 
fusion;  or  by  other  processes  in  which  the  N  is  obtained  from  the 
residues  of  the  purification  of  coal  gas,  from  atmospheric  air,  or  from 
ammoniacal  compounds. 

It  forms  soft,  flexible,  lemon -yellow  crystals,  permanent  in  air  at 
ordinary  temperatures.  They  begin  to  lose  Aq  at  60°  (140°  F.),  and 
become  anhydrous  at  100°  (212°  F.).  Soluble  in  H2O;  insoluble  in 
alcohol,  which  precipitates  it  from  its  aqueous  solution.  When  cal- 
cined with  KHO  or  K^COs  potassium  cyanid  and  cyanate  are  formed, 
and  Fe  is  precipitated.  Heated  with  dilute  H2SO4,  it  yields  an  insol- 
uble white  or  blue  salt,  potassium  sulfate,  and  hydrocyanic  acid.  Its 
solutions  form,  with  those  of  many  of  the  metallic  salts,  insoluble 
ferrocyanids;  those  of  Zn,  Pb,  and  Ag  are  white,  cupric  ferrocyanid 


182  MANUAL    OF    CHEMISTRY 

is  mahogany -colored,  ferrous  ferrocyanid  is  bluish  white,  ferric  ferro- 
cyanid,  Prussian  blue,  is  dark  blue.  Blue  ink  is  a  solution  of  Prus- 
sian blue  in  a  solution  of  oxalic  acid. 

Potassium  Ferricyanid — Red  prussiate  of  potash — K6Fe2(CN)i2 
— 657.8 — is  prepared  by  acting  upon  the  ferrocyanid  with  chlorin;  or, 
better,  by  heating  the  white  residue  of  the  action  of  H2SO4  upon 
potassium  ferrocyanid,  in  the  preparation  of  hydrocyanic  acid,  with  a 
mixture  of  1  vol.  HNOs  and  20  vols.  H2O;  the  blue  product  is  di- 
gested with  EkO,  and  potassium  ferrocyanid,  the  solution  filtered  and 
evaporated.  It  forms  red,  oblique  rhombic  prisms,  almost  insoluble 
in  alcohol.  With  solutions  of  ferrous  salts  it  gives  a  dark  blue  pre- 
cipitate, Turnbull's  blue. 

Analytical  Characters. — (1)  Platinic  chlorid,  in  presence  of  HC1 : 
yellow  ppt.,  K^PtCle;  crystalline  if  slowly  formed;  sparingly  soluble 
in  EhO,  much  less  so  in  alcohol.  (2)  Tartaric  acid  in  not  too  dilute 
solution:  white  ppt.;  soluble  in  alkalies  and  in  concentrated  acids. 
(3)  Hydrofluosilicic  acid:  translucent,  gelatinous  ppt. ;  forms  slowly ; 
soluble  in  strong  alkalies.  (4)  Perchloric  acid:  white  ppt.;  spar- 
ingly soluble  in  H20;  insoluble  in  alcohol.  (5)  Phosphomolybdic 
acid:  white  ppt.;  forms  slowly.  (6)  Colors  the  Bunsen  flame  violet 
(the  color  is  only  observable  through  blue  glass  in  the  presence  of 
Na) ,  and  exhibits  a  spectrum  of  two  bright  lines :  A.  =  7860  and  4045 
(Fig.  14,  No.  3,  p.  22). 

Action  of  the  Sodium  and  Potassium  Compounds  on  the 
Economy. — The  hydroxids  of  Na  and  K,  and  in  a  less  degree  the 
carbonates,  disintegrate  animal  tissues,  dead  or  living,  with  which 
they  come  in  contact,  and,  by  virtue  of  this  action,  act  as  powerful 
caustics  upon  a  living  tissue.  Upon  the  skin,  they  produce  a  soapy 
feeling,  and  in  the  mouth  a  soapy  taste.  Like  the  acids,  they  cause 
death,  either  immediately,  by  corrosion  or  perforation  of  the  stomach; 
or,  secondarily,  after  weeks  or  months,  by  closure  of  one  or  both 
openings  of  the  stomach,  due  to  thickening,  consequent  upon  inflam- 
mation. 

The  treatment  consists  in  the  neutralization  of  the  alkali  by  an 
acid,  dilute  vinegar.  Neutral  oils  and  milk  are  of  service,  more  by 
reason  of  their  emollient  action  than  for  any  power  they  have  to 
neutralize  the  alkali,  by  the  formation  of  a  soap,  at  the  temperature 
of  the  body. 

The  other  compounds  of  Na,  if  the  acid  be  not  poisonous,  are 
without  deleterious  action,  unless  taken  in  excessive  quantity.  Com- 
mon salt  has  produced  paralysis  and  death  in  a  dose  of  half  a  pound. 
The  neutral  salts  of  K,  on  the  contrary,  are  by  no  means  without  true 
poisonous  action  when  taken  internally,  or  injected  subcutaneoosly, 
in  sufficient  quantities;  causing  dyspnoea,  convulsions,  arrest  of  the 


SILVER  183 

heart's  action,  and  death.  In  the  adult  human  subject,  death  has 
followed  the  ingestion  of  doses  of  15-30  gms.  of  the  nitrate,  in  several 
instances;  doses  of  8-60  gms.  of  the  sulfate  have  also  proved  fatal. 

Cesium — Symbol=Cs — Atomic  weight  =133;  and  Rubidium — 
Symbol=Rb — Atomic  weight=85A — are  two  rare  elements,  discovered 
in  1860  by  Kirchoff  and  Bunsen  while  examining  spectroscopically  the 
ash  of  a  spring  water.  They  exist  in  very  small  quantity  in  lepidolite. 
They  combine  with  O  and  decompose  H2O  even  more  energetically 
than  does  K,  forming  strongly  alkaline  hydroxids. 


SILVER. 

Symbol  =Ag(Argentum}  —  Atomic  weight  =  W8  (0  =  16:107.93; 
H=l :  107.07)—  Molecular  weight  =  216  (!)—  Sp.  0r.  =10.4-10.54- 
Fusesat  1,000°  (1,832°  F.). 

Although  silver  is  usually  classed  with  the  "  noble  metals,"  it 
differs  from  Au  and  Pt  widely  in  its  chemical  characters,  in  which  it 
more  closely  resembles  the  alkaline  metals. 

When  pure  Ag  is  required,  coin  silver  is  dissolved  in  HNOa  and 
the  diluted  solution  precipitated  with  HC1.  The  silver  chlorid  is 
washed,  until  the  washings  no  longer  precipitate  with  silver  nitrate; 
and  reduced,  either  (1)  by  suspending  it  in  dilute  H2S04  in  a  plati- 
num basin,  with  a  bar  of  pure  Zn,  and  washing  thoroughly,  after 
complete  reduction;  or  (2)  by  mixing  it  with  chalk  and  charcoal 
(AgCl,  100  parts;  C,  5  parts;  CaCO3,  70  parts),  and  gradually  intro- 
ducing the  mixture  into  a  red-hot  crucible. 

Silver  is  a  white  metal ;  very  malleable  and  ductile  ;  the  best 
known  conductor  of  heat  and  electricity.  It  is  not  acted  on  by  pure 
air,  but  is  blackened  in  air  containing  a  trace  of  EkS.  It  combines 
directly  with  Cl,  Br,  I,  S,  P,  and  As.  Hot  EbSCU  dissolves  it  as  sul- 
fate, and  HNO3  as  nitrate.  The  caustic  alkalies  do  not  affect  it.  It 
alloys  readily  with  many  metals;  its  alloy  with  Cu  is  harder  than  the 
pure  metal. 

Silver  seems  to  exist  in  a  number  of  allotropic  modifications,  be- 
sides that  in  which  it  is  ordinarily  met  with.  In  one  of  these  it  is 
brilliant,  metallic,  bluish  green  in  color,  and  dissolves  in  H2O,  form- 
ing a  deep  red  solution;  in  another  it  has  the  color  of  burnished  gold, 
when  dry;  and  in  still  another  it  has  also  a  bluish  green  color,  but  is 
insoluble  in  water.  Very  dilute  mineral  acids  immediately  convert 
these  modifications  into  normal  gray  silver,  without  evolution  of  any 
gas. 

Oxids.  —  Three  oxids  of  silver  are  known  :  Ag4O,  Ag2<3,  and 
Ag2O2. 


184  MANUAL    OF    CHEMISTRY 

Silver  Monoxid  —  Protoxid — Argenti  oxidum — (U.  S.  ;  Br.)— 
Ag2O — 231.8 — formed  by  precipitating  a  solution  of  silver  nitrate 
with  potash.  It  is  a  brownish  powder  ;  faintly  alkaline  and  very 
slightly  soluble  in  H2O ;  strongly  basic.  It  readily  gives  up  its 
oxygen.  On  contact  with  ammonium  hydroxid  it  forms  a  fulmi- 
nating powder. 

Silver  Chlorid — AgCl — 143.4 — formed  when  HC1  or  a  chlorid  is 
added  to  a  solution  containing  silver.  It  is  white;  turns  violet  and 
black  in  sunlight ;  volatilizes  at  260°  (500°  F.) ;  sparingly  soluble  in 
HC1;  soluble  in  solutions  of  the  alkaline  chlorids,  thiosulfates,  and 
cyanids,  and  in  ammonium  hydroxid.  It  crystallizes  in  octahedra  on 
exposure  of  its  ammoniacal  solution. 

Silver  Bromid — AgBr  —  and  lodid — Agl — are  yellowish  pre- 
cipitates, formed  by  decomposing  silver  nitrate  with  potassium  bromid 
and  iodid.  The  former  is  very  sparingly  soluble  in  ammonium  hy- 
droxid, the  latter  is  insoluble. 

Silver  Nitrate  — Argenti  Nitras  (U.  S.;  Br.)—AgNO3— 169.9 
— is  prepared  by  dissolving  Ag  in  HNOs,  evaporating,  fusing,  and 
recrystallizing.  It  crystallizes  in  anhydrous,  right  rhombic  plates; 
soluble  in  IbO.  The  solutions  are  colorless  and  neutral.  In  the 
presence  of  organic  matter  it  turns  black  in  sunlight. 

The  salt,  fused  and  cast  into  cylindrical  moulds,  constitutes  lunar 
caustic,  lapis  infernalis ;  argenti  nitras  fusa  (U.  S.).  If,  during 
fusion,  the  temperature  be  raised  too  high,  it  is  converted  into  nitrite, 
O,  and  Ag;  and  if  sufficiently  heated  leaves  pure  Ag. 

Dry  Cl  and  I  decompose  it,  with  liberation  of  anhydrous  HN'Os. 
It  absorbs  NHs,  to  form  a  white  solid,  AgNOa,  3NH3,  which  gives  up 
its  NHs  when  heated.  Its  solntion  is  decomposed  very  slowly  by  H, 
with  deposition  of  Ag. 

Silver  Cyanid— Argenti  Cyanidum— (U.  S.)— AgCN— 133.9— 
is  prepared  by  adding  KCN  or  HCN  to  a  solution  of  AgNOs.  It  is  a 
white,  tasteless  powder;  gradually  turns  brown  in  daylight;  insoluble 
in  dilute  acids;  soluble  in  ammonium  hydroxid,  and  in  solutions  of 
ammoniacal  salts,  cyanids,  or  thiosulfates.  The  strong  mineral  acids 
decompose  dt  with  liberation  of  HCN. 

Analytical  Characters. — (1)  Hydrochloric  acid:  white  flocculent 
ppt;  soluble  in  NHJIO;  insoluble  in  HNO3.  (2)  Potash  or  soda: 
brown  ppt.;  insoluble  in  excess;  soluble  in  NHiHO.  (3)  Ammonium 
hydroxid,  from  neutral  solutions:  brown  ppt.;  soluble  in  excess.  (4) 
Hydrogen  sulfid  or  ammonium  sulf hydrate:  black  ppt.;  insoluble  in 
NEUHS.  (5)  Potassium  bromid:  yellowish  white  ppt.;  insoluble  in 
acids,  if  not  in  great  excess  ;  soluble  in  NHiHO.  (6)  Potassium 
iodid;  same  as  KBr,  but  the  ppt.  is  less  soluble  in  NH4HO. 

Action  on  the  Economy. — Silver  nitrate  acts  both  locally  as  a 


AMMONIUM    COMPOUNDS  185 

corrosive,  and  systemically  as  a  true  poison.  Its  local  action  is  due 
to  its  decomposition,  by  contact  with  organic  substances,  resulting  in 
the  separation  of  elementary  Ag,  whose  deposition  causes  a  black 
stain,  and  liberation  of  free  HNOs,  which  acts  as  a  caustic.  When 
absorbed,  it  causes  nervous  symptoms,  referable  to  its  poisonous 
action.  The  blue  coloration  of  the  skin,  observed  in  those  to  whom 
it  is  administered  for  some  time,  is  due  to  the  reduction  of  the  metal, 
under  the  combined  influence  of  light  and  organic  matter;  especially 
of  the  latter,  as  the  darkening  is  observed,  although  it  is  less  intense, 
in  internal  organs. 

In  acute  poisoning  by  silver  nitrate,  sodium  chlorid  or  white  of 
egg  should  be  given  ;  and,  if  the  case  be  seen  before  the  symptoms  of 
corrosion  are  far  advanced,  emetics. 


AMMONIUM    COMPOUNDS. 

The  Ammonium  Theory. — Although  the  radical  ammonium, 
NEU,  has  probably  never  been  isolated,  its  existence  in  the  ammo- 
niacal  compounds  is  almost  universally  admitted.  The  ammonium 
hypothesis  is  based  chiefly  upon  the  following  facts:  (1)  the  close 
resemblance  of  the  ammoniacal  salts  to  those  of  K  and  Na;  (2)  when 
ammonia  gas  and  an  acid  gas  come  together,  they  unite,  without  libera- 
tion of  hydrogen,  to  form  an  ammoniacal  salt;  (3)  the  diatomic  an- 
hydrids  unite  directly  with  dry  ammonia  with  formation  of  the 
ammonium  salt  of  an  amido  acid: 

S03         +         2NH3  S03(NH2)(NH4) 

Sulfur  trioxid.  Ammonia.  Ammonium  sulfamate. 

(4)  when  solutions  of  the  ammoniacal  salts  are  subjected  to  elec- 
trolysis, a  mixture,  having  the  composition  NHa+H  is  given  off  at 
the  negative  pole;  (5)  amalgam  of  sodium,  in  contact  with  a  concen- 
trated solution  of  ammonium  chlorid,  increases  much  in  volume,  and 
is  converted  into  a  light,  soft  mass,  having  the  luster  of  mercury. 
This  ammonium  amalgam  is  decomposed  gradually,  giving  off  am- 
monia and  hydrogen  in  the  proportion  NHs+H;  (6)  if  the  gases 
NHs-j-H,  given  off  by  decomposition  of  the  amalgam,  exist  there  in 
simple  solution,  the  liberated  H  would  have  the  ordinary  properties  of 
that  element.  If,  on  the  other  hand,  they  exist  in  combination,  the 
H  would  exhibit  the  more  energetic  affinities  of  an  element  in  the 
nascent  state.  The  hydrogen  so  liberated  is  in  the  nascent  state. 

Ammonium  Hydroxid — Caustic  ammonia  —  NEUHO  —  35  —  has 
never  been  isolated,  probably  owing  to  its  tendency  to  decomposition; 
NH4HO=NH3H-H2O.  It  is  considered  as  existing  in  the  so-called 
aqueous  solutions  of  ammonia.  These  are  colorless  liquids;  of  less 


186  MANUAL    OF    CHEMISTRY 


sp.  gr.  than  IkO;  strongly  alkaline;  and  having  the  taste  and  odor 
of  ammonia,  which  gas  they  give  off  on  exposure  to  air,  and  more 
rapidly  when  heated.  They  are  neutralized  by  acids,  with  elevation 
of  temperature  and  formation  of  ammoniacal  salts.  The  Aqua  am- 
moniae(U.  S.)  and  Liq.  ammoniac  (Br.)  are  such  solutions. 

Sulfids.  —  Four  are  known:  (NEUhS,  ^£[4)282,  (NH4)2S4,  and 
(NH4)2S5;  as  well  as  a  sulfhydrate  (NH4)HS. 

Ammonium  Sulfhydrate—  NH4HS—  51—  is  formed,  in  solution, 
by  saturating  a  solution  of  NH4HO  with  H2S;  or,  anhydrous,  by 
mixing  equal  volumes  of  dry  NH3  and  dry  EbS. 

The  anhydrous  compound  is  a  colorless,  transparent,  volatile  and 
soluble  solid.  The  solution,  when  freshly  prepared,  is  colorless,  but 
soon  becomes  yellow  from  oxidation,  and  formation  of  ammonium 
disulfid  and  thiosulfate,  and  finally  deposits  sulfur. 

The  sulfids  and  hydrosulfid  of  ammonium  are  also  formed  during 
the  decomposition  of  protein  bodies,  and  exist  in  the  gases  formed  in 
burial  vaults,  sewers,  etc. 

Ammonium  Chlorid  —  Sal  ammoniac  —  Ammonii  chloridum  (U. 
S.;  Br.)  —  NH4C1  —  53.5—  is  obtained  from  the  ammoniacal  water  of 
gas  works.  It  is  a  translucid,  fibrous,  elastic  solid  ;  salty  in  taste, 
neutral  in  reaction;  volatile  without  fusion  or  decomposition;  soluble 
in  EkO.  Its  solution  is  neutral,  but  loses  NH3  and  becomes  acid 
when  boiled. 

Ammonium  chlorid  exists  in  small  quantity  in  the  gastric  juice  of 
the  sheep  and  dog;  also  in  the  perspiration,  urine,  saliva  and  tears. 

Ammonium  Bromid  —  Ammonii  bromidum  (U.  S.)  —  (NH4)Br 
—98  —  is  formed  either  by  combining  NH3  and  HBr;  by  decomposing 
ferrous  bromid  with  NH4HO;  or  by  double  decomposition  between 
KBr  and  (NH4)2SO4.  It  is  a  white,  granular  powder,  or  crystallizes 
in  large  prisms,  which  turn  yellow  on  exposure  to  air;  quite  soluble 
in  H20;  V9latile  without  decomposition. 

Ammonium  lodid  —  Ammonii  iodidum  (U.  S.)  —  NH4I  —  145  —  is 
formed  by  union  of  equal  volumes  of  NH3  and  HI;  or  by  double  de- 
composition of  KI  and  (NH4)2S04.  It  crystallizes  in  deliquescent, 
very  soluble  cubes. 

Ammonium  Nitrate  —  Ammonii  nitras  —  (U.  S.)  —  (NH4)NO3  —  80 
—  is  prepared  by  neutralizing  HNO3  with  ammonium  hydroxid  or  car- 
bonate. It  crystallizes  in  flexible,  anhydrous,  six-sided  prisms;  very 
soluble  in  H^O,  with  considerable  diminution  of  temperature;  fuses 
at  150°  (302°  F.),  and  decomposes  at  210°  (410°  F.),  with  formation 
of  nitrous  oxid:  (NH4)NO3=N2O+2H2O.  If  the  heat  be  suddenly 
applied,  or  allowed  to  surpass  250°  (482°  F.),  NH3,  NO,  and  N2O  are 
formed.  When  fused  it  is  an  active  oxidant. 

Sulfates.  —  Diammonic    Sulfate  —  Ammonic   sulfate  —  Ammonii 


AMMONIUM    COMPOUNDS  187 

sulfas  (U.  S.)— (NH4)2S04— 132— is  obtained  by  collecting  the  dis- 
tillate from  a  mixture  of  ammoniacal  gas  liquor  and  lime  in  EbSC^. 
It  forms  anhydrous,  soluble,  rhombic  crystals;  fuses  at  140° (284°  F.), 
and  is  decomposed  at  200°  (392°  F.)  into  NH3  and  H(NH4)SO4. 

Monoammonic  Sulfate — Hydroammonic  sulfate — Bisulfate  of  am- 
monia— H(NH4)SO4 — 115 — is  formed  by  the  action  of  EL2SO4  on 
(NH4)2S04.  It  crystallizes  in  right  rhombic  prisms,  soluble  in  H2O 
and  in  alcohol. 

Ammonium  Acetate — (NEU^HaCh — 77 — is  formed  by  saturating 
acetic  acid  with  NH3,  or  with  ammonium  carbonate.  It  is  a  white, 
odorless,  very  soluble  solid;  fuses  at  86°  (186.8°  F.),  and  gives  off 
NH3;  then  acetic  acid,  and  finally  acetamid.  Liq.  ammonii  acetatis 
=  Spirit  of  Mindererus  is  an  aqueous  solution  of  this  salt. 

Carbonates. — Diammonic  Carbonate — Ammonic  carbonate — Neu- 
tral ammonium  carbonate — (NH^COs+Aq — 96-fl8 — has  been  ob- 
tained as  a  white  crystalline  solid.  In  air  it  is  rapidly  decomposed 
intoNH3  and  H(NH4)C03. 

Monoammonic  Carbonate— Hydroammonic  carbonate — Acid  car- 
bonate of  ammonia — EL(NH4)CO3 — 79 — is  prepared  by  saturating  a 
solution  of  NH4HO  or  ammonium  sesquicarbonate  with  CO2.  It  crys- 
tallizes in  large,  rhombic  prisms;  quite  soluble  in  EbO.  At  60° 
(140°  F.)  it  is  decomposed  into  NH3  and  CO2. 

Ammonium  Sesquicarbonate — Sal  volatile — Preston  salts  — 
Ammonii  carbonas  (U.  S.);  Ammoniae  carbonas  (Br.) — NH4HCO3 
+NH4CO2NH2 — 157 — is  prepared  by  heating  a  mixture  of  NH4C1  or 
(NH4)  280)4  and  chalk,  and  condensing  the  product.  It  crystallizes  in 
rhombic  prisms;  has  an  ammoniacal  odor  and  an  alkaline  reaction; 
soluble  in  E^O.  By  exposure  to  air  or  by  heating  its  solution,  it  is 
decomposed  into  H2O,  NH3,  and  H(NH4)CO3.  It  is  not  a  pure  salt, 
but  a  mixture  of  monoammonic  carbonate  and  ammonium  carbamate. 

Analytical  Characters. — (1)  Entirely  volatile  at  high  tempera- 
tures. (2)  Heated  with  KHO,  the  ammoniacal  compounds  give  off 
NH3,  recognizable:  (a)  by  changing  moist  red  litmus  to  blue;  (b)  by 
its  odor;  (c)  by  forming  a  white  cloud  on  contact  with  a  glass  rod 
moistened  with  HC1.  (3)  With  platinic  chlorid:  a  yellow,  crystalline 
ppt.  (4)  With  hydrosodic  tartrate,  in  moderately  concentrated  and 
neutral  solution:  a  white  crystalline  ppt. 

Action  on  the  Economy. —  Solutions  of  the  hydroxid  and  car- 
bonate act  upon  animal  tissues  in  the  same  way  as  the  corresponding 
Na  and  K  compounds.  They,  moreover,  disengage  NH3,  which  causes 
intense  dyspnoea,  irritation  of  the  air -passages,  and  suffocation. 

The  treatment  indicated  is  the  neutralization  of  the  alkali  by  a 
dilute  acid.  Usually  the  vapor  of  acetic  acid  or  of  dilute  HC1  must 
be  administered  by  inhalation. 


188  MANUAL    OF    CHEMISTRY 

II.     THALLIUM  GROUP. 

THALLIUM. 

Symbol=T\— Atomic  weight=2M  (0=16:204.1;  H=l:202.48)- 
Sp,  0r.=11.8-11.9 — Fuses  at  294°  (561°  F.) — Discovered  by  Grooves 
(1861). 

A  rare  element,  first  obtained  from  the  deposits  in  flues  of  sul- 
furic  acid  factories,  in  which  pyrites  from  the  Hartz  were  used.  It 
resembles  Pb  in  appearance  and  in  physical  properties,  but  differs 
entirely  from  that  element  in  its  chemical  characters.  It  resembles 
Au  in  being  univaleut  and  trivalent,  but  differs  from  it,  and  resem- 
bles the  alkali  metals  in  being  readily  oxidized,  in  forming  alums,  and 
in  forming  no  acid  hydrate.  It  differs  from  the  alkali  metals  in  the 
thallic  compounds,  which  contain  Tl' " '.  It  is  characterized  spectro- 
scopically  by  a  bright  green  line — A.=5349. 


III.     CALCIUM   GROUP. 
Metals    of   the   Alkaline    Earths. 

CALCIUM — STRONTIUM— BARIUM. 

The  members  of  this  group  are  bivalent  in  all  their  compounds; 
each  forms  two  oxids:  MO  and  MO2;  each  forms  a  hydroxid,  having 
well-marked  basic  characters. 

CALCIUM. 

8ymbol=Csi— Atomic  weight=4Q  (O=16:40;  H=l:39.68)—  Mole- 
cular weight=8Q  (?) — Sp.  0rr.=1.984 — Discovered  by  Davy  in  1808 — 
Name  from  calx=lime. 

Occurs  only  in  combination,  as  limestone,  marble,  chalk  (CaCOs), 
gypsum,  selenite,  alabaster  (CaSOj,  and  many  other  minerals.  In 
bones,  egg-shells,  oyster -shells,  etc.,  as  Caa(PO4)2  and  CaCOs,  and 
in  many  vegetable  structures. 

The  element  is  obtained  by  electrolysis  of  fused  CaCl2,  or  by  heat- 
ing Cal2  with  Na.  It  is  a  hard,  yellow,  very  ductile,  and  malleable 
metal;  fusible  at  a  red  heat;  not  sensibly  volatile.  In  dry  air  it  is 
not  altered,  but  is  converted  into  CaH2O2  in  damp  air ;  decomposes 
H2O;  burns  when  heated  in  air. 

Calcium  Monoxid  —  Quick  Lime — Lime — Calx  (U.  S.;  Br.)  — 
CaO — 56 — is  prepared  by  heating  a  native  carbonate  (limestone) ;  or, 


CALCIUM  189 

when  required  pure,  by  heating  a  carbonate,  prepared   by  precipi- 
tation. 

It  occurs  in  white  or  grayish,  amorphous  masses;  odorless;  alka- 
line, caustic;  almost  infusible;  sp.  gr.  2.3.  With  H2O  it  gives  off 
great  heat  and  is  converted  into  the  hydroxid  (slaking).  In  air  it 
becomes  air- slaked,  falling  into  a  white  powder,  having  the  compo- 
sition CaCO3,  CaH202. 

Calcium  Hydroxid — Slaked  lime — Calcis  hydras  (Br.) — CaH2O2 
—74 — is  formed  by  the  action  of  H2O  on  CaO.  If  the  quantity  of 
H2O  used  be  one -third  that  of  the  oxid,  the  hydroxid  remains  as  a 
dry,  white,  odorless  powder  ;  alkaline  in  taste  and  reaction  ;  more 
soluble  in  cold  than  in  hot  H2O.  If  the  quantity  of  H2O  be  greater, 
a  creamy  or  milky  liquid  remains,  cream,  or  milk  of  lime;  a  solu- 
tion holding  an  excess  in  suspension.  With  a  sufficient  quantity  of 
EE20  the  hydroxid  is  dissolved  to  a  clear  solution,  which  is  lime  water 
—Liquor  calcis  (U.  S.;  Br.).  The  solubility  of  CaH2O2  is  dimin- 
ished by  the  presence  of  alkalies,  and  is  increased  by  sugar  or  man- 
nite;  Liq.  calc.  saccharatus  (Br.);  Syrupus  calcis  (U.  S.).  Solu- 
tions of  CaH2C>2  absorb  CO2  with  formation  of  a  white  deposit  of 
CaC03. 

Calcium  Carbide — CaC2 — is  formed  by  the  action  of  a  very  high 
temperature  upon  a  mixture  of  quick  lime  and  carbon.  It  is  an 
amorphous  grayish  substance,  which  is  decomposed  by  water,  yielding 
acetylene  gas:  CaC2+2H2O==C2H2+Ca(OH)2.  One  kilo.  CaC2  yields 
440  litres  C2H2. 

Calcium  Chlorid— Calcii  chloridum  (U.  S.;  Br.)—  CaCl2— 111— is 
obtained  by  dissolving  marble  in  HC1:  CaCO3-h2HCl=CaCl2+H2O+ 
CO2.  It  is  bitter,  deliquescent,  very  soluble  in  H2O;  crystallizes  with 
6Aq,  which  it  loses  when  fused,  leaving  a  white,  amorphous  mass, 
used  as  a  drying  agent. 

Chloride  of  Lime — Bleaching  powder — Calx  chlorata  (U.  S.; 
Br.) — is  a  white  or  yellowish,  hygroscopic  powder,  prepared  by 
passing  Cl  over  CaH2O2,  maintained  in  excess.  It  is  bitter  and  acrid 
in  taste;  soluble  in  cold  H2O;  decomposed  by  boiling  H2O,  and  by 
the  weakest  acids,  with  liberation  of  Cl.  It  is  decomposed  by  CO2, 
with  formation  of  CaCOs,  and  liberation  of  hypochlorous  acid,  if  it 
be  moist;  or  of  Cl,  if  it  be  dry.  A  valuable  disinfectant.  The  "avail- 
able chlorin"  is  the  amount  liberated  by  acids,  and  should  exceed  35%. 

Bleaching  powder  was  formerly  considered  as  a  mixture  of  calcium 
chlorid  and  hypochlorite,  formed  by  the  reaction  :  2CaO+2Cl2= 
CaCl2-fCa(C10)2,  but  it  is  more  probable  that  it  is  a  definite  com- 
pound having  the  formula  CaCl(OCl),  which  is  decomposed  by  H2O 
into  a  mixture  of  CaCl2  and  Ca(01O)2;  and  by  dilute  HNO3  or  H2SO4 
with  formation  of  HC1O. 


190  MANUAL    OF    CHEMISTRY 

Calcium  Sulfate — CaSCU — 136 — occurs  in  nature  as  a 
and  with  2Aq  in  gypsum,  alabaster,  selenite  ;  and  in  solution  in 
natural  waters.  Terra  alba  is  ground  gypsum.  It  crystallizes  with 
2Aq  in  right  rhombic  prisms;  sparingly  soluble  in  H2O,  more  soluble 
in  H2O  containing  free  acids  or  chlorids.  When  the  hydrated  salt 
(gypsum)  is  heated  to  80°  (176°  F.),  or,  more  rapidly,  between  120°- 
130°  (248°-266°  F.),  it  loses  its  Aq  and  is  converted  into  a  white, 
opaque  mass,  which,  when  ground,  is  plaster  of  Paris. 

The  setting  of  plaster  when  mixed  with  H2O,  is  due  to  the  con- 
version of  the  anhydrous  into  the  crystalline,  hydrated  salt.  The 
ordinary  plastering  should  never  be  used  in  hospitals,  as,  by  reason 
of  its  irregularities  and  porosity,  it  soon  becomes  saturated  with 
septic  germs,  and  cannot  be  thoroughly  purified  by  disinfectants. 
Plaster  surfaces  may,  however,  be  rendered  dense,  and  be  highly  pol- 
ished, so  as  to  be  smooth  and  impermeable,  by  adding  glue  and  alum, 
or  an  alkaline  silicate  to  the  water  used  in  mixing. 

Phosphates.— Three   are   known:    Ca3(PO4)2;   Ca2(HPO4)2,  and 

Ca(H2P04)2. 

Tricalcic  Phosphate — Tribasic  or  neutral  phosphate — Bone  phos- 
phate—  Calcii  phosphas  prsecipitatus  (U.  S.) — Calcis  phosphas 
(Br.) — Cas(P04)2 — 310 — occurs  in  nature,  in  soils,  guano,  coprolites, 
phosphorite,  in  all  plants,  and  in  every  animal  tissue  and  fluid.  It  is 
obtained  by  dissolving  bone -ash  in  HC1,  filtering,  and  precipitating 
with  NIUHO ;  or  by  double  decomposition  between  CaCl2  and  an  alka- 
line phosphate.  When  freshly  precipitated  it  is  gelatinous;  when 
dry,  a  light,  white,  amorphous  powder ;  almost  insoluble  in  pure 
H2O;  soluble  to  a  slight  extent  in  H2O  containing  ammoniacal  salts, 
or  NaCl  or  NaNOs ;  readily  soluble  in  dilute  acids,  even  in  H2O 
charged  with  carbonic  acid.  It.  is  decomposed  by  H2SO4  into  CaSCU 
and  Ca(H2PO4)2.  Bone-ash  is  an  impure  form  of  Ca3(PO4)2,  ob- 
tained by  calcining  bones,  and  used  in  the  manufacture  of  P  and  of 
superphosphate. 

Dicalcic  Phosphate— Ca2(HPO4)2+2Aq— 272+36— is  a  crystal- 
line, insoluble  salt;  formed  by  double  decomposition  between  CaCl2 
and  HNa2PO4  in  acid  solution. 

Monocalcic  Phosphate  —  Acid  calcium  phosphate  —  Superphos- 
phate of  lime — Ca(H2PO4)2 — 234 — exists  in  brain  tissue,  and  in  those 
animal  liquids  whose  reaction  is  acid.  It  is  also  formed  when 
CasfPOih  is  dissolved  in  an  acid,  and  is  manufactured  for  use  as  a 
manure,  by  decomposing  bone -ash  with  H2SO4.  It  crystallizes  in 
pearly  plates;  very  soluble  in  H2O.  Its  solutions  are  acid. 

Calcium  Carbonate — CaCOa — 100 — the  most  abundant  of  the 
natural  compounds  of  Ca,  exists  as  limestone,  calcspar,  chalk,  marble, 
Iceland  spar,  and  arragonite;  and  forms  the  basis  of  corals,  shells  of 


STRONTIUM  191 

Crustacea  and  of  molluscs,  etc.  Otoliths,  which  occur  in  the  internal 
ear,  parotid  calculi,  and  sometimes  vesical  calculi  consist  of  CaCOs. 

Precipitated  chalk — Calcii  carbonas  prsecipitata  (U.  S.  ;  Br.) 
—is  prepared  by  precipitating  a  solution  of  CaC^  with  one  of  Na2CO3. 
Prepared  chalk — Greta  praeparata  (U.  S.  ;  Br.)— is  native  chalk, 
purified  by  grinding  with  H2O,  diluting,  allowing  the  coarser  par- 
ticles to  subside,  decanting  the  still  turbid  liquid,  collecting  and 
drying  the  finer  particles.  A  process  known  as  elutriation  or  levi- 
gation. 

It  is  a  white  powder,  almost  insoluble  in  pure  EkO;  much  more 
soluble  in  EbO  containing  carbonic  acid,  the  solution  being  regarded 
as  containing  monocalcic  carbonate  EbCaCCOsh-  At  a  red  heat  it 
yields  C02  and  CaO.  It  is  decomposed  by  acids  with  liberation  of  CO2. 

Calcium  Oxalate  —  Oxalate  of  lime — CaC2O4 — 128  —  exists  in  the 
sap  of  many  plants,  in  human  urine,  and  in  mulberry  calculi,  and  is 
formed  as  a  white,  crystalline  precipitate,  by  double  decomposition, 
between  a  Ca  salt  and  an  alkaline  oxalate.  It  is  insoluble  in  H2O, 
acetic  acid,  or  NELtHO;  soluble  in  the  mineral  acids  and  in  solution 
of  H2NaPO4. 

Analytical  Characters. — (1)  Ammonium  sulfhydrate:  nothing, 
unless  the  Ca  salt  be  the  phosphate,  oxalate  or  fluorid,  when  it  forms 
a  white  ppt.  (2)  Alkaline  carbonates:  white  ppt.;  not  prevented  by 
the  presence  of  ammoniacal  salts.  (3)  Ammonium  oxalate:  white 
ppt.,  insoluble  in  acetic  acid;  soluble  in  HC1  or  HNOs.  (4)  Sulfuric 
acid:  white  ppt.,  either  immediately  or  on  dilution  with  three  volumes 
of  alcohol;  very  sparingly  soluble  in  EbO,  insoluble  in  alcohol;  sol- 
uble in  sodium  thiosulfate  solution.  (5)  Sodium  tungstate  :  dense 
white  ppt.,  even  from  dilute  solutions.  (6)  Colors  the  flame  of  the 
Bunsen  burner  reddish -yellow,  and  exhibits  a  spectrum  of  a  number 
of  bright  bands,  the  most  prominent  of  which  are:  A.=6265,  6202, 
6181,  6044,  5982,  5933,  5543,  and  5517. 


STRONTIUM. 

8ymbol=8r— Atomic  iveight=87.5  (0=16:86.9;  H=l:87.6)—  Sp. 
grr.=2.54. 

An  element,  not  as  abundant  as  Ba,  occurring  principally  in  the 
minerals  strontianite  (SrCO3)  and  celestine  (SrSO4).  Its  compounds 
resemble  those  of  Ca  and  Ba.  Its  nitrate  is  used  in  making  red  fire. 
The  iodid  and  the  lactate  are  used  in  medicine. 

Analytical  Characters. — (1)  Behaves  like  Ba  with  alkaline  car- 
bonates and  Na2HPO4.  (2)  Calcium  sulfate:  a  white  ppt.,  which 
forms  slowly;  accelerated  by  addition  of  alcohol.  (3)  The  Sr  com- 


192  MANUAL    OF    CHEMISTRY 

pounds  color  the  Bunsen  flame  red,  or,  as  observed  through  blue 
glass,  purple  or  rose  color.  The  Sr  flame  gives  a  spectrum  of  many 
bands,  of  which  the  most  prominent  are:  A.=6694,  6664,  6059,  6031, 
4607. 

BARIUM. 

8ymbol=Esi— Atomic  weight— 137.5  (O=16: 137.4  ;H=1:  136.3)- 
Molecularweight=273.6  (1)—Sp.  gr=4.Q— Discovered  by  Davy,  1808 
—Name  from  /fy>vs=  heavy. 

Occurs  only  in  combination,  principally  as  heavy  spar  (BaSOj 
and  witherite  (BaCOs).  It  is  a  pale  yellow,  malleable  metal,  quickly 
oxidized  in  air,  and  decomposing  EbO  at  ordinary  temperatures. 

Oxids. — Barium  Monoxid— Baryta — BaO— 153.4 — is  prepared  by 
calcining  the  nitrate.  It  is  a  grayish -white  or  white,  amorphous, 
caustic  solid.  In  air  it  absorbs  moisture  and  C02,  and  combines  with 
H2O  as  does  CaO. 

Barium  Dioxid — Barium  peroxid — BaO2 — 169.4  —  is  prepared  by 
heating  the  monoxid  in  O.  It  is  a  grayish -white,  amorphous  solid. 
Heated  in  air  it  is  decomposed:  BaC^^BaO+O.  Aqueous  acids  dis- 
solve it  with  formation  of  a  barytic  salt  and  H2O2. 

Barium  Hydroxid — BaH2O2— 171.5 — is  prepared  by  the  action  of 
EbO  on  BaO.  It  is  a  white,  amorphous  solid,  soluble  in  EbO.  Its 
aqueous  solution,  baryta  water,  is  alkaline,  and  absorbs  C02,  with 
formation  of  a  white  deposit  of  BaCOs. 

Barium  Chlorid— BaCl2-f2  Aq— 208.3+36— is  obtained  by  treat- 
ing BaS  or  BaCOa  with  HC1.  It  crystallizes  in  prismatic  plates,  per- 
manent in  air,  soluble  in  EbO. 

Barium  Nitrate — Ba(NOs)2 — 261.4  —  is  prepared  by  neutralizing 
HNOa  with  BaCOs.  It  forms  octahedral  crystals,  soluble  in  H^O. 

Barium  Sulfate — BaSO4 — 233.4 — occurs  in  nature  as  heavy  spar, 
and  is  formed  as  an  amorphous,  white  powder,  insoluble  in  acids,  by 
double  decomposition  between  a  Ba  salt  and  a  sulfate  in  solution.  It 
is  insoluble  in  EbO  and  in  acids.  It  is  used  as  a  pigment,  permanent 
white. 

Barium  Carbonate — BaCOs — 197.4 — occurs  in  nature  as  witherite, 
and  is  formed  by  double  decomposition  between  a  Ba  salt  and  a  car- 
bonate in  alkaline  solution.  It  is  a  heavy,  amorphous,  white  powder, 
insoluble  in  EhO,  soluble  with  effervescence  in  acids. 

Analytical  Characters. —  (1)  Alkaline  carbonates:  white  ppt.,  in 
alkaline  solution.  (2)  Sulfuric  acid,  or  calcium  sulfate:  white  ppt., 
insoluble  in  acids.  (3)  Sodium  phosphate:  white  ppt.,  soluble  in 
HNOs.  (4)  Colors  the  Bunsen  flame  greenish -yellow,  and  exhibits 
a  spectrum  of  several  lines,  the  most  prominent  of  which  are:  A=6108, 
6044,  5881,  5536. 


MAGNESIUM  193 

Action  on  the  Economy. — The  oxids  and  hydroxid  act  as  corro- 
sives, by  virtue  of  their  alkalinity,  and  also  as  true  poisons.  All 
soluble  compounds  of  Ba,  and  those  which  are  readily  converted  into 
soluble  compounds  in  the  stomach,  are  actively  poisonous.  Soluble 
sulfids,  followed  by  emetics,  are  indicated  as  antidotes.  The  sulfate, 
notwithstanding  its  insolubility  in  water,  is  poisonous  to  some  animals. 


IV.     MAGNESIUM   GROUP. 

MAGNESIUM — ZINC — CADMIUM . 

Each  of  these  elements  forms  a  single  oxid — a  corresponding  basic 
hydroxid,  and  a  series  of  salts  in  which  its  atoms  are  bivalent. 

The  existence  of  potassium  zincate,  ZnO2K2,  obtainable  by  the 
action  of  zinc  hydroxid  and  potassium  hydroxid  upon  each  other: 
Zn  ( OH )2+2KHO=ZnO2K2-f2H2O  would  seem  to  require  the  trans- 
ferral  of  zinc  to  the  amphoteric  class;  the  Zn  (OH) 2  in  the  above  reac- 
tion fulfilling  the  requirements  of  the  second  definition  of  acids  (see 
p.  42).  Potassium  zincate  should,  however,  be  considered  rather  as  a 
double  oxid  of  zinc  and  potassium:  ZnOK2O  or  Zn.OK.OK,  than  as 
a  true  salt  for  the  following  reasons:  (1)  It  is  also  produced  by  the 
reaction:  Zn-f2KHO=ZnO2K2+H2,  in  which,  if  ZnO2K2  be  a  salt, 
KHO,  the  most  distinctly  basic  substance  known,  must  be  considered 
to  be  an  acid.  (2)  In  the  electrolysis  of  ZnO2K2  the  Zn  and  K  go  to 
the  negative  pole,  and  the  O  to  the  positive,  while  in  the  electrolysis 
of  true  ternary  salts,  such  as  K2SO4,  the  oxygen  accompanies  the  other 
electro -negative  element  to  the  positive  pole,  the  metal  going  alone  to 
the  negative.  Moreover,  the  zincates  are  unstable  bodies,  and  the 
most  prominent  function  of  Zn(OH)2  is  that  of  a  base,  as  in  the 
reaction  Zn(OH)2+H2SO4—  ZnSO4+2HO2.  (See  Aluminium,  p.  198). 

MAGNESIUM. 

Symbol=1&g— Atomic  weight= 24  (0—16:24.36;  H=l:24.17)- 
Molecular  weight=4S  (t)—Sp.  gr=1.75— Fuses  at  1000°  (1832°  F.) 
— Discovered  by  Davy,  1808. 

Occurs  as  carbonate  in  dolomite  or  magnesian  limestone,  and  as 
silicate  in  mica,  asbestos,  soapstone,  meerschaum,  talc,  and  in  other 
minerals.  It  also  accompanies  Ca  in  the  forms  in  which  it  is  found 
in  the  animal  and  vegetable  worlds. 

It  is  prepared  by  heating  its  chlorid  with  Na,  or  by  electrolysis  of 
the  fused  chlorid.  It  is  a  hard,  light,  malleable,  ductile,  white  metal. 
It  burns  with  great  brilliancy  when  heated  in  air  (magnesium  light), 

13 


194  MANUAL    OF    CHEMISTRY 

but  may  be  distilled  in  H.  The  flash  light  used  by  photographers  is 
a  mixture  of  powdered  Mg  with  an  oxidizing  agent,  KClOs  or  KNO3. 
It  decomposes  vapor  of  EkO  when  heated;  reduces  CO2  with  the  aid 
of  heat,  and  combines  directly  with  01,  S,  P,  As  and  N.  It  dissolves 
in  dilute  acids,  but  is  not  affected  by  alkaline  solutions. 

Magnesium  Oxid— Calcined  magnesia— Magnesia  (U.  S,  ;  Br.) 
— MgO — 40 — is  obtained  by  calcining  the  carbonates,  hydroxid,  or 
nitrate.  It  is  a  light,  bulky,  tasteless,  odorless,  amorphous,  white 
powder;  alkaline  in  reaction;  almost  insoluble  in  EbO;  readily  sol- 
uble without  effervescence  in  acids. 

Magnesium  Hydroxid — MgH202 — 58 — occurs  in  nature,  and  is 
formed  when  a  solution  of  a  Mg  salt  is  precipitated  with  excess  of 
NaHO,  in  absence  of  ammoniacal  salts.  It  is  a  heavy,  white  powder, 
insoluble  in  H^O;  absorbs  C02. 

Magnesium  Chlorid— MgCk — 95 — is  formed  when  MgO  or  MgCOa 
is  dissolved  in  HC1.  It  is  an  exceedingly  deliquescent,  soluble  stb- 
stance,  which  is  decomposed  into  HC1  and  MgO  when  its  aqueous 
solutions  are  evaporated  to  dryness.  Like  all  the  soluble  Mg  com- 
pounds it  is  bitter  in  taste,  and  accompanies  the  sulfate  and  bicar- 
bonate in  the  Miter  waters. 

Magnesium  Sulfate — Epsom  salt — Seidlitz  salt — Magnesii  sulfas 
(U.  S.)  —  Magnesise  sulfas  (Br.)—MgSO4+7Aq— 120+126— exists 
in  solution  in  sea  water  and  in  the  waters  of  many  mineral  springs, 
especially  those  known  as  bitter  waters.  It  is  formed  by  the  action 
of  H2SO4  on  MgCOs.  It  crystallizes  in  right  rhombic  prisms;  bitter; 
slightly  effervescent,  and  quite  soluble  in  EbO.  Heated,  it  fuses  and 
gradually  loses  6Aq  up  to  132°  (269.6°  P.);  the  last  Aq  it  loses  at 
210°  (410°  P.). 

Phosphates. — Resemble  those  of  Ca  in  their  constitution  and 
properties,  and  accompany  them  in  the  situations  in  which  they  occur 
in  the  animal  body,  but  in  much  smaller  quantity. 

Magnesium  also  forms  double  phosphates,  constituted  by  the 
substitution  of  one  atom  of  the  bivalent  metal  for  two  of  the  atoms 
of  basic  hydrogen,  of  a  molecule  of  phosphoric  acid,  and  of  an  atom 
of  alkaline  metal,  or  of  an  ammonium  group,  for  the  remaining  basic 
hydrogen. 

Ammonio-Magnesian  Phosphate — Triple  phosphate — Mg(NH4)- 
PO4+6Aq — 137+108 — is  produced  when  an  alkaline  phosphate  and 
NELjHO  are  added  to  a  solution  containing  Mg.  When  heated  it  is 
converted  into  magnesium  pyrophosphate,  Mg2P2O?,  in  which  form 
HsPO4  and  Mg  are  usually  weighed  in  quantitative  analysis. 

Carbonates.— Magnesium  Carbonate— Neutral  carbonate— MgCO3 
—84 — exists  native  in  magnesite,  and,  combined  with  CaCOs,  in  dolo- 
mite. It  cannot  be  formed,  like  other  carbonates,  by  decomposing 


ZINC  195 

a  Mg  salt  with  an  alkaline  carbonate,  but  may  be  obtained  by  passing 
CO2  through  EbO  holding  tetramagnesic  tricarbonate  in  suspension. 

Trimagnesic  Bicarbonate  —  (MgCO3)2MgH2O2+2Aq— 226+36— 
is  formed,  in  small  crystals,  when  a  solution  of  MgSO4  is  precipitated 
with  excess  of  Na2COs,  and  the  mixture  boiled. 

Tetramagnesic  Tricarbonate — Magnesia  alba — Magnesii  carbo- 
nas  (U.  S.)— Magnesise  carbonas  (Br.)— (MgCO3)3MgH2O2+3Aq— 
310-J-54 — occurs  in  commerce  in  light,  white  cubes,  composed  of 
a  powder  which  is  amorphous,  or  partly  crystalline.  It  is  prepared 
by  precipitating  a  solution  of  MgSO*  with  one  of  Na2C(>3.  If  the 
precipitation  occur  in  cold,  dilute  solutions  (Magnesias  carbonas  loevis, 
Br.),  very  little  CO2  is  given  off;  a  light,  bulky  precipitate  falls,  and 
the  solution  contains  magnesium,  probably  in  the  form  of  the  bicar- 
bonate MgCHCOah.  This  solution,  on  standing,  deposits  crystals  of 
the  carbonate,  MgCOs+3Aq.  If  hot  concentrated  solutions  be  used, 
and  the  liquid  be  then  boiled  upon  the  precipitate,  C02  is  given  off, 
and  a  denser,  heavier  precipitate  is  formed,  which  varies  in  compo- 
sition, according  to  the  length  of  time  during  which  the  boiling  is 
continued,  and  to  the  presence  or  absence  of  excess  of  sodium  car- 
bonate. The  pharmaceutical  product  frequently  contains  (MgCOs)^ 
MgH2O2+4H2O,  or  even  (MgCO3)2,MgH2O2+2H2O.  All  of  these 
compounds  are  very  sparingly  soluble  in  EbO,  but  much  more  soluble 
in  EbO  containing  ammoniacal  salts. 

Analytical  Characters. —  (1)  Ammonium  hydroxid  :  voluminous, 
white  ppt.  from  neutral  solutions.  (2)  Potash  or  soda:  voluminous, 
white  ppt.  from  warm  solutions,  prevented  by  the  presence  of  NH4 
salts,  and  of  certain  organic  substances.  (3)  Ammonium  carbonate: 
slight  ppt.  from  hot  solutions  ;  prevented  by  the  presence  of  NH4 
salts.  (4)  Sodium  or  potassium  carbonate:  white  ppt  ,  best  from  hot 
solution;  prevented  by  the  presence  of  NH4  compounds.  (5)  Disodic 
phosphate:  white  ppt.  in  hot,  not  too  dilute  solutions.  (6)  Oxalic 
acid:  nothing  alone,  but  in  presence  of  NELtHO,  a  white  ppt.;  not 
formed  in  presence  of  salts  of  NELi. 

ZINC. 

Symbol=Zn— Atomic  weight  =  65  (O  =16:65.4  ;  H  =1:64. 88)- 
Molecular  weigM=65—Sp.  gr .=6 . 862-7 .215— Fuses  at  415°  (779°  F.) 
—Distils  at  1040°  (1904°  F.). 

Occurs  principally  in  calamine  (ZnCOs);  and  blende  (ZnS);  also 
as  oxid  and  silicate;  never  free.  It  is  separated  from  its  ores  by 
calcining,  roasting,  and  distillation. 

It  is  a  bluish -white  metal;  crystalline,  granular,  or  fibrous;  quite 
malleable  and  ductile  when  pure.  The  commercial  metal  is  usually 


196  MANUAL    OF    CHEMISTRY 

brittle.     At  130°-150°  (266°-302°  F.)  it  is  pliable,  and  becomes  brit- 
tle again  above  200°-210°  (392°-410°  P.). 

At  500°  (932°  F.)  it  burns  in  air,  with  a  greenish -white  flame, 
and  gives  off  snowy -white  flakes  of  the  oxid  (lana  philosophica ;  nil 
album;  pompholix) .  In  moist  air  it  becomes  coated  with  a  film  of 
hydrocarbonate.  It  decomposes  steam  when  heated. 

Pure  EbSCU  and  pure  Zn  do  not  react  together  in  the  cold.  If  the 
acid  be  diluted,  however,  it  dissolves  the  Zn,  with  evolution  of  H, 
and  formation  of  ZnS(>4,  in  the  presence  of  a  trace  of  Pt  or  Cu.  The 
commercial  metal  dissolves  readily  in  dilute  H2SO4,  with  evolution  of 
H,  and  formation  of  ZnSCU,  the  action  being  accelerated  in  presence 
of  Pt,  Cu,  or  As.  Zinc  surfaces,  thoroughly  coated  with  a  layer  of 
an  amalgam  of  Hg  and  Zn,  are  only  attacked  by  H2SO4  if  they  form 
part  of  closed  galvanic  circuit;  hence  the  zincs  of  galvanic  batteries 
are  protected  by  amalgamation.  Zinc  also  decomposes  HNO3,  HC1, 
and  acetic  acid.  Zinc  dissolves  in  strong  solutions  of  the  caustic 
alkalies  with  evolution  of  hydrogen  and  formation  of  double  oxids 
(zincates)  :  Zn+2KHO==ZnO2K2-|-H2.  It  also  decomposes  many 
metallic  salts  in  solution  with  deposition  of  the  metal. 

When  required  for  toxicological  analysis,  zinc  must  be  perfectly 
free  from  As,  and  sometimes  from  P.  It  is  better  to  test  samples 
until  a  pure  one  is  found,  than  to  attempt  the  purification  of  a  con- 
taminated metal. 

Zinc  surfaces  are  readily  attacked  by  weak  organic  acids.  Vessels 
of  galvanized  iron  or  sheet  zinc  should  therefore  never  be  used  to  con- 
tain articles  of  food  or  medicines. 

Zinc  Oxid — Zinci  oxidum  (U.  S.;  Br.) — ZnO — 81.4 — is  prepared 
either  by  calcining  the  precipitated  carbonate,  or  by  burning  Zn  in  a 
current  of  air.  An  impure  oxid,  known  as  tutty,  is  deposited  in  the 
flues  of  zinc  furnaces,  and  in  those  in  which  brass  is  fused.  When 
obtained  by  calcination  of  the  carbonate,  it  forms  a  soft,  white,  taste- 
less, and  odorless  powder.  When  produced  by  burning  the  metal,  it 
occurs  in  light,  voluminous,  white  masses.  It  is  neither  fusible, 
volatile,  nor  decomposable  by  heat,  and  is  completely  insoluble  in 
neutral  solvents.  It  dissolves  in  dilute  acids,  with  formation  of  the 
corresponding  salts. 

It  is  used  in  the  arts  of  a  white  pigment  in  place  of  lead  car- 
bonate, and  is  not  darkened  by  H2S. 

Zinc  Hydroxid — ZnH2O2 — 99.4 — is  not  formed  by  union  of  ZnO 
and  H2O;  but  is  produced  when  a  solution  of  a  Zn  salt  is  treated 
with  KHO.  Freshly  prepared,  it  is  very  soluble  in  alkalies,  and  in 
solutions  of  NH4  salts. 

Zinc  Chlorid — Butter  of  zinc— Zinci  chloridum  (U.  S.;  Br.)  — 
ZnCl2-hAq— 136.3+18— is  obtained  by  dissolving  Zn  in  HC1,  or  by 


ZINC  197 

heating  Zn  in  Cl.  It  is  a  soft,  white,  very  deliquescent,  fusible,  vola- 
tile mass;  very  soluble  in  EkO,  somewhat  less  so  in  alcohol.  Its 
solution  has  a  burning,  metallic  taste;  destroys  vegetable  tissues;  dis- 
solves silk;  and  exerts  a  strong  dehydrating  action  upon  organic  sub- 
stances in  general. 

In  dilute  solution  it  is  used  as  a  disinfectant  and  antiseptic  (Bur- 
nett's fluid) ,  as  a  preservative  of  wood  and  as  an  embalming  injection. 

Zinc  Sulfate— White  vitriol— Zinci  sulfas  (U.S.;  Br.)—  ZnSO4+ 
nAq— 161.4+wlS— is  formed  when  Zn,  ZnO,  ZnS,  or  ZnCO3  is  dis- 
solved in  diluted  H2S04.  It  crystallizes  below  30°  (86°  F. )  with  7  Aq ; 
at  30°  (86°  F.)  with  6  Aq;  between  40°-50°  (104°-122°  F.)  with 
5  Aq;  at  0°  (32°  F.)  from  concentrated  acid  solution  with  4  Aq. 
From  a  boiling  solution  it  is  precipitated  by  concentrated  H2SO4  with 
2  Aq;  from  a  saturated  solution  at  100°  (212°  F.)  with  1  Aq;  and 
anhydrous,  when  the  salt  with  1  Aq  is  heated  to  238°  (460°  F.). 

The  salt  usually  met  with  is  that  with  7  Aq,  which  is  in  large, 
colorless,  four -sided  prisms;  efflorescent;  very  soluble  in  H2O,  spar- 
ingly soluble  in  weak  alcohol.  Its  solutions  have  a  strong,  styptic 
taste :  coagulate  albumen  when  added  in  moderate  quantity,  the  coag- 
ulum  dissolving  in  an  excess;  and  form  insoluble  precipitates  with 
the  tannins. 

Carbonates. — Zinc  Carbonate — ZnCOs — 125.4 — occurs  in  nature 
as  calcimine.  If  an  alkaline  carbonate  be  added  to  a  solution  of  a  Zn 
salt,  the  neutral  carbonate,  as  in  the  case  of  Mg,  is  not  formed,  but 
an  oxycarbonate,  wZnCOa,  wZnH202  [Zinci  carbonas  (U.  S.;  Br.)], 
whose  composition  varies  with  the  conditions  under  which  it  is  formed. 

Analytical  Characters.— (1)  K,  Na  or  NH4  hydroxid:  white  ppt., 
soluble  in  excess.  (2)  Carbonate  of  K  or  Na:  white  ppt.,  in  absence 
of  NELt  salts.  (3)  Hydrogen  sulfid,  in  neutral  solution:  white  ppt. 
In  presence  of  an  excess  of  a  mineral  acid,  the  formation  of  this  ppt. 
is  prevented,  unless  sodium  acetate  be  also  present.  (4)  Ammonium 
sulf hydrate  :  white  ppt.,  insoluble  in  excess,  in  KHO,  NELiHO,  or 
acetic  acid  ;  soluble  in  dilute  mineral  acids.  (5)  Ammonium  car- 
bonate :  white  ppt.,  soluble  in  excess.  (6)  Disodic  phosphate,  in 
absence  of  NEU  salts  :  white  ppt.,  soluble  in  acids  or  alkalies.  (7) 
Potassium  ferrocyanid:  white  ppt.,  insoluble  in  HC1. 

Action  on  the  Economy. — All  the  compounds  of  Zn  which  are 
soluble  in  the  digestive  fluids  behave  as  true  poisons;  and  solutions 
of  the  chlorid  (in  common  use  by  tinsmiths,  and  in  disinfecting  fluids) 
have  also  well-marked  corrosive  properties.  When  Zn  compounds 
are  taken,  it  is  almost  invariably  by  mistake  for  other  substances:  the 
sulf  ate  for  Epsom  salt,  and  solutions  of  the  chlorid  for  various  liquids, 
such  as  gin,  fluid  magnesia,  vinegar,  etc. 

Metallic  zinc  is  dissolved  by  solutions  containing  NaCl,  or  organic 


198  MANUAL    OF    CHEMISTRY 

acids,  for  which  reason  articles  of  food  kept  in  vessels  of  galvanized 
iron  become  contaminated  with  zinc  compounds,  and,  if  eaten,  pro- 
duce more  or  less  intense  symptoms  of  intoxication.  For  the  same 
reason  materials  intended  for  analysis  in  cases  of  supposed  poisoning, 
should  never  be  packed  in  jars  closed  by  zinc  caps. 


CADMIUM. 

8ymbol=Cd— Atomic  weight=lll.5  (0=16:112.4;  H=l:111.5)- 
Molecular  tveight=lU.S—8p.  gr  =8.604:— Fuses  at  227.8°  (442°  F.) 
—Boils  at  860°  (1580°  F.). 

A  white  metal,  malleable  and  ductile  at  low  temperature,  brittle 
when  heated;  which  accompanies  Zn  in  certain  of  its  ores.  It  resem- 
bles zinc  in  its  physical  as  well  as  its  chemical  characters.  It  is  used 
in  certain  fusible  alloys,  and  its  iodid  is  used  in  photography. 

Analytical  Characters. — Hydrogen  sulfid:  bright  yellow  ppt.; 
insoluble  in  NIItHS,  and  in  dilute  acids  and  alkalies,  soluble  in  boil- 
ing HNO3  or  HC1. 


V.     ALUMINIUM  GROUP. 

BERYLLIUM — ALUMINIUM — SCANDIUM — GALLIUM — INDIUM. 

These  elements  form  one  series  of  compounds,  corresponding  to 
the  ferric,  containing  the  group  (M2)vi,  but  no  compounds  correspond- 
ing to  the  ferrous  M"  and  the  Ni  and  Co  salts  are  known.  Indeed, 
certain  organic  compounds,  such  as  aluminium  acetylacetonate, 
A1(C5H702)3,  seem  to  contain  single,  trivalent  atoms  of  the  metal. 
The  existence  of  the  aluminates,  such  as  K2A12O4,  would  seem  to  place 
aluminium  in  the  amphoteric  class.  These  compounds,  which  are 
formed  by  the  reactions  :  A12(OH)6+2KHO  =  K2A12O4  +  4H2O,  and 
A12+2KHO+2H2O=K2A12O4+3H2,  are  double  oxids  rather  than 
salts.  They  resemble  the  zincates  and  what  has  been  said  concerning 
those  compounds  (see  p.  193)  applies  also  to  the  aluminates. 


ALUMINIUM. 

Symbol  =  A1— Atomic  weight=21  (0  =  16:27.1;  H=l:26.88)- 
Molecular  weight=55  (?) — Sp.  gr.  =2. 56-2. 67 — Fuses  at  about  700° 
(1292°  F.) — Name  from  &\umen=alum— Discovered  by  Wohler,  1827. 

Occurrence. — Exceedingly  abundant  in  the  clays  as  silicate.  Also 
in  feldspar,  mica,  and  garnet,  topaz,  and  emerald.  As  a  fluorid  in 
cryolite,  and  as  a  hydroxid  in  beauxite. 


ALUMINIUM  199 

Preparation. —  (1)  By  decomposing  vapor  of  aluminium  chlorid 
by  Na  or  K  (Wohler).  (2)  Aluminium  hydroxid,  mixed  with  sodium 
chlorid  and  charcoal,  is  heated  in  Cl,  by  which  a  double  chlorid  of 
Na  and  Al  (Na2Al2Cls)  is  formed.  This  is  then  heated  with  Na, 
when  Al  and  NaCl  are  produced.  (3)  These  "chemical  methods" 
have  been  replaced,  in  the  industrial  preparation  of  aluminium,  by 
the  electrolytic  method,  in  which  a  mixture  of  cryolite  and  beauxite 
is  treated  in  an  electric  furnace. 

Properties. — Physical. — A  bluish- white  metal;  hard;  quite  mal- 
leable, and  ductile,  when  annealed  from  time  to  time;  slightly  mag- 
netic; a  good  conductor  of  electricity;  non- volatile;  very  light,  and 
exceedingly  sonorous. 

Chemical. — It  is  not  affected  by  air  or  O,  except  at  very  high  tem- 
peratures, and  then  only  superficially.  If,  however,  it  contain  Si,  it 
burns  readily  in  air,  forming  aluminium  silicate.  It  does  not  decom- 
pose H^O  at  a  red  heat;  but  in  contact  with  Cu,  Pt,  or  I,  it  does  so 
at  100°  (212°  F.).  It  combines  directly  with  B,  Si,  Cl,  Br,  and  I. 
It  is  attacked  by  HC1,  gaseous  or  in  solution,  with  evolution  of  H, 
and  formation  of  A^Cle.  It  dissolves  in  alkaline  solutions,  with 
formation  of  aluminates,  and  liberation  of  H.  It  alloys  with  Cu  to 
form  a  golden  yellow  metal  (aluminium  bronze) . 

Aluminium  Oxid — Alumina — A^Oa — 102.2  —  occurs  in  nature, 
nearly  pure,  as  corundum,  emery,  ruby,  sapphire,  and  topaz;  and  is 
formed  artificially,  by  calcining  the  hydrate,  or  ammonia  alum,  at  a 
red  heat. 

It  is  a  light,  white,  odorless,  tasteless  powder  ;  fuses  with  diffi- 
culty; and,  on  cooling,  solidifies  in  very  hard  crystals.  Unless  it 
has  been  heated  to  bright  redness,  it  combines  with  H^O,  with  eleva- 
tion of  temperature.  It  is  almost  insoluble  in  acids  and  alkalies. 
H2S04,  diluted  with  an  equal  bulk  of  IbO,  dissolves  it  slowly  as 
(Al2)  (804)3.  Fused  potash  and  soda  combine  with  it  to  form  alu- 
minates. It  is  not  reduced  by  charcoal. 

Aluminium  Hydroxid — Aluminium  hydrate — Aluminii  hydras 
(U.  S.) — A^HeOe — 156.2 — is  formed  when  a  solution  of  aluminium 
salt  is  decomposed  by  an  alkali,  or  alkaline  carbonate.  It  constitutes 
a  gelatinous  mass,  which,  when  dried,  leaves  an  amorphous,  translucid 
mass;  and,  when  pulverized,  a  white,  tasteless,  amorphous  powder. 
When  the  liquid  in  which  it  is  formed  contains  coloring  matters, 
these  are  carried  down  with  it,  and  the  dried  deposits  are  used  as 
pigments,  called  lakes. 

When  freshly  precipitated,  it  is  insoluble  in  H^O;  soluble  in 
acids,  and  in  solutions  of  the  fixed  alkalies.  When  dried  at  a  tem- 
perature above  50°  (122°  F.),  or  after  24  hours'  contact  with  the 
mother  liquor,  its  solubility  is  greatly  diminished.  With  acids  it 


200  MANUAL    OF    CHEMISTRY 

forms  salts  of  aluminium;  and  with  alkalies,  aluminates  of  the  alka- 
line metal.  Heated  to  near  redness,  it  is  decomposed  into  A12O3,  and 
H.2O.  A  soluble  modification  is  obtained  by  dialyzing  a  solution  of 
AloHeOe  in  AhCle,  or  by  heating  a  dilute  solution  of  aluminium  ace- 
tate for  24  hours. 

Aluminates  are  for  the  most  part  crystalline,  soluble  compounds, 
obtained  by  the  action  of  metallic  oxids  or  hydroxids  upon  alumina. 
Potassium  aluminate,  K2Al2O4+3Aq,  is  formed  by  dissolving 
recently  precipitated  aluminium  hydroxid  in  potash  solution.  It 
forms  white  crystals,  very  soluble  in  EbO,  insoluble  in  alcohol; 
caustic  and  alkaline.  By  a  large  quantity  of  H2O  it  is  decomposed 
into  aluminium  hydroxid  and  a  more  alkaline  salt,  KeAUOg. 

Sodium  Aluminate. — The  aluminate  NaeA^Oe  is  formed  when 
cryolite  is  heated  with  calcium  carbonate  (see  sodium  carbonate). 
Another  salt,  having  the  composition  Na6Al4O9,  is  prepared  by  heat- 
ing to  redness  a  mixture  of  1  pt.  sodium  carbonate  and  2  pts.  of  a 
native  ferruginous  aluminium  hydrate  (beauxite).  Both  salts  are 
soluble  in  H2O,  and  are  decomposed  by  carbonic  acid,  with  precipita- 
tion of  aluminium  hydroxid. 

Aluminium  Chlorid — Al2Cle — 266.9 — is  prepared  by  passing  Cl 
over  a  mixture  of  Al20s  and  C,  heated  to  redness,  or  by  heating  clay 
in  a  mixture  of  gaseous  HC1  and  vapor  of  €82. 

It  crystallizes  in  colorless,  hexagonal  prisms;  fusible;  volatile; 
deliquescent;  very  soluble  in  H2O  and  in  alcohol.  From  a  hot,  con- 
centrated solution,  it  separates  in  prisms  with  12 Aq.  At  very  high 
temperatures  A12C16  appears  to  be  dissociated  into  2A1C13. 

The  disinfectant  called  chtoralum  is  a  solution  of  impure  A12C16. 

Aluminium  Sulfate— Aluminii  sulfas  (U.  S.)-— (A12)  (SO4)3+ 
18Aq— 342.2+324— is  obtained  by  dissolving  A12H606  in  H2SO4;  or 
(industrially)  by  heating  clay  with  EbSCU. 

It  crystallizes,  with  difficulty,  in  thin,  flexible  plates;  soluble  in 
H2O;  very  sparingly  soluble  in  alcohol.  Heated,  it  fuses  in  its  Aq, 
which  it  gradually  loses  up  to  200°  (392°  F.),  when  a  white,  amor- 
phous powder,  (A12)  (864)3,  remains:  this  is  decomposed  at  a  red 
heat,  leaving  a  residue  of  pure  alumina. 

Alums  —  are  double  sulfates  of  the  alkaline  metals,  and  the 
higher  sulfates  of  this,  or  the  iron  group.  When  crystallized, 
they  have  the  general  formula:  (M2)vi  (SO4)3,  R'2SO4+24Aq,  in 
which  (M)  may  be  (Fe2),  (Mn2),  (Cr2),  (A12),  or  (Ga2);  and  R2  may 
be  K2,  Na2,  Rb2,  Cs2,  T12,  or  (NH4)2.  They  are  isomorphous  with 
each  other. 

Alumen  (U.  8.)—  A12(SO4)3,  K2SO4+24Aq— 516.5+432— is  man- 
ufactured from  "alum  shale,"  and  is  formed  when  solutions  of  the 
sulfates  of  Al  and  K  are  mixed  in  suitable  proportion. 


ALUMINIUM  201 

It  crystallizes  in  large,  transparent,  regular  octahedra;  has  a 
sweetish,  astringent  taste,  and  is  readily  soluble  in  H2O.  Heated,  it 
fuses  in  its  Aq  at  92  °  (197.6°  F.) ;  and  gradually  loses  45.5  per  cent, 
of  its  weight  of  H2O  ,  as  the  temperature  rises  to  near  redness.  The 
product,  known  as  burnt  alum  =  alumen  exsiccatum  (U.  S.),  is 
(A1)2(SO4)3,  K2SO4,  and  is  slowly,  but  completely,  soluble  in  20-30 
pts.  H2O.  At  a  bright  red  heat,  SO2  and  O  are  given  off,  and  Al2Oa 
and  potassium  sulfate  remain;  at  a  higher  temperature,  potassium 
aluminate  is  formed.  Its  solutions  are  acid  in  reaction;  dissolve  Zn 
and  Fe  with  evolution  of  H ;  and  deposit  A^HeOe  when  treated  with 
ammonium  hydroxid. 

Alumen  (Br.)—  A12(SO4)3,  (NH4)2SO4+24Aq— 474.2+432— is  the 
compound  now  usually  met  with  as  alum,  both  in  this  country  and  in 
England.  It  differs  from  potash  alum  in  being  more  soluble  in  H2O, 
between  20°-30°  (68°-86°  F.),  and  less  soluble  at  other  temperatures ; 
and  in  the  action  of  heat  upon  it.  At  92°  (197.6°  F.)  it  fuses  in 
its  Aq;  at  205°  (401°  F.),  it  loses  its  ammonium  sulfate,  leaving  a 
white,  hygroscopic  substance,  very  slowly  and  incompletely  soluble 
in  H2O.  More  strongly  heated,  it  leaves  alumina.  Alum  is  used  in 
dyeing,  and  in  purification  of  water  by  precipitation. 

Silicates — are  very  abundant  in  the  different  varieties  of  day, 
feldspar,  albite,  labradorite,  mica,  etc.  The  clays  are  hydrated  alu- 
minium silicates,  more  or  less  contaminated  with  alkaline  and  earthy 
salts  and  iron,  to  which  last  certain  clays  owe  their  color.  The  purest 
is  kaolin,  or  porcelain  clay,  a  white  or  grayish  powder.  They  are 
largely  used  in  the  manufacture  of  the  different  varieties  of  bricks, 
terra  cotta,  pottery,  and  porcelain.  Porcelain  is  made  from  the  purer 
clays,  mixed  with  sand  and  feldspar;  the  former  to  prevent  shrinkage, 
the  latter  to  bring  the  mixture  into  partial  fusion,  and  to  render  the 
product  translucent.  The  fashioned  articles  are  subjected  to  a  first 
baking.  The  porous,  baked  clay  is  then  coated  with  a  glaze,  usually 
composed  of  oxid  of  lead,  sand  and  salt.  During  a  second  baking 
the  glaze  fuses,  and  coats  the  article  with  a  hard,  impermeable  layer. 
The  coarser  articles  of  pottery  are  glazed  by  throwing  sodium  chlorid 
into  the  fire;  the  salt  is  volatilized,  and  on  contact  with  the  hot  alu- 
minium silicate,  deposits  a  coating  of  the  fusible  sodium  silicate, 
which  hardens  on  cooling. 

Analytical  Characters. — (1)  Potash,  or  soda:  white  ppt.,  soluble 
in  excess.  (2)  Ammonium  hydroxid:  white  ppt.,  almost  insoluble  in 
excess,  especially  in  presence  of  ammoniacal  salts.  (3)  Sodium  phos- 
phate: white  ppt.,  readily  soluble  in  KHO  and  NaHO,  but  not  in 
NH4HO;  soluble  in  mineral  acids,  but  not  in  acetic  acid.  (4)  Blow- 
pipe— on  charcoal  does  not  fuse,  and  moistened  with  cobalt  nitrate 
solution  turns  dark  sky-blue. 


202 


MANUAL    OF    CHEMISTRY 


BERYLLIUM — SCANDIUM — GALLIUM — INDIUM. 

Symbols  and  atomic  weights—  Be(Gl) ;  9— Sc;  45— Ga;  70— In;  114. 

These  elements  occur  in  nature  in  very  small  quantities :  Beryllium 
in  the  emerald  and  beryl;  scandium  in  gadolinite  and  euxenite;  gal- 
lium and  indium  in  certain  zinc  blendes.  Beryllium,  also  called  Glu- 
cinium, the  most  abundant  of  the  group,  was  discovered  by  Vauque- 
lin,  in  1797;  the  others  have  been  discovered  by  spectroscopic  meth- 
ods; scandium  by  Nilson,  in  1879;  gallium  by  Boisbaudran,  in  1876, 
and  indium  by  Reich  and  Richter,  in  1863. 

The  discovery  of  Sc  and  Ga  affords  most  flattering  verifications 
of  predictions  based  upon  purely  theoretical  considerations. 

It  has  been  observed  that  there  exist  numerical  relations  between 
the  atomic  weights  of  the  elements,  which,  in  groups  of  allied  ele- 
ments differ  from  each  other  by  (approximately)  some  multiple  of 
eight.  Upon  this  variation  Mendelejeff  has  based  what  is  known  as  the 
Periodic  Law,  to  the  effect  that:  "The  properties  of  elements,  the 
constitution  of  their  compounds  and  the  properties  of  the  latter, 
are  periodic  functions  of  the  atomic  weights  of  the  elements." 

In  accordance  with  this  law  the  elements  may  be  thus  arranged: 


Series. 

Group 

Group 
II. 

Group 
III. 

Group 
IV. 

Group 

Group 
VI. 

Group 
VII. 

Group 
VIII. 

RH4 

RHa 

RH2 

RH 

(R2H) 

1 

R2O 
H—  1 

RO 

R203 

RO2 

R2O5 

RO3 

R207 

(R04) 

2 

Li—  7 

Be—  9 

B=ll 

C—  12 

N=14 

O—  16 

F=19 

3  
4                        * 

Na=23 
K—  39 

Mg=24 
Ca~  40 

Al=27 
Sc~  44 

Si=28 
Ti—  48 

P=31 
y—  51 

S=32 
Cr—  52 

Cl=35 

Mn~  55 

Cu=63 
Fe-=56 
Co=59 

Ni=59 

5  
6  

(Cu=63) 
Rb=85 

Zn=65 
Sr=87 

XJa=69 

Yt=88 

Ge=72 
Zr=90 

As=75 
Nb=94 

Se=78 
Mo=96 

Br=80 
?=100 

Ru=101 

Pd=106 
Ag=108 

7 

(Ag  —  108) 

Cd=112 

In  —  113 

Sn  —  118 

Sb—  120 

Te  —  195 

1=127 

Rh—  139 

8  

Cs—  133 

Ba=137 

La—  137 

Ce  —  139 

Nd  —  143 

Sm—  150 

9  

E—  166 

Os=191 

10  

¥5=172 

Ta~  182 

W—  184 

?—  190 

Ir=192 
Pt=193 

Au=196 

11  .   . 

(Au=196) 

Hg=«>00 

Tl  —  204 

Pb  —  207 

BJ—  208 

12  

Th=231 

TJ—  238 

The  atomic  weights  and  chemical  characters,  which  were  announced 
by  Mendelejeff  in  1870  as  those  of  the  undiscovered  elements  which 
would  occupy  the  positions  4  and  5  in  Group  III,  have  been  since  found 
to  be  those  of  Sc  and  Ga.  Still  later,  the  vacant  positions  10,  III,  5, 
IV,  and  8,  VI,  have  been  filled  by  the  discovery  of  Yb,  Ge,  and  Sm. 


NICKEL— COBALT  203 

VI.     NICKEL   GROUP. 

NICKEL — COBALT. 

These  two  elements  bear  some  resemblance  chemically  to  those  of 
the  Fe  group;  from  which  they  differ  in  forming,  so  far  as  known, 
no  compounds  similar  to  the  ferrates,  chromates,  and  manganates, 
unless  the  barium  cobaltite,  described  by  Rousseau,  be  such.  They 
form  compounds  corresponding  to  Fe2Os,  but  those  corresponding  to 
the  ferric  salts  are  either  wanting  or  exceedingly  unstable. 

NICKEL. 

8ymlol='Ni=Atomic  weight=58  (0=16:58.7;  H=l : 58.22)—  Sp. 
0r,=8.637. 

Occurs  in  combination  with  S,  and  with  S  and  As. 

It  is  a  white  metal,  hard,  slightly  magnetic,  not  tarnished  in  air. 
German  silver  is  an  alloy  of  Ni,  Cu,  and  Zn.  Nickel  is  now  exten- 
sively used  for  plating  upon  other  metals,  and  for  the  manufacture  of 
dishes,  etc.,  for  use  in  the  laboratory.  Its  salts  are  green. 

Nickelous  Sulfate — NiSO4 — is  obtained  by  dissolving  the  metal, 
hydroxid  or  carbonate  in  EbSOi.  It  forms  green  crystals  with  7  Aq, 
and  combines  with  (NH4)2SO4  to  form  a  double  sulfate,  used  in  the 
nickel-plating  bath,  for  which  use  it  must  be  free  from  K  or  Na. 

Analytical  Characters. —  (1)  Ammonium  sulf hydrate:  black  ppt.; 
insoluble  in  excess.  (2)  Potash  or  soda:  apple -green  ppt.,  in  ab- 
sence of  tartaric  acid;  insoluble  in  excess.  (3)  Ammonium  hydroxid: 
apple-green  ppt.;  soluble  in  excess;  forming  a  violet  solution,  which 
deposits  the  apple -green  hydrate,  when  heated  with  KHO. 

COBALT. 

Symbol=Co— Atomic  weight=59  (O=16:59;  H=59.53)—  8p.gr. = 

8.5-8.7. 

Occurs  in  combination  with  As  and  S.  Its  salts  are  red  when 
hydrated,  and  usually  blue  when  anhydrous.  Its  phosphate  is  used 
as  a  blue  pigment. 

Analytical  Characters. — (1)  Ammonium  sulf  hydrate:  black  ppt.; 
insoluble  in  excess.  (2)  Potash:  blue  ppt.;  turns  red,  slowly  in  the 
cold,  quickly  when  heated;  not  formed  in  the  cold  in  the  presence  of 
NH4  salts.  (3)  Ammonium  hydroxid:  blue  ppt.;  turns  red  in  ab- 
sence of  air,  green  in  its  presence. 


204  MANUAL    OF    CHEMISTRY 

VII.     COPPER   GROUP. 

COPPER — MERCURY. 

Each  of  these  elements  forms  two  series  of  compounds.      One 

(Cu\ \  " 
Cu/yor  (H&a)",  wnich 

are  designated  by  the  termination  ous ;  the  other  contains  compounds 
of  single,  bivalent  atoms  Cu"  or  Hg",  which  are  designated  by  the 
termination  ic. 

COPPER. 

Symbol=Ca  (Cuprum)— Atomic  weight=63  (0—16:63.6;  H= 
1:63.09)—  Molecular  weight=127  CD—tip.  ^.  =  8.914-8.952—  Fuses 
at  1091°  (1996°  F.). 

Occurrence. — It  is  found  free,  in  crystals  or  amorphous  masses, 
sometimes  of  great  size;  also  as  sulfid,  copper  pyrites  ;  oxid,  ruby  ore 
and  black  oxid  ;  and  basic  carbonate,  malachite. 

Properties. — Physical. — A  yellowish-red  metal;  dark -brown  when 
finely  divided  ;  very  malleable,  ductile,  and  tenacious;  a  good  con- 
ductor of  heat  and  electricity ;  has  a  peculiar,  metallic  taste  and  a 
characteristic  odor. 

Chemical. — It  is  unaltered  in  dry  air  at  the  ordinary  temperature; 
but,  when  heated  to  redness,  is  oxidized  to  CuO.  In  damp  air  it 
becomes  coated  with  a  brownish  film  of  oxid;  a  green  film  of  basic 
carbonate;  or,  in  salt  air,  a  green  film  of  basic  chlorid.  Hot  H2&O4 
dissolves  it  with  formation  of  CuSO4  and  SO2.  It  is  dissolved  by 
HNO3  with  formation  of  Cu(NO3)2  and  NO;  and  by  HC1  with  libera- 
tion of  H.  Weak  acids  form  with  it  soluble  salts,  in  presence  of  air 
and  moisture.  It  is  dissolved  by  NH4HO,  in  presence  of  air,  with 
formation  of  a  blue  solution.  It  combines  directly  with  Cl,  fre- 
quently with  light. 

Oxids. —  Cuprous  Oxid — Suboxid  or  red  oxid  of  copper — (Cu2)O 
— 143.2  —  is  formed  by  calcining  a  mixture  of  (Cu2)Cl2  and  Na2COs; 
or  a  mixture  of  CuO  and  Cu.  It  is  a  red  or  yellow  powder;  per- 
manent in  air;  sp.  gr.  5.749-6.093;  fuses  at  a  red  heat;  easily 
reduced  by  C  or  H.  Heated  in  air  it  is  converted  into  CuO. 

Cupric  Oxid—Binoxid  or  black  oxid  of  copper — CuO — 79.6  —  is 
prepared  by  heating  Cu  to  dull  redness  in  air;  or  by  calcining 
Cu(NO3)2;  or  by  prolonged  boiling  of  the  liquid  over  a  precipitate, 
produced  by  heating  a  solution  of  a  cupric  salt,  in  presence  of 
glucose,  with  KHO.  By  the  last  method  it  is  sometimes  produced 
in  Trommer's  test  for  glucose,  when  an  excessive  quantity  of  CuSO4 
has  been  used. 


COPPER  205 

It  is  a  black,  or  dark  reddish -brown,  amorphous  solid;  readily 
reduced  by  C,  H,  Na,  or  K  at  comparatively  low  temperatures.  When 
heated  with  organic  substances,  it  gives  up  its  O,  converting  the  C 
into  CO2,  and  the  H  into  H2O:  C2H6O-h6CuO=6Cu+2CO2+3H2O; 
a  property  which  renders  it  valuable  in  organic  analysis,  as  by  heat- 
ing a  known  weight  of  organic  substance  with  CuO,  and  weighing 
the  amount  of  CO2  and  H20  produced,  the  percentage  of  C  and  H 
may  be  obtained.  It  dissolves  in  acids  with  formation  of  salts. 

Hydroxids.— Cuprous  Hydroxid  — (Cu)2H2O2(?)— 160.4  (?)— is 
formed  as  a  yellow  or  red  powder  when  mixed  solutions  of  CuSCU 
and  KHO  are  heated  in  presence  of  glucose.  By  boiling  the  solution 
it  is  rapidly  dehydrated  with  formation  of  (Cu2)O. 

Cupric  Hydroxid — CuH2O2 — 97.6  —  is  formed  by  the  action  of 
KHO  upon  solution  of  CuSO4,  in  absence  of  reducing  agents  and  in 
the  cold.  It  is  a  bluish,  amorphous  powder;  very  unstable,  and 
readily  dehydrated,  with  formation  of  CuO. 

Sulfids. —  Cuprous  Sulfid — Siibsulfid  or  protosulfid  of  copper — 
Cu2S — 159.2 — occurs  in  nature  as  copper  glance  or  chalcosine,  and  in 
many  double  sulflds,  pyrites. 

Cupric  Sulfid — CuS — 95.6 — is  formed  by  the  action  of  H2S,  or  of 
NH4HS,  on  solutions  of  cupric  salts.  It  is  almost  black  when  moist, 
greenish -brown  when  dry.  Hot  HNO.s  oxidizes  it  to  CuSO4;  hot 
HC1  converts  it  into  CuCl2,  with  separation  of  S,  and  formation  of 
H2S.  It  is  sparingly  soluble  in  NH4HS,  its  solubility  being  increased 
by  the  presence  of  organic  matter. 

Chlorids. —  Cuprous  Chlorid — Subcklorid  or  protochlorid —  (Cu2) 
C12 — 198.1 — is  prepared  by  heating  Cu  with  one  of  the  chlorids  of 
Hg;  by  dissolving  (Cu2)O  in  HC1,  without  contact  of  air;  or  by  the 
action  of  reducing  agents  on  solutions  of  CuCl2.  It  is  a  heavy,  white 
powder;  turns  violet  and  blue  by  exposure  to  light;  soluble  in  HC1; 
insoluble  in  H2O.  It  forms  a  crystallizable  compound  with  CO;  and 
its  solution  in  HC1  is  used  in  analysis  to  absorb  that  gas. 

Cupric  Chlorid — Chlorid  or  deutoMorid — CuCl2 — 134.5 — is  formed 
by  dissolving.  Cu  in  aqua  regia.  If  the  Cu  be  in  excess,  it  reduces 
CuCl2  to  (Cu2)Cl2.  It  crystallizes  in  bluish -green,  rhombic  prisms 
with  2  Aq;  deliquescent;  very  soluble  in  H2O  and  in  alcohol. 

Cupric  Nitrate — Cu(NOs)2 — 187.6 — is  formed  by  dissolving  Cu, 
CuO,  or  CuC03  in  HNO3.  It  crystallizes  at  20°-25°  (68°-77°  F.) 
with  3  Aq;  below  20°  (68°  F.)  with  6  Aq,  forming  blue,  deliquescent 
needles.  Strongly  heated,  it  is  converted  into  CuO. 

Cupric  Sulfate — Blue  vitriol — Blue  stone — Cupri  sulfas  (U.  S.; 
Br.)—CuSO4+5Aq— 159.6+90— is  prepared:  (1)  by  roasting  CuS; 
(2)  from  the  water  of  copper  mines;  (3)  by  exposing  Cu,  moistened 
with  dilute  H2S04,  to  air;  (4)  by  heating  Cu  with  H2SO4. 


206  MANUAL    OF    CHEMISTRY 

As  ordinarily  crystallized,  it  is  in  fine,  blue,  oblique  prisms;  solu- 
ble in  EbO;  insoluble  in  alcohol;  efflorescent  in  dry  air  at  15°  (59° 
F.),  losing  2  Aq.  At  100°  (212°  F.)  it  still  retains  1  Aq,  which  it 
loses  at  230°  (446°  F.),  leaving  a  white,  amorphous  powder  of  the 
anhydrous  salt,  which,  on  taking  up  fl^O,  resumes  its  blue  color. 
Its  solutions  are  blue,  acid,  styptic,  and  metallic  in  taste. 

When  NELtHO  is  added  to  a  solution  of  CuSCU,  a  bluish -white 
precipitate  falls,  which  redissolves  in  excess  of  the  alkali,  to  form  a 
deep  blue  solution.  Strong  alcohol  floated  over  the  surface  of  this 
solution  separates  long,  right  rhombic  prisms,  having  the  composi- 
tion CuSO4,4NH3+H2O,  which  are  very  soluble  in  H20.  This  solu- 
tion constitutes  ammonio-sulfate  of  copper  or  aqua  sapphirina. 

Cupric  Arsenite — Scheele's  green  —  Mineral  green  —  is  a  mix- 
ture of  cupric  arsenite,  HCuAsOa,  and  hydroxid;  prepared  by  adding 
potassium  arsenite  to  solution  of  CuSC>4.  It  is  a  grass -green  powder, 
insoluble  in  IbO;  soluble  in  NH4HO,  or  in  acids.  Exceedingly 
poisonous. 

Schweinfurt  Green  —  Mitis  green  or  Paris  green  —  is  the  most 
frequently  used,  and  the  most  dangerous  of  the  cupro- arsenical  pig- 
ments. It  is  prepared  by  adding  a  thin  paste  of  neutral  cupric 
acetate  with  H2O  to  a  boiling  solution  of  arsenous  acid,  and  con- 
tinuing the  boiling  during  a  further  addition  of  acetic  acid.  It  is 
an  insoluble,  green,  crystalline  powder,  having  the  composition 
(C2H302)2Cu+3Cu(AsO2)2,  and  is  therefore  cupric  aceto-metarsenite. 
It  is  decomposed  by  prolonged  boiling  in  H2O,  by  aqueous  solutions 
of  the  alkalies,  and  by  the  mineral  acids. 

Carbonates. — The  existence  of  cuprous  carbonate  is  doubtful. 
Cupric  carbonate — CuCOa  —  exists  in  nature,  but  has  not  been  ob- 
tained artificially.  Dicupric  carbonate  —  CuCO3,CuH2O2  —  exists  in 
nature  as  malachite.  When  a  solution  of  a  cupric  salt  is  decomposed 
by  an  alkaline  carbonate,  a  bluish  precipitate,  having  the  composition 
CuCO3,CuH2O2+  EkO,  is  formed,  which,  on  drying,  loses  EbO,  and 
becomes  green;  it  is  used  as  a  pigment  under  the  name  mineral 
green.  Tricupric  carbonate  — Sesquicarbonate  of  copper-^- 2  ( CuCOs) , 
CuH2O2  —  exists  in  nature  as  a  blue  mineral,  called  azurite  or  moun- 
tain blue,  and  is  prepared  by  a  secret  process  for  use  as  a  pigment 
known  as  blue  ash. 

Acetates. —  Cupric  Acetate — Diacetate  — Crystals  of  Venus — Cupri 
acetas  (U.  S.)—Cu(C2H3O2)2+Aq— 181.6+18— is  formed  when  CuO 
or  verdigris  is  dissolved  in  acetic  acid;  or  by  decomposition  of  a 
solution  of  CuSO4  by  Pb(C2H3O2)2.  It  crystallizes  in  large,  bluish- 
green  prisms,  which  lose  their  Aq  at  140°  (284°F.).  At  240°-260° 
(464°-500°  F.)  they  are  decomposed  with  liberation  of  glacial  acetic 
acid. 


COPPER  207 

Basic  Acetates. — Verdigris — is  a  substance  prepared  by  exposing 
to  air  piles  composed  of  alternate  layers  of  grape -skins  and  plates 
of  copper,  and  removing  the  bluish -green  coating  from  the  copper. 
It  is  a  mixture,  in  varying  proportions,  of  three  different  sub- 
stances: (C2H3O2)2Cu2H2O2+5Aq;  [(C2H3O2)2Cu]2,CuH2O2+5Aq;  and 
(C2H3O2)2Cu,2(CuH2O2). 

Analytical  Characters. —  CUPROUS — are  very  unstable  and  readily 
converted  into  cupric  compounds.  (1)  Potash:  white  ppt.;  turning 
brownish.  (2)  Ammonium  hydroxid,  in  absence  of  air:  a  colorless 
liquid;  turns  blue  in  air. 

CUPRIC  —  are  white  when  anhydrous;  when  soluble  in  H20  they 
form  blue  or  green,  acid  solutions.  (1)  Hydrogen  sulfid:  black  ppt.; 
insoluble  in  KHS  or  NaHS;  sparingly  soluble  in  NELiHS;  soluble  in 
hot  concentrated  HNO3  and  in  KCN.  (2)  Alkaline  sulf hydrates : 
same  as  H2S.  (3)  Potash  or  soda:  pale  blue  ppt.;  insoluble  in 
excess.  If  the  solution  be  heated  over  the  ppt.,  the  latter  contracts 
and  turns  black.  (4)  Ammonium  hydroxid,  in  small  quantity:  pale 
blue  ppt.;  in  larger  quantity:  deep  blue  solution.  (5)  Potassium  or 
sodium  carbonate:  greenish -blue  ppt.;  insoluble  in  excess;  turning 
black  when  the  liquid  is  boiled.  (6)  Ammonium  carbonate:  pale 
blue  ppt.;  soluble  with  deep  blue  color  in  excess.  (7)  Potassium 
cyanid:  greenish  -yellow  ppt. ;  soluble  in  excess.  (8)  Potassium  fer- 
rocyanid:  chestnut -brown  ppt.;  insoluble  in  weak  acids;  decolorized 
by  KHO.  (9)  Iron  is  coated  with  metallic  Cu. 

Action  on  the  Economy. — The  opinion,  formerly  universal  among 
toxicologists,  that  all  the  compounds  of  copper  are  poisonous,  has 
been  much  modified  by  later  researches.  Certain  of  the  copper 
compounds,  such  as  the  sulf  ate,  having  a  tendency  to  combine  with 
protein  and  other  animal  substances,  produce  symptoms  of  irrita- 
tion by  their  direct  local  action,  when  brought  in  contact  with  the 
gastric  or  intestinal  mucous  membrane.  One  of  the  characteristic 
symptoms  of  such  irritation  is  the  vomiting  of  a  greenish  matter, 
which  develops  a  blue  color  upon  the  addition  of  NHtHO. 

Cases  are  not  wanting  in  which  severe  illness,  and  even  death,  has 
followed  the  use  of  food  which  has  been  in  contact  with  imperfectly 
tinned  copper  vessels.  Cases  in  which  nervous  and  other  symptoms 
referable  to  a  truly  poisonous  action  have  occurred.  As,  however,  it 
has  also  been  shown  that  non- irritant,  pure  copper  compounds  may 
be  taken  in  considerable  doses  with  impunity,  it  appears  at  least 
probable  that  the  poisonous  action  attributed  to  copper  is  due  to 
other  substances.  The  tin  and  solder  used  in  the  manufacture  of 
copper  utensils  contain  lead,  and  in  some  cases  of  so-called  copper- 
poisoning,  the  symptoms  have  been  such  as  are  as  consistent  with 
lead -poisoning  as  with  copper -poisoning.  Copper  is  also  notoriously 


208  MANUAL    OF    CHEMISTRY 

liable  to  contamination  with  arsenic,  and  it  is  by  no  means  im- 
probable that  compounds  of  that  element  are  the  active  poisonous 
agents  in  some  cases  of  supposed  copper- intoxication.  Nor  is  it 
improbable  that  articles  of  food  allowed  to  remain  exposed  to  air  in 
copper  vessels  should  undergo  those  peculiar  changes  which  result 
in  the  formation  of  poisonous  substances,  such  as  the  sausage-  or 
cheese -poisons,  or  the  ptomains. 

The  treatment,  when  irritant  copper  compounds  have  been  taken, 
should  consist  in  the  administration  of  white  of  egg  or  of  milk,  with 
whose  proteins  an  inert  compound  is  formed  by  the  copper  salt. 
If  vomiting  do  not  occur  spontaneously,  it  should  be  induced  by  the 
usual  methods. 

The  detection  of  copper  in  the  viscera  after  death  is  not  without 
interest,  especially  if  arsenic  have  been  found,  in  which  case  its 
discovery  or  non- discovery  enables  us  to  differentiate  between  poison- 
ing by  the  arsenical  greens,  and  that  by  other  arsenical  compounds. 
The  detection  of  mere  traces  of  copper  is  of  no  significance,  because, 
although  copper  is  not  a  physiological  constituent  of  the  body,  it  is 
almost  invariably  present,  having  been  taken  with  the  food. 

Pickles  and  canned  vegetables  are  sometimes  intentionally  greened 
by  the  addition  of  copper;  this  fraud  is  readily  detected  by  inserting 
a  large  needle  into  the  pickle  or  other  vegetable;  if  copper  be  present 
the  steel  will  be  found  to  be  coated  with  copper  after  half  an  hour's 
contact. 

MERCURY. 

Symbol=Kg  (Hydrargyrum)— Atomic  weight=200  (0=16:200.3; 
H=l:198.7)— Molecular  weight=l9S.7—Sp.  gr.  of  liquid=13.596  ;  of 
vapor=6. 97— Fuses  at  —38.8°  (—37.9°  F.)—  Boils  at  358°  (676.4° 
F.). 

Occurrence. — Chiefly  as  cinnabar  (HgS);  also  in  small  quantity 
free  and  as  chlorid. 

Preparation. — The  commercial  product  is  usually  obtained  by 
simple  distillation  in  a  current  of  air:  HgS+O2=Hg+SO2.  If  re- 
quired pure,  it  must  be  freed  from  other  metals  by  distillation,  and 
agitation  of  the  redistilled  product  with  mercurous  nitrate  solution, 
solution  of  Fe2Cl6,  or  dilute  HNO3. 

Properties. — Physical. — A  bright  metallic  liquid  ;  volatile  at  all 
temperatures.  Crystallizes  in  octahedra  of  sp.  gr.  14.0.  When  pure, 
it  rolls  over  a  smooth  surface  in  round  drops.  The  formation  of  tear- 
shaped  drops  indicates  the  presence  of  impurities. 

Chemical. — If  pure,  it  is  not  altered  by  air  at  the  ordinary  tem- 
perature, but,  if  contaminated  with  foreign  metals,  its  surface  be- 
comes dimmed.  Heated  in  air,  it  is  oxidized  superficially  to  HgO.  It 


MEECURY  209 

does  not  decompose  H2O.  It  combines  directly  with  Cl,  Br,  I,  and  S. 
It  alloys  readily  with  most  metals  to  form  amalgams.  It  amalga- 
mates with  Fe  and  Pt  only  with  difficulty.  Hot,  concentrated,  H2SO4 
dissolves  it,  with  evolution  of  862,  and  formation  of  HgSO-t.  It  dis- 
solves in  cold  HNOs,  with  formation  of  a  nitrate. 

Elementary  mercury  is  insoluble  in  H^O,  and  probably  in  the 
digestive  liquids.  It  enters,  however,  into  the  formation  of  three 
medicinal  agents:  hydrargyrum  cum  creta  (U.  S.;  Br.);  massa  hy- 
drargyri  (U.  S.)— pilula  hydrargyri  (Br.);  and  unguentum  hydrar- 
gyri  (U.  S.;  Br.),  all  of  which  owe  their  efficacy,  not  to  the  metal 
itself,  but  to  a  certain  proportion  of  oxid,  produced  during  their 
manufacture.  The  fact  that  blue  mass  is  more  active  than  mercury 
with  chalk  is  due  to  the  greater  proportion  of  oxid  contained  in  the 
former.  It  is  also  probable  that  absorption  of  vapor  of  Hg  by  cuta- 
neous surfaces  is  attended  by  its  conversion  into  HgCb. 

Oxids. — Mercurous  Oxid — Protoxid  or  black  oxid  of  mercury — 
(Hgo)O — 416.6 — is  obtained  by  adding  a  solution  of  (Hg2)(NOs)2  to 
an  excess  of  solution  of  KHO.  It  is  a  brownish  black,  tasteless 
powder;  very  prone  to  decomposition  into  HgO  and  Hg.  It  is  con- 
verted into  (Hg2)Cla  by  HC1;  and  by  other  acids  into  the  corre- 
sponding mercurous  salts. 

It  is  formed  by  the  action  of  CaH2(>2  on  mercurous  compounds, 
and  exists  in  black  wash. 

Mercuric  Oxid  —  Red,  or  binoxid  of  mercury  —  Hydrargyri  oxi- 
dum  flavum  (U.  S.;  Br.) — Hydrargyri  oxidum  rubrum  (U.  S.;  Br.) 
HgO — 216.3  —  is  prepared  by  two  methods:  (1)  by  calcining  Hg- 
(NOsh,  as  long  as  brown  fumes  are  given  off  (Hydr.  oxid.  rubr.): 
or,  (2)  by  precipitating  a  solution  of  a  mercuric  salt  by  excess  of 
KHO  (Hydr.  oxid.  flavum).  The  products  obtained,  although  the 
same  in  composition,  differ  in  physical  characters  and  in  the  activity 
of  their  chemical  actions.  That  obtained  by  (1)  is  red  and  crystalline; 
that  obtained  by  (2)  is  yellow  and  amorphous.  The  latter  is  much 
the  more  active  in  its  chemical  and  medicinal  actions. 

It  is  very  sparingly  soluble  in  H2O,  the  solution  having  an  alka- 
line reaction,  and  a  metallic  taste.  It  exists  both  in  solution  and 
in  suspension  in  yellow  wash,  prepared  by  the  action  of  CaH2O2 
on  a  mercuric  compound. 

Exposed  to  light  and  air,  it  turns  black,  more  rapidly  in  presence 
of  organic  matter,  giving  off  O,  and  liberating  Hg:HgO  =  Hg  +  O. 
It.  decomposes  the  chlorids  of  many  metallic  elements  in  solution, 
with  formation  of  a  metallic  oxid  and  mercuric  oxychlorids.  It 
combines  with  alkaline  chlorids  to  form  soluble  double  chlorids, 
called  chloromercurates  or  chlorhydrargy rates ;  and  forms  similar 
compounds  with  alkaline  iodids  and  bromids. 
14 


210  MANUAL    OF    CHEMISTRY 

Sulfids.— Mercurous  Sulfid — (Hg2)  S — 432.6  —  a  very  unstable 
compound,  formed  by  the  action  of  IbS  on  mercurous  salts. 

Mercuric  Sulfid  —  Red  sulfid  of  mercury  —  Cinnabar — Vermil- 
ion —  Hydrargyri  sulfidum  rubrum  (U.  S.)— HgS  —  232,3—  exists 
in  nature  in  amorphous  red  masses,  or  in  red  crystals,  and  is  the 
chief  ore  of  Hg.  If  Hg  and  S  be  ground  up  together  in  the  cold, 
or  if  a  solution  of  a  mercuric  salt  be  completely  decomposed  by 
H2S,  a  black  sulfid  is  obtained,  which  is  the  -dEthiops  mineralis  of 
the  older  pharmacists. 

A  red  sulfid  is  obtained  for  use  as  a  pigment  (vermilion),  by 
agitating  for  some  hours  at  60°  (140°  F.)  a  mixture  of  Hg,  S,  KHO, 
and  EkO.  It  is  a  fine,  red  powder,  which  turns  brown,  and  finally 
black,  when  heated.  Heated  in  air,  it  burns  to  862  and  Hg.  It 
is  decomposed  by  strong  H2SO4,  but  not  by  HNOs  or  HC1. 

Chlorids. —  Mercurous  Chlorid — Protochlorid  or  mild  cJilorid  of 
mercury  —  Calomel — Hydrargyri  chloridum  mite  (U.  S.) — Hydrar- 
gyri subchloridum  (Br.)  —  (Hg2)Cl2 — 471.5  —  is  now  principally 
obtained  by  mutual  decomposition  of  NaCl  and  (Hg2)S(>4.  Mer- 
curic sulfate  is  first  obtained  by  heating  together  2  pts.  Hg  and 
3  pts.  H2SO4;  the  product  is  then  caused  to  combine  with  a  quantity 
of  Hg  equal  to  that  first  used,  to  form  (Hg2)S(>4;  which  is  then  mixed 
with  dry  NaCl,  and  the  mixture  heated  in  glass  vessels,  connected  with 
condensing  chambers;  2NaCl  +  (Hg2)SO4  =  Na2SO4 +  (Hg2)Cl2. 

In  practice,  varying  quantities  of  HgCl2  are  also  formed,  and 
must  be  removed  from  the  product  by  washing  with  boiled,  distilled 
H2O,  until  the  washings  no  longer  precipitate  with  NHtHO.  The 
presence  of  HgCl2  in  calomel  may  be  detected  by  the  formation  of  a 
black  stain  upon  a  bright  copper  surface,  immersed  in  the  calomel, 
moistened  with  alcohol;  or  by  the  production  of  a  black  color  by  H2S 
in  H2O  which  has  been  in  contact  with  and  filtered  from  calomel  so 
contaminated. 

Calomel  is  also  formed  in  a  number  of  other  reactions:  (1)  By  the 
action  of  Cl  upon  excess  of  Hg.  (2)  By  the  action  of  Hg  upon 
Fe2Cl6.  (3)  By  the  action  of  HC1,  or  of  a  chlorid,  upon  (Hg2)O,  or 
upon  a  mercurous  salt.  (2)  By  the  action  of  reducing  agents,  in- 
cluding Hg,  upon  HgCh. 

Calomel  crystallizes  in  nature,  and,  when  sublimed,  in  quadratic 
prisms.  When  precipitated  it  is  deposited  as  a  heavy,  amorphous, 
white  powder,  faintly  yellowish,  and  producing  a  yellowish  mark  when 
rubbed  upon  a  dark  surface.  It  sublimes,  without  fusing,  between 
420°  and  500°  (788°-932°  F.),  is  insoluble  in  cold  H2O  and  in  alco- 
hol; soluble  in  boiling  H2O  to  the  extent  of  1  part  in  12,000.  When 
boiled  with  H2O  for  some  time,  it  suffers  partial  decomposition,  Hg  is 
deposited  and  HgCl2  dissolves. 


MERCURY  211 

Although  Hg2Cl2  is  insoluble  in  IbO,  in  dilute  HC1  and  in  pepsin 
solution,  it  is  dissolved  at  the  body  temperature  in  an  aqueous  solu- 
tion of  pepsin  acidulated  with  HC1. 

When  exposed  to  light,  calomel  becomes  yellow,  then  gray,  owing 
to  partial  decomposition,  with  liberation  of  Hg  and  formation  of 
HgCl2:  (Hg2)Cl2:=Hg-}-HgCl2.  It  is  converted  into  HgCl2  by  Cl  or 
aqua  regia:  (Hg2)Cl2+Cl2=2HgCl2.  In  the  presence  of  EbO,  I  con- 
verts it  into  a  mixture  of  HgCl2  and  Hgl2:  (Hg2)Cl2+l2=HgCl2+ 
Hgl2.  It  is  also  converted  into  HgCb  by  HC1  and  by  alkaline  chlor- 
ids:  (Hg2)Cl2=HgCl2+Hg.  This  change  occurs  in  the  stomach  when 
calomel  is  taken  internally,  and  that  to  such  an  extent  when  large 
quantities  of  NaCl  are  taken  with  the  food,  that  calomel  cannot  be  used 
in  naval  practice  as  it  may  be  with  patients  who  do  not  subsist  upon 
salt  provisions.  It  is  converted  by  KI  into  (Hg2)l2:  (Hg2)Cl2+2KI 
=2KClH-(Hg2)l2;  which  is  then  decomposed  by  excess  of  KI  into 
Hg  and  Hgl2,  the  latter  dissolving:  (Hg2)l2=Hg-fHgl2.  Solutions 
of  the  sulfates  of  Na,  K  and  NH4  dissolve  notable  quantities  of 
(Hg2)Cl2.  The  hydroxids  and  carbonates  of  K  and  Na  decompose  it 
with  formation  of  (Hg2)O:  (Hg2)Cl2  +  Na2CO3  =  (Hg2)OH- CO2+ 
2NaCl;  and  the  (Hg2)O  so  formed  is  decomposed  into  HgO  and  Hg. 
If  alkaline  chlorids  be  also  present,  they  react  upon  the  HgO  so  pro- 
duced, with  formation  of  HgCl2. 

Mercuric  Chlorid — Perchlorid  or  bichlorid  of  mercury — Corrosive 
sublimate— Hydrargyri  chloridum  corrosivum  (U.  S.);  Hydrargyri 
perchloridum  (Br.) — HgCl2 — 271.2 — is  prepared  by  heating  a  mixture 
of  5  pts.  dry  HgSO*  with  5  pts.  dry  NaCl,  and  1  pt.  MnO2  in  a  glass 
vessel  communicating  with  a  condensing  chamber. 

It  crystallizes  by  sublimation  in  octahedra,  and  by  evaporation  of 
its  solutions  in  flattened,  right  rhombic  prisms;  fuses  at  265°  (509° 
F.),  and  boils  at  about  295°  (563°  F.);  soluble  in  H2O  and  in 
alcohol;  very  soluble  in  hot  HC1,  the  solution  gelatinizing  on  cooling. 
Its  solutions  have  a  disagreeable,  acid,  styptic  taste,  and  are  highly 
poisonous.  Although  HgCl2  is  heavier  than  water  (sp.  gr.=5.4) 
when  the  crystalline  powder  is  thrown  upon  water  a  portion  floats 
for  some  time. 

It  is  easily  reduced  to(Hg2)Cl2  and  Hg,  and  its  aqueous  solutions 
are  so  decomposed  when  exposed  to  light;  a  change  which  is  retarded 
by  the  presence  of  NaCl.  Heated  with  Hg,  it  is  converted  into 
(Hg2)Cl2.  When  dry  HgCh,  or  its  solution,  is  heated  with  Zn,  Cd, 
Ni,  Fe,  Pb,  Cu,  or  Bi,  those  elements  remove  part  or  all  of  its  Cl, 
with  separation  of  (Hg2)Cl2  or  Hg.  Its  solution  is  decomposed  by 
H2S,  with  separation  of  a  yellow  sulfochlorid,  which,  with  an  excess 
of  the  gas,  is  converted  into  black  HgS.  It  is  soluble  without  de- 
composition in  H2SO4,  HNOs,  and  HC1.  It  is  decomposed  by  KHO  or 


212  MANUAL    OF    CHEMISTRY 

NallO,  with  separation  of  a  brown  oxychlorid  if  the  alkaline 
hydroxid  be  in  limited  quantity;  or  of  the  orange -colored  HgO  if  it 
be  in  excess.  A  similar  decomposition  is  effected  by  CaH2O2  and 
HgH2O2;  which  does  not,  however,  take  place  in  presence  of  an 
alkaline  chlorid,  or  of  certain  organic  matters,  such  as  sugar  and 
gum.  Many  organic  substances  decompose  it  into  (Hg2)Cl2  or  Hg, 
especially  under  the  influence  of  sunlight.  Thus  in  sunlight  it  is 
reduced  by  oxalic  acid,  which  is  itself  oxidized  to  carbon  dioxid: 
2HgCl2+C2O4H2=Hg2Cl2-f-2C02+2HCl.  For  this  reason  it  behaves 
as  an~oxidarit:  2HgCl2+H2O— Hg2Cl2+2HCl+O.  Albumen  forms 
with  it  a  white  precipitate,  which  is  insoluble  in  H2O,  but  soluble  in 
an  excess  of  fluid  albumen  and  in  solutions  of  alkaline  chlorids.  It 
readily  combines  with  metallic  chlorids,  to  form  soluble  double 
chlorids,  called  chloromercurates  or  chlorhydrargyrates.  One  of 
these,  obtained  in  flattened,  rhombic  prisms,  by  the  cooling  of  a  boil- 
ing solution  of  Hg012  and  NEUCl,  has  the  composition  Hg(NHt)2- 
Cl2+Aq,  and  was  formerly  known  as  sal  alembroth  or  sal  sapientice . 
It  is  a  very  energetic  germicide. 

Mercurammonium  Chlorid — Mercury  chloramidid — Infusible  white 
precipitate — Ammoniated  mercury  —  Hydrargyrum  ammoniatum  (U. 
S.;  Br.) — NH2HgCl — 251.8 — is  prepared  by  adding  a  slight  excess  of 
NEUHO  to  a  solution  of  HgCl2.  It  is  a  white  powder,  insoluble  in 
alcohol,  ether,  and  cold  H2O:  decomposed  by  hot  H2O,  with  separa- 
tion of  a  heavy,  yellow  powder.  It  is  entirely  volatile,  without 
fusion.  The  fusible  white  precipitate  is  formed  in  small  crystals  when 
a  solution  containing  equal  parts  of  HgCl2  and  NEUCl  is  decomposed 
by  Na2COs.  It  is  mercurdiammonium  chlorid,  NH2Hg,NH4Cl2. 

lodids. —  Mercurous  lodid — Protoiodid  or  yelloiv  iodid  —  Hydrar- 
gyri  iodidum  viride  (U.  S.;  Br.) — Hg2l2 — 654.3  —  is  prepared  by 
grinding  together  200  pts.  Hg  and  127  pts.  I  with  a  little  alcohol, 
until  a  green  paste  is  formed.  It  is  a  greenish -yellow,  amorphous 
powder,  insoluble  in  H2O  and  in  alcohol.  When  heated,  it  turns 
brown,  and  volatilizes  completely.  When  exposed  to  light,  or  even 
after  a  time  in  the  dark,  it  is  decomposed  into  HgI2  and  Hg.  The 
same  decomposition  is  brought  about  instantly  by  KI;  more  slowly 
by  solutions  of  alkaline  chlorids,  and  by  HC1  when  heated.  NH4HO 
dissolves  it  with  separation  of  a  gray  precipitate. 

Mercuric  Iodid — Biniodid  or  red  iodid — Hydrargyri  iodidum  ru- 
brum  (U.  S.;  Br.) — Hgl2 — 454 — is  obtained  by  double  decomposition 
between  H£C12  and  KI,  care  being  had  to  avoid  too  great  an  excess  of 
the  alkaline  iodid,  that  the  soluble  potassium  iodhydrargyrate  may 
not  be  formed. 

It  is  sparingly  soluble  in  H2O ;  but  forms  colorless  solutions  with 
alcohol.  It  dissolves  readily  in  many  dilute  acids,  and  in  solutions  of 


MERCURY  213 

ammoniacal  salts,  alkaline  chlorids,  and  mercuric  salts;  and  in  solu- 
tions of  alkaline  iodids.  Iron  and  copper  convert  it  into  (Hg2)l2, 
then  into  Hg.  The  hydroxids  of  K  and  Na  decompose  it  into  oxid  or 
oxyiodid,  and  combine  with  another  portion  to  form  iodhydrargyrates, 
which  dissolve.  NUtHO  separates  from  its  solution  a  brown  powder, 
and  forms  a  yellow  solution,  which  deposits  white  flocks. 

Mercuric  Cyanid  —  Hydrargyri  cyanidum  (U.  S.) — HgCCNh — 
252.3 — is  best  prepared  by  heating  together,  for  a  quarter  of  an  hour, 
potassium  ferrocyanid,  1  pt.;  HgSO*,  2  pts.;  and  H2O,  8  pts.  It 
crystallizes  in  quadrangular  prisms;  soluble  in  8  pts.  of  EkO,  much 
less  soluble  in  alcohol ;  highly  poisonous.  When  heated  dry  it 
blackens,  and  is  decomposed  into  (CN)2  and  Hg;  if  heated  in  pres- 
ence of  IbO  it  yields  HCN,  Hg,  €62,  and  NHs.  Hot  concentrated 
H2SO4,  and  HOI,  HBr,  HI,  and  H2$>in  the  cold  decompose  it,  with 
liberation  of  HCN.  It  is  not  decomposed  by  alkalies- 
Nitrates. — There  exist,  besides  the  normal  nitrates:  (Hg2)  (NOah, 
and  Hg(NO3)2,  three  basic  mercurous  nitrates,  three  basic  mercuric 
nitrates,  and  a  mercuroso- mercuric  nitrate. 

Mercurous  Nitrate— (Hg2)  (NO3 ) 2+2 Aq— 524.6+36— is  formed 
when  excess  of  Hg  is  digested  with  HNOs,  diluted  with  %  vol.  H2O; 
until  short,  prismatic  crystals  separate. 

It  effloresces  in  air;  fuses  at  70°  (158°  F.);  dissolves  in  a  small 
quantity  of  hot  H2O,  but  with  a  larger  quantity  is  decomposed  with 
separation  of  the  yellow,  basic  trimercuric  nitrate  Hg(NO3)2,2HgO+ 
Aq. 

Dimercurous  Nitrate  —  (Hg2)  (NO3) 2,  Hg2O+Aq—  941.2+18  —  is 
formed  by  acting  upon  the  preceding  salt  with  cold  H2O  until  it  turns 
lemon -yellow;  or  by  extracting  with  cold  H2<3  the  residue  of  evapo- 
ration of  the  product  obtained  by  acting  upon  excess  of  Hg  with  con- 
centrated HN03. 

Trimercurous  Nitrate  — (Hg2)2(N03)4,  Hg2O+3Aq— 1465.8+54 
—is  obtained  in  large,  rhombic  prisms,  when  excess  of  Hg  is  boiled 
with  HNOa,  diluted  with  5  pts.  H2O,  for  5-6  hours,  the  loss  by  evap- 
oration being  made  up  from  time  to  time. 

Mercuric  Nitrate— Hg(NO3)2— 324.3— is  formed  when  Hg  or  HgO 
is  dissolved  in  excess  of  HNOs,  and  the  solution  evaporated  at  a 
gentle  heat.  A  syrupy  liquid  is  obtained,  which,  over  quicklime,  de- 
posits large,  deliquescent  crystals,  having  the  composition  2[Hg- 
(NOsJal+Aq,  while  there  remains  an  uncrystallizable  liquid,  Hg- 
(NO3)2+2Aq. 

This  salt  is  soluble  in  H2O,  and  exists  in  the  Liq.  hydrargyri  ni- 
tratis  (U.  S.),  Liq.  hydrargyri  nitratis  acidus  (Br.);  in  the  volu- 
metric standard  solution  used  in  Liebig's  process  for  uren ;  and  prob- 
ably in  citrine  ointment=Ung.  hydrar.  nitratis  (U.  S.;  Br.). 


214  MANUAL    OF    CHEMISTRY 

Dimercurie  Nitrate  —  Hg(NO3) 2,  HgO+Aq— 540.6  — is  formed 
when  HgO  is  dissolved  to  saturation  in  hot  HNO3,  diluted  with  1  vol. 
H20;  and  crystallizes  on  cooling.  It  is  decomposed  by  H2O  into 
trimercuric  nitrate,  Hg(N03)2,  2HgO,  and  Hg(NO3)2. 

Hexamercuric  Nitrate— Hg(NO3)2,  5HgO— 1405.8— is  formed  as 
a  red  powder,  by  the  action  of  H2O  on  trimercuric  nitrate. 

Sulfates. — Mercurous  Sulfate — (Hg2)SC>4 — 495.4 — is  a  white, 
crystalline  powder,  formed  by  gently  heating  together  2  pts.  Hg  and 
3  pts.  H2SO4,  and  causing  the  product  to  combine  with  2  pts.  Hg. 
Heated  with  NaCl  it  forms  (Hg2)Cl2. 

Mercuric  Sulfate— Hydrargyri  sulfas  (Br.)—HgSO4— 296.3 — is 
obtained  by  heating  together  Hg  and  H2SO4,  or  Hg,  H2SO4,  and 
HNO3.  It  is  a  white,  crystalline,  anhydrous  powder,  which,  on  con- 
tact with  H2O,  is  decomposed  with  formation  of  trimercuric  sulfate, 
HgSOi,  2HgO;  a  yellow,  insoluble  powder,  known  as  turpeth  min- 
eral^ Hydrargyri  subsulfas  flavus  (U.  S.). 

Analytical  Characters.  —  MERCUROUS. — (1)  Hydrochloric  acid: 
white  ppt.;  insoluble  in  H2O  and  in  acids;  turns  black  with  NH4HO; 
when  boiled  with  HC1,  deposits  Hg,  while  HgCl2  dissolves.  (2)  Hy- 
drogen sulfid:  black  ppt.;  insoluble  in  alkaline  sulf hydrates,  in  dilute 
acids,  and  in  KCN;  partly  soluble  in  boiling  HNO3.  (3)  Potash: 
black  ppt.;  insoluble  in  excess.  (4)  Potassium  iodid:  greenish  ppt.; 
converted  by  excess  into  Hg,  which  is  deposited,  and  HgI2,  which  dis- 
solves. 

MERCURIC.— (1)  Hydrogen  sulfid:  black  ppt.  If  the  reagent  be 
slowly  added,  the  ppt.  is  first  white,  then  orange,  finally  black.  (2) 
Ammonium  sulfhydrate:  black  ppt.;  insoluble  in  excess,  except  in 
the  presence  of  organic  matter.  (3)  Potash  or  soda:  yellow  ppt.; 
insoluble  in  excess.  (4)  Ammonium  hydroxid:  white  ppt.;  soluble  in 
great  excess  and  in  solutions  of  NH4  salts.  (5)  Potassium  carbonate: 
red  ppt.  (6)  Potassium  iodid  :  yellow  ppt.,  rapidly  turning  to  sal- 
mon color,  then  to  red;  easily  soluble  in  excess  of  KI,  or  in  great 
excess  of  mercuric  salt.  (7)  Stannous  chlorid,  in  small  quantity: 
white  ppt.;  in  larger  quantity:  gray  ppt.;  and  when  boiled:  deposit  of 
globules  of  Hg. 

Action  on  the  Economy. — Mercury,  in  the  metallic  form,  is  with- 
out action  upon  the  animal  economy  so  long:  as  it  remains  such.  On 
contact,  however,  with  alkaline  chlorids  it  is  converted  into  a  soluble 
double  chlorid,  and  this  the  more  readily  the  greater  the  degree  of 
subdivision  of  the  metal.  The  mercurials  insoluble  in  dilute  HC1  are 
also  inert  until  they  are  converted  into  soluble  compounds. 

Mercuric  chlorid,  a  substance  into  which  many  other  compounds 
of  Hg  are  converted  when  taken  into  the  stomach  or  applied  to  the 
skin,  not  only  has  a  distinctly  corrosive  action,  by  virtue  of  its  ten- 


MEECUEY  215 

dency  to  unite  with  protein  bodies,  but,  when  absorbed,  it  produces 
well-marked  poisonous  effects,  somewhat  similar  to  those  of  arsenical 
poisoning.  Indeed,  owing  to  its  corrosive  action,  and  to  its  greater 
solubility  and  more  rapid  absorption,  it  is  a  more  dangerous  poison 
than  As2Oa.  In  poisoning  by  HgCh,  the  symptoms  begin  sooner 
after  the  ingestion  of  the  poison  than  in  arsenical  poisoning,  and 
those  phenomena  referable  to  the  local  action  of  the  toxic  are  more 
intense.  But  the  entire  duration  of  the  poisoning  is  greater,  In  fatal 
cases,  death  usually  occurs  in  5  to  12  days. 

The  treatment  should  consist  in  the  administration  of  white  of 
egg,  not  in  too  great  quantity,  and  the  removal  of  the  compound 
formed,  by  emesis,  before  it  has  had  time  to  redissolve  in  the  alkaline 
chlorids  contained  in  the  stomach. 

Absorbed  Hg  tends  to  remain  in  the  system  in  combination  with 
protein  bodies,  from  which  it  may  be  set  free,  or,  more  properly, 
brought  into  soluble  combination,  at  a  period  quite  removed  from  the 
date  of  last  administration,  by  the  exhibition  of  alkaline  iodids. 

Mercury  is  eliminated  principally  by  the  saliva  and  urine,  in  which 
it  may  be  readily  detected.  The  fluid  is  faintly  acidulated  with  HC1, 
and  in  it  is  immersed  a  short  bar  of  Zn,  around  which  a  spiral  of 
dentist's  gold  foil  is  wound  in  such  a  way  as  to  expose  alternate  sur- 
faces of  Zn  and  Au.  After  24  hours,  if  the  saliva  or  urine  contain 
Hg,  the  Au  will  be  whitened  by  amalgamation;  and,  if  dried  and 
heated  in  the  closed  end  of  a  small  glass  tube,  will  give  off  Hg,  which 
condenses  in  globules,  visible  with  the  aid  of  a  magnifier,  in  the  cold 
part  of  the  tube. 


216  MANUAL    OF    CHEMISTRY 

ORGANIC    CHEMISTEY. 
COMPOUNDS  OF  CARBON. 

In  the  beginning  of  the  present  century  chemistry  was  divided 
into  the  two  sections  of  inorganic  and  organic.  The  former  treated 
of  the  products  of  the  mineral  world,  the  latter  of  substances  produced 
in  organized  bodies,  vegetable  or  animal.  This  subdivision,  originally 
made  upon  the  supposition  that  organic  substances  could  only  be  pro- 
duced by  "vital  processes,"  is  retained  only  for  convenience  and  be- 
cause of  the  great  number  of  the  carbon  compounds. 

When  it  was  found  that  organic  substances  were  made  up  of  a 
very  few  elements,  and  that  they  all  contained  carbon,  Gmelin  pro- 
posed to  consider  as  organic  substances  all  such  as  contained  more 
than  one  atom  of  C,  his  object  in  thus  limiting  the  minimum  number 
of  C  atoms  being  that  substances  containing  one  atom  of  C,  such  as 
carbon  dioxid  and  marsh  gas,  are  formed  in  the  mineral  kingdom, 
and  consequently,  according  to  then  existing  views,  could  not  be  con- 
sidered as  organic.  Such  a  distinction,  still  adhered  to  in  text -books 
of  very  recent  date,  of  necessity  leads  to  most  incongruous  results. 
Under  it  the  first  terms  of  the  homologous  series  (see  p.  218)  of  satu- 
rated hydrocarbons,  CELt,  alcohols,  CELiO,  acids,  CH2O2,  and  all  their 
derivatives  are  classed  among  mineral  substances,  while  all  the  higher 
terms  of  the  same  series  are  organic.  Under  it  urea,  CON2H4,  the 
chief  product  of  excretion  of  the  animal  body,  is  a  mineral  substance, 
but  ethene,  C2H4,  obtained  from  the  distillation  of  coal,  is  organic. 

The  idea  of  organic  chemistry  conveyed  by  the  definition:  "that 
branch  of  the  science  of  chemistry  which  treats  of  the  carbon  com- 
pounds containing  hydrogen,"  is  still  more  fantastic.  Under  it  hy- 
drocyanic acid,  CNH,  is  "organic,"  but  the  cyanids,  CNK,  are 
"mineral."  Oxalic  acid,  C204H2,  is  "organic,"  and  potassium  hy- 
droxid,  KHO,  unquestionably  "mineral."  If  these  two  act  upon 
each  other  in  the  proportion  of  90  parts  of  the  former  to  56  of  the 
latter,  the  "organic"  monopotassic  oxalate,  C2O4HK,  is  formed,  but 
if  the  proportion  of  KHO  be  doubled,  other  conditions  remaining  the 
same,  the  "mineral"  dipotassic  oxalate,  C2O4K2,  is  produced.  Simi- 
larly one  of  the  sodium  carbonates,  Na^COa,  is  "mineral;"  the  other, 
NaHCO3,  is  "organic." 

The  notion  that  organic  substances  could  only  be  formed  by  some 
mysterious  agency,  manifested  only  in  organized  beings,  was  finally 
exploded  by  the  labors  of  Wohler  and  Kolbe.  The  former  obtained 
urea  from  ammonium  cyanate  (1828);  while  the  latter,  at  a  subse- 


COMPOUNDS    OF    CARBON  217 

quent  period,  formed  acetic  acid,  using  in  its  preparation  only  such 
unmistakably  mineral  substances  as  coal,  sulfur,  aqua  regia,  and 
water.  Since  Wohler's  first  synthesis,  chemists  have  succeeded  not 
only  in  making  from  mineral  materials  many  of  the  substances  pre- 
viously only  formed  in  the  laboratory  of  nature,  but  have  also  pro- 
duced a  vast  number  of  carbon  compounds  which  were  previously 
unknown,  and  which,  so  far  as  we  know,  have  no  existence  in 
nature. 

At  the  present  time,  therefore,  we  must  consider  as  an  organic 
substance  any  compound  containing  carbon,  whatever  may  be  its 
origin  and  whatever  its  properties. 

Organic  chemistry  is,  therefore,  simply  the  chemistry  of  the  car- 
bon compounds.  In  the  study  of  the  compounds  of  the  other  ele- 
ments, we  have  to  deal  with  a  small  number  of  substances,  relatively 
speaking,  formed  by  the  union  with  each  other  of  a  large  number  of 
elements.  With  the  organic  substances  the  reverse  is  the  case. 
Although  compounds  have  been  formed  which  contain  C  along  with 
each  of  the  other  elements,  the  great  majority  of  the  organic  sub- 
stances are  made  up  of  C,  combined  with  a  very  few  other  elements; 
H,  O,  and  N  occurring  in  them  most  frequently. 

It  is  chiefly  in  the  study  of  the  carbon  compounds  that  we  have  to 
deal  with  radicals  (see  p.  52).  Among  mineral  substances  there 
are  many  whose  molecules  consist  simply  of  a  combination  of  two 
atoms.  Among  organic  substances  there  is  none  which  does  not 
contain  a  radical:  indeed,  organic  chemistry  has  been  defined  as  "the 
chemistry  of  compound  radicals." 

The  atoms  of  carbon  possess  in  a  higher  degree  than  those  of  any 
other  element  the  power  of  uniting  with  each  other,  and  in  so  doing 
of  interchanging  valences.  Were  it  not  for  this  property  of  the  C 
atoms,  we  could  have  but  one  saturated  compound  of  carbon  and 
hydrogen,  CH4,  or  expressed  graphically: 

H 


H— C— H 


There  exist,  however,  a  great  number  of  such  compounds,  which 
differ  from  each  other  by  one  atom  of  C  and  two  atoms  of  H.  In 
these  substances  the  atoms  of  C  may  be  considered  as  linked  together 
in  a  continuous  chain,  their  free  valences  being  satisfied  by  H  atoms, 
thus: 

H  H   H  H   H   H    H 

I  II  till 

H— C— C— C— C— H 


H— C— H  H— C— C— H 

I  I      I 

H  H   H  H   H 


I  II  I      I      I      I 

H    H 


218 


MANUAL    OF    CHEMISTRY 


Homologous  Series.— It  will  be  observed  that  these  formulae 
differ  from  each  other  by  CE.2,  or  some  multiple  of  CH2,  more  or  less. 
In  examining  numbers  of  organic  substances  which  are  closely  related 
to  each  other  in  their  properties,  we  find  that  we  can  arrange  the 
great  majority  of  them  in  series,  each  term  of  which  differs  from  the 
one  below  it  by  CH2;  such  a  series  is  called  an  homologous  series. 
It  will  be  readily  understood  that  such  an  arrangement  in  series  vastly 
facilitates  the  remembering  of  the  composition  of  organic  bodies.  In 
the  following  table,  for  example,  are  given  the  saturated  hydrocar- 
bons, and  their  more  immediate  derivatives.  At  the  head  of  each 
vertical  column  is  an  algebraic  formula,  which  is  the  general  formula 
of  the  entire  series  below  it;  n  being  eq'ual  to  the  numerical  position 
in  the  series. 

HOMOLOGOUS   SERIES. 


Saturated  hy- 
drocarbons, 
CnH2»+2 

Alcohols, 
CnH2W+2O 

Aldehydes 
C»H2«O 

Acids, 
C»H2«O2 

Ketones, 

CH4 

CH40 

CH2O 

CO2H2 

C2H60 

C2H4O 

C202H4 

C3H8 

C3H80 

C3H60 

C302H6 

C3H6O 

C4H10O 

C4H8O 

C402H8 

C4H8O 

Csfi!" 

C5Hi2O 

C5HioO 

C502H10 

C5HioO 

C6H140 

C6H120 

C602H12 

C7H!e 

C7H160 

C7Hi40 

CT^O^H^ 

C8H18 

C8H180 

C8Hi6O 

C8O2Hie 

C9H2o 

C9H200 

CgO2Hi8 

CioH22 

Ci0H220 

CioO2H2o 

clilE 

.... 

Ci2O2H24 

C;*H- 

.... 

CuO2H28 

But  the  arrangement  in  homologous  series  does  more  for  us  than 
this.  The  properties  of  substances  in  the  same  series  are  similar,  or 
vary  in  regular  gradation  according  to  their  position  in  the  series. 
Thus,  in  the  series  of  monoatomic  alcohols  (see  above)  each  member 
yields  on  oxidation,  first  an  aldehyde,  then  an  acid.  Each  yields  a 
series  of  compound  ethers  by  the  action  of  acids  upon  it.  The  boil- 
ing-points of  ethylic  alcohol  and  its  seven  superior  homologues  are: 
78.3°,  97.4°,  116.8°  137°,  157°,  176°,  195°,  from  which  it  will  be 
seen  that  the  boiling-point  of  any  one  of  them  can  be  determined, 
with  a  maximum  error  of  less  than  1°,  by  taking  the  mean  of  those 
of  its  neighbors  above  and  below.  In  this  way  we  may  predict,  to 
some  extent,  the  properties  of  a  wanting  member  in  a  series  before  its 
discovery. 

The  terms  of  any  homologous  series  must  all  have  the  same  con- 


COMPOUNDS    OP    CAEBON  219 

stitution,  i.  e.,  their  constituent  atoms  must  be  similarly  arranged 
within  the  molecule.     (See  p.  53.) 

Isomerism — Metamerism — Polymerism. — Two  substances  are 
said  to  be  isomeric,  or  to  be  isomeres  of  each  other,  when  they 
have  the  same  centesimal  composition.  If,  for  instance,  we  ana- 
lyze acetic  acid,  formic  aldehyde  and  methyl  formate,  we  find  that 
each  body  consists  of  C,  O  and  H,  in  the  following  proportions: 

Carbon 40          =12 

Oxygen 53.33     =     16 

Hydrogen 6.67    =       2 


100.00  30 

This  identity  of  percentage  composition  may  occur  in  two  ways. 
The  three  substances  may  each  contain  the  same  number  of  each  kind 
of  atom  in  a  molecule;  or  they  may  contain  in  their  several  molecules 
the  same  kinds  of  atoms  in  multiple  proportions.  In  the  above  ex- 
ample each  substance  may  have  the  formula,  CH2O;  or  one  may  have 
that  formula  and  the  others  C2H4O2,  C3H6O3,  C4H8O4,  C5Hio05,  etc. 

When  two  or  more  substances  have  the  same  percentage  com- 
position and  the  same  molecular  weight  they  are  said  to  be  meta- 
meric.  When  they  have  the  same  percentage  composition  and  their 
molecular  weights  are  simple  multiples  of  the  lowest  molecular 
weight  represented  by  that  percentage  composition,  they  are  said 
to  be  polymeric. 

Other  conditions  of  isomerism  will  be  considered  later  (see  space 
isomerism,  p.  266,  and  place  isomerism,  pp.  290,  381). 

In  order  to  determine  the  composition  (the  empirical  formula)  of 
an  organic  substance,  two  factors  are  therefore  necessary  :  the  per- 
centage composition  and  the  molecular  weight. 

Elementary  Organic  Analysis. — The  first  step  in  an  analysis  to 
determine  the  composition  of  an  organic  substance  is  a  qualitative 
analysis  to  identify  the  elements  existing  in  the  molecule.  This 
having  been  done,  the  quantitative  analysis  is  next  in  order. 

The  simplest  case  is  where  the  substance  is  a  hydrocarbon,  i.  e., 
a  compound  of  carbon  and  hydrogen  only.  The  determination  of 
both  elements  is  made  in  one  operation,  by  taking  advantage  of  the 
fact  that  when  a  compound  containing  carbon  and  hydrogen  is  heated 
with  cupric  oxid  all  the  carbon  is  converted  into  CO2,  and  all  the 
hydrogen  into  H2O.  Thus,  if  C2H6O+6CuO=2CO2+3H2O+6Cu,  46 
parts  of  alcohol  will  produce  88  pts.  of  carbon  dioxid  and  54  pts.  of 
water.  The  apparatus  required  consists  of  a  tube  of  difficultly  fusible 
glass,  called  a  combustion  tube,  about  60  cent,  long,  drawn  out  to  a 
point  and  closed  at  one  end,  a  "combustion  furnace,"  in  which  this 
tube  may  be  heated,  and  the  absorbing  apparatus  referred  to  below. 


220 


MANUAL    OP    CHEMISTRY 


A  weighed  quantity  of  the  substance  of  which  a  "  combustion  "  is  to  be 
made  (sealed  in  a  small  glass  bulb  if  liquid)  is  placed  in  the  closed 
end  of  the  combustion  tube,  a  Fig.  32,  along  with  the  requisite  quan- 
tity of  recently  ignited  cupric  oxid,  leaving  space  for  the  passage  of 
the  gases  produced.  The  tube  is  then  placed  in  the  furnace  and  its 
open  end  connected  with  a  U  tube,  6,  filled  with  fused  CaCh,  or  with 
fragments  of  pumice  moistened  with  concentrated  H2SO4,  whose 
weight  has  been  determined,  and  whose  purpose  it  is  to  absorb  the 
EhO  produced.  This  first  U  tube  is  connected  with  a  "Liebig's  bulb" 
containing  a  strong  solution  of  KHO,  c,  and  this  in  turn  with  another 
U  tube  in  all  respects  similar  to  the  first,  d,  both  c  and  d  having  been 
previously  weighed.  The  purpose  of  c  is  to  absorb  the  C(>2  produced, 
that  of  d  to  retain  water  carried  over  from  c  by  the  current  of  gas. 
The  combustion  tube  is  then  carefully  heated  until  the  evolution  of 
gases  ceases,  when  the  closed,  drawn-out  end  of  the  tube  is  broken 
and  connected  with  a  gasometer  containing  pure,  dry  oxygen,  a  cur- 


\ 


FIG.  32. 

rent  of  which  is  passed  slowly  through  the  apparatus  to  bring  the  last 
portions  of  the  products  of  combustion  into  the  absorbing  apparatus. 
Finally  the  U  tubes  and  the  KHO  bulb  are  again  weighed.  The 
increase  in  weight  of  5  is  the  weight  of  H2<3  produced,  every  9  parts 
of  which  represent  1  part  of  H.  The  increase  in  weight  of  c  and  d 
is  the  weight  of  C02  produced,  every  44  parts  of  which  represent  12 
parts  of  C.  If  the  substance  analyzed  contain  N,  Cl,  Br  or  I,  a  heated 
column  of  pure  metallic  Cu  is  interposed  toward  the  open  end  of  the 
combustion  tube,  to  reduce  any  oxids  of  N  produced  to  N,  and  to 
retain  the  Cl,  Br  or  I.  If  the  substance  contain  S,  a  layer  of  lead 
peroxid  is  similarly  placed  to  retain  the  S  as  PbSO4. 

If  the  substance  consist  of  C,  H  and  O,  the  C  and  H  are  deter- 
mined in  the  manner  above  described,  and  the  difference  between  the 
sum  of  their  weights  and  that  of  the  substance  burnt  is  the  amount 
of  O. 

Nitrogen  is  most  readily  determined  by  the  method  of  Kjeldahl. 
A  known  weight  of  the  substance  is  dissolved  by  heating  it  in  concen- 
trated H2SO4.  Potassium  permanganate  is  then  added  until  the  mix- 


COMPOUNDS    OF   CAEBON  221 

ture  is  green.  The  N  contained  in  the  substance  is  thus  converted 
into  ammonia.  The  strongly  acid  liquid  is  diluted,  rendered  alkaline 
by  addition  of  NaHO,  and  the  NHs  is  distilled  over  into  a  receiver 
containing  a  known  quantity  of  acid.  The  amount  of  NHs  produced 
is  calculated  from  the  amount  of  acid  neutralized,  and  every  17  parts 
of  NHs  represent  14  parts  of  N.  In  the  analysis  of  nitro-  and  cyano- 
gen compounds  sugar  is  added,  and  in  that  of  nitrates,  benzoic  acid. 

Two  other  methods  of  determining  N  are  in  general  use :  That  of 
Dumas,  in  which  the  substance  is  burnt  in  a  manner  very  similar  to 
that  above  described,  and  the  N  produced  is  collected  and  measured. 
The  weight  of  N  is  then  calculated  from  the  volume,  with  the  neces- 
sary corrections  for  variations  of  temperature  and  pressure.  In  the 
method  of  Will  and  Varrentrap  the  N  of  the  compound  is  converted 
into  NHs  by  heating  with  a  caustic  alkali,  and  the  amount  of  NHs  is 
determined  as  in  Kjeldahl's  method.  For  the  details  of  these  pro- 
cesses and  for  methods  of  determination  of  other  elements  in  organic 
compounds  the  student  is  referred  to  works  on  quantitative  analysis, 
such  as  that  of  Fresenius.  The  details  of  the  directions  must  be 
rigidly  observed  to  avoid  error. 

Determination  of  Molecular  Weights. — The  percentage  compo- 
sition having  been  determined,  the  simplest  corresponding  ratio  of  the 
atoms  in  the  molecule  is  obtained  by  dividing  the  percentage  of  each 
element  by  its  atomic  weight.  Thus  if  analyses  be  made  of  formic 
aldehyde,  acetic  acid,  methyl  formate,  lactic  acid  and  glucose,  the 
results  in  each  case  will  be : 

Carbon. 40.00  per  cent. -s- 12  =  3.33  =  1 

Hydrogen 6.67     "      "     -5-    1  =  6.67=2 

Oxygen .53.33     "       "     -f- 16  =  3. 33  =  1 

and  the  simplest  empirical  formula  of  all  of  the  substances  mentioned 
is  therefore  CEkO.  The  molecular  weight  of  formic  aldehyde  is  30; 
its  formula  is  therefore  CEbO  (12+2+16).  The  molecular  weights 
of  acetic  acid  and  of  methyl  formate  are  60:  they,  therefore,  each 
have  the  formula  C2H<tO2 .  The  molecular  weight  of  lactic  acid  is  90 
and  that  of  glucose  180:  the  formula  of  the  former  is,  therefore, 
C3H6O3,  and  that  of  the  latter  C6Hi2O6. 

If  the  substance  be  one  which  can  be  vaporized  without  decompo- 
sition, its  molecular  weight  is  derived  from  its  specific  gravity  as 
referred  to  hydrogen  in  the  manner  already  described  (p.  38).  The 
process  for  determining  the  specific  gravity  now  generally  adopted  is 
that  of  Victor  Meyer.  (See  Ganot's  Physics,  15th  Am.  Ed.,  p.  381, 
or  other  works  upon  that  subject.) 

Three  other  physical  methods  of  determining  molecular  weights 
are  available: 


222 


MANUAL    OF    CHEMISTRY 


1.  From  Osmotic  Pressure. — It  has  beeii  stated  (p.  20)  that  sub- 
stances in  solution  exert  a  pressure  equal  to  that  which  would  be 
exerted  by  an  equal  amount  of  the  substance,  if  it  were  converted 
into  gas,  and  occupied  the  same  volume,  at  the  same  temperature,  as 
the  solution.  Therefore  the  law  of  Avogadro  has  the  same  value  for 
solutions  as  for  gases,  and  equal  volumes  of  solutions  exerting  equal 
osmotic  pressures  at  the  same  temperature  contain  equal  numbers  of 
molecules.  Applying  this  fact  in  the  same  manner  as  the  law  of 
Avogadro  is  applied  in  the  case  of  gases,  the  molecular  weight  may  be 
derived  from  the  osmotic  pressure  by  the  formula: 


M=- 


a.6218  (273+t) 


in  which  M=the  molecular  weight ;  a=the  weight  of  dissolved  sub- 
stance in  1  cc.,  expressed  in  grams;  t=the  observed  temperature; 
and  P=the  osmotic  pressure.  The  solutions  used  must  be  dilute,  and 
the  "semi -permeable"  membrane  used  is  either  a  living  plant  cell  or 
an  artificial  membrane  of  copper  ferrocyanid. 

2.  From  Elevation  of  the  Boiling  Point. — Solutions  have  a  lower 
vapor  pressure  than  the  pure  solvent  at  the  same  temperature,  and 

consequently  the  former  boil  at  a 
higher  temperature  than  the  latter. 
The  elevation  of  the  boiling  point  is 
proportionate  to  the  quantity  of  sub- 
stance dissolved,  if  that  substance  be 
non- volatile.  If  molecular  quan- 
tities be  considered,  it  is  found 
that  equal  elevations  are  observed 
with  solutions  containing  equal 
molecular  weights  of  different  sub- 
stances in  the  same  volume  of  sol- 
vent. And,  with  different  solvents, 
the  elevations  are  equal  when  the 
same  quantity  of  substance  is  dis- 
solved in  molecular  quantities  of  the 
several  solvents. 

Beckman's  method  is  the  one  generally  used:  The  special  appa- 
ratus used  consists  of  a  peculiarly -shaped  boiling  flask  (Fig.  33)  and 
a  very  delicate  thermometer.  The  body  of  the  flask  is  filled  with 
glass  pearls  to  within  1  cm.  of  the  lower  opening  of  the  con- 
densor  tube  /.  The  flask,  with  stoppers  in  the  three  openings,  is 
first  weighed.  The  solvent  is  then  introduced  to  the  level  e,  and  the 
flask  reweighed.  The  difference  is  the  weight  of  the  solvent  used. 


FIG.  33. 


COMPOUNDS    OF    CAEBON  223 

The  flask  is  then  mounted,  surrounded  by  an  asbestos  mantle,  in  a 
position  to  be  heated;  the  thermometer  is  adjusted  in  the  neck  d  with 
its  bulb  immersed  in  the  solvent;  the  neck  b  is  connected  with  a 
condenser.  The  solvent  is  then  boiled  and  the  temperature  noted. 
A  known  weight  of  the  substance  is  then  introduced  through  the  neck 
c  and  the  boiling  point  again  noted.  The  molecular  weight  is  calcu- 
lated by  the  formula:  w=p.-^— ;  in  which  p=the  weight  in  grams  of 
substance  dissolved  in  100  cc. ;  d=the  molecular  rise  in  boiling  point 
of  the  solvent;  and  d1:=the  observed  rise  in  boiling  point.  The  value 

t2 

of  d  is  determined  by  the  formula:  d=0.02.  ;  in  which  t=the  ab- 
solute boiling  point,  and  w=the  heat  of  evaporation  of  the  solvent. 
For  ether  the  value  of  d  is  21.1°,  for  chloroform  36.6°,  and  for  acetic 
acid  25. 3°. 

3.  From  the  Depression  of  the  Freezing  Point. — The  law  of  Raoult 
(see  p.  17)  is  utilized  to  determine  molecular  weights.    Various  forms 
of  apparatus  are  used,  in  all  of  which  the  freezing  point  of  the  sol- 
vent is  first  determined,  and  then  that  of  the  same  liquid  after  addi- 
tion of  a  known  weight  of  the  substance.     The  molecular  weight  is 

calculated  by  the  formula:  m— -^— ;  in  which  t=the  constant  for 
the  solvent  used;  p=the  weight  in  grams  of  the  substance  dissolved 
in  100  grams  of  the  solvent;  and  c=the  depression  observed. 

4.  Chemical  Methods  are  also  resorted  to  to  determine  molecular 
weights.     They  consist   in   producing    derivatives,   which   are    then 
analyzed  and  the  results  thus  obtained  compared  with  the  formulae 
deducible  from  the  analysis  of  the  original  compound.     These  meth- 
ods are  sometimes  exceedingly  complicated,  in  other  cases  very  simple. 
When  the  substance  is  a  base  or  an  acid  it  is  converted  into  a  mineral 
ester  or  into  a  salt,  and  the  combined  mineral  acid  or  metal  is  deter- 
mined.    For  example:  Acetic  acid  and  lactic  acid  both  have  the  per- 
centage composition  0=40.00%,  H=6.67%,  O=53.33%,  corresponding 
to  the  formula  CH^O,  or  some  multiple  thereof.     The  atomic  weight 
of  silver  is  107.7.     If  the  two  acids  are  converted  into  their  silver 
salts,   and   the   amount   of   silver   in   each   determined,    the   acetate 
will  be    found  to  contain  64.6%  of  silver,  and  the  lactate  54.8%. 
If  both  acids  are   monobasic  the  former  percentage  of   silver  cor- 
responds to  the  formula  C2H3O2Ag,  and  the  latter  to  the  formula 
C3H5O3Ag. 

The  basicity  of  the  acid  is  determined  by  measuring  the  increase 
of  molecular  conductivity  (p.  44)  of  solutions  of  the  sodium  salt  of 
the  acid  with  increasing  dilution.  With  the  sodium  salts  of  mono- 
basic acids  this  increase  is  from  10  to  13  units  with  dilution  of  32- 
1024  litres  for  the  equivalent  of  the  substance,  with  sodium  salts  of 


224  MANUAL    OF    CHEMISTRY 

dibasic  acids  28  to  31,  with  those  of  tetrabasic  acids  about  40,  and 
with  those  of  pentabasic  acids  about  50  units. 

Determination  of  Constitution.— The  properties  of  organic  com- 
pounds depend,  therefore,  not  only  upon  their  composition,  but  also 
upon  their  constitution,  i.  e.,  upon  the  arrangement  of  the  atoms  in 
the  molecule  (see  p.  53).  The  constitution  of  a  substance  is  deter- 
mined by  a  study  of  the  methods  of  its  formation,  of  the  products 
of  its  decomposition,  and  of  substances  produced  by  the  introduction 
of  other  elements  or  groups  into  its  molecule.  A  statement  of  the 
more  important  principles,  and  one  or  two  examples,  must  suffice 

here. 

The  carbon  atom  is  quadrivalent  in  almost  all,  if  not  in  all  organic 
compounds.  In  the  few  in  which  it  is  considered  as  bivalent,  as  in 
carbon  monoxid,  CO,  and  the  isonitrils,  (C2H5)—  N=C,  the  oxygen 
may  be  considered  to  be  quadrivalent,  and  the  nitrogen  quin- 
quivalent, in  which  case  the  carbon  would  be  quadrivalent. 

The  carbon  atoms  may  unite  with  each  other  in  three  ways: 
(1)  Two  carbon  atoms  may  exchange  a  single  valence  in  their  union, 
forming  a  hexavalent  group, =C — C=;  (2)  they  may  unite  with  ex- 
change of  two  valences,  forming  a  quadrivalent  group,  =C=C=; 
or,  (3)  they  may  unite  with  exchange  of  three  valences,  forming  a 
bivalent  group,  — C=C — .  These  are  referred  to  as  single,  double 
and  treble  linkages,  respectively. 

Only  those  compounds  in  which  all  of  the  linkages  are  single  are 
saturated  compounds,  i.  e.,  compounds  in  which  all  of  the  possible 
valences  of  the  constituent  atoms  are  satisfied.  Compounds  contain- 
ing two  or  more  carbon  atoms  doubly  or  trebly  linked  are  unsatu- 
rated. 

Other  atoms  or  radicals  can  be  introduced  into  a  saturated  mole- 
cule only  by  substitution,  i.  e.,  by  causing  them  to  take  the  place  of 
other  atoms  or  radicals  of  equivalent  valence,  removed  at  the  same  time. 
Thus  when  chloroform  (itself  a  derivative  of  marsh  gas,  CH4)  is  con- 
verted into  tetrachlorid,  the  remaining  hydrogen  is  removed  as  hydro- 
chloric acid  CHCla+Cl^CCU+HCl. 

Unsaturated  compounds  may  be  similarly  modified  both  by  substi- 
tution and  also  by  addition,  in  the  latter  case  the  double  or  treble 
linkage  is  reduced  to  a  single  or  double  one.  Thus  ethylene  may 
yield  ethylene  chlorid  by  the  addition:  H2C:CH2+C12=C1H2C.CH2C1; 
or,  by  addition  and  substitution,  carbon  hexachlorid:  H2C:CH2+ 
5C12=C13C.CC13+4HC1. 

In  the  above  substitutions  the  chlorin  is  not  only  added  to  the  mole- 
cule operated  upon;  it  also  removes  hydrogen  by  combining  with  it. 
Similarly,  in  oxidations  O  removes  Eb,  as  when  alcohol  is  oxidized 
to  acetic  acid:  C2H6O+ O2=C2H4O2-i-H2O.  Consequently  in  oxidations 


COMPOUNDS    OF    CARBON  225 

an  even  number  of  hydrogen  atoms  is  always  removed.  The  tendency 
to  the  formation  of  water  is  so  strong  that  in  reactions  in  which  two 
or  more  hydroxyl  groups  should  unite  with  the  same  carbon  atom, 
water  almost  invariably  splits  off  and  oxygen  unites  doubly  with  the 
carbon.  Thus  caustic  potash  does  not  act  upon  ethidene  chlorid  to 
produce  a  glycol  according  to  the  equation  CHs.CHC^^^KHO^ 
CH3.CH(OH)2-f2KCl,  but  to  produce  an  aldehyde  according  to  the 
equation,  CH3.CHCl2+2KHO=CH3.CHO+H2O+2KCl. 

Exceptions  to  this  rule  occur  when  the  carbon  atom  is  linked  to 
another  carbon  atom  contained  in  a  highly  oxidized  or  halide  group, 
as  in  the  compounds: 

COOH  CC13  COOH 

l/on  /OH 


COOH 

Gly oxalic  acid.  Chloral  hydrate.  Mesoxalic  acid, 

Usually  when  an  atom  or  group  replaces  another  in  a  compound 
it  occupies  the  position  vacated  by  that  which  is  removed,  as  when 
alcohol  is  formed  by  the  action  of  caustic  potash  upon  ethyl  iodid: 
CH3.CH2l+KHO  =  CH3.CH2OH+KI.  There  is  an  exception  to 
this  rule  when  an  unsaturated  compound  may  yield  either  another 
unsaturated  compound  in  obedience  to  the  rule  or  an  isomeric  satu- 
rated compound  in  violation  to  it,  the  more  stable  saturated  com- 
pound is  formed.  Thus  the  hydration  of  vinyl  bromid,  CH2:CHBr, 
does  not  produce  vinyl  alcohol,  CH2:CHOH,  but  its  isomere:  aldehyde, 
CHs.CHO.  Indeed  unsaturated  compounds  are  frequently  converted 
into  saturated  isomeres  by  intramolecular  transposition  of  atoms  by 
mere  application  of  heat. 

The  genesis  of  ethylic  alcohol  from  the  action  of  caustic  potash 
upon  ethyl  iodid:  CH3.CH2I+KHO=CH3.CH2OH+KI,  shows  that 
the  alcohol  contains  the  univalent  group  CH2OH,  or 

H          OH 


/\ 
H 

which,  on  oxidation,  may  lose  two  atoms  of  hydrogen  with  formation 
of  either  one  of  the  two  univalent  groups  CHO,  or  COOH; 

.0  /OH 

or  -Cf          or  0=C(          ; 
\H 

which  occur  in  the  products  of  oxidation  of  ethylic  alcohol:  aldehyde 
and  acetic  acid. 

The  groups  CH2OH,   CHO  and  COOH,   referred   to   above,   are 
examples  of  the  so-called  characterizing  groups  which  exist  in  the 
15 


MANUAL    OF    CHEMISTRY 


molecules  of  different  classes  of  substances.  The  following  are  the 
more  commonly  recurring  characterizing  groups,  and  the  classes  of 
substances  in  which  they  occur: 


(CH2OH)' 

=  HO/C\ 

in  primary  alcohols, 

(CHOH)" 

=  H\c= 

"  secondary  alcohols, 

(COH)'" 

=  ;C.OH 

"  tertiary  alcohols, 

(CHO)' 

=  0=C/H 

*'  aldehydes, 

(CO)" 

=  0:C: 

"  ketones,  called  carbonyl,* 

(COOH)' 

=  0=C<OH 

u  acids,  called  carboxyl, 

(S02OH)' 

=  8><°H 

"  sulfonic  acids, 

(NH2)' 

=  H2:N. 

"  amido  compounds, 

(NH)" 

=  H.N: 

"  imido  compounds, 

(NO,)' 

-8>- 

"  nitro  compounds, 

(NO)' 

=  0:N. 

"  nitroso  compounds. 

Nomenclature  of  Organic  Compounds.  —  The  vast  number  and 
great  variety  of  structure  of  organic  compounds  make  it  difficult  to 
devise  a  system  of  nomenclature  which  will  apply  to  the  more  com- 
plex derivatives  without  producing  names  which  are  most  complicated 
and  difficult  of  pronunciation.  Indeed,  in  view  of  the  constantly 
increasing  number  of  carbon  compounds,  no  complete  system  of  no- 
menclature is  as  yet  possible.  The  most  recent  attempt  to  formulate 
one  is  that  of  the  Geneva  Commission  of  1892.  In  this  system  the 
names  of  the  hydrocarbons  serve  as  the  roots  from  which  the  names 
of  their  derivatives  are  constructed  by  the  addition  of  syllables  indi- 
cating the  function  (see  p.  42)  of  the  substance.  Thus  the  alcohols 
are  indicated  by  the  syllable  ol,  the  aldehydes  by  al,  the  ketones  by  on, 
and  the  acids  by  the  word  add.  The  "Geneva"  name  of  ethylic  alco- 
hol would  be  ethanol,  that  of  acetic  aldehyde  ethanal  and  that  of 
acetic  acid  ethan-acid.  These  names  have  not  come  into  general  use. 

In  the  nomenclature  generally  followed  the  name  of  a  substance 
is  made  up  of  the  name  of  that  of  the  class,  or  "function,"  to  which 
the  substance  belongs,  as  addt  alcohol,  ketone,  ester,  etc.,  to  which 
are  added  a  qualifying  word  derived  from  the  origin  of  the  body,  as 
lactic  acid,  acetic  acid,  etc.,  or  from  its  composition,  as  methylic  alco- 
hol, ethylic  ether,  etc.,  and  the  names  of  any  radicals  which  have  been 
introduced  into  the  molecule  of  the  parent  compound.  Thus  the 

*This  group  also  exists  in  other  compounds,  as  in  the  aldehydes  and  acids  in  the  manner  indi- 
cated in  the  text,  and  in  compounds,  such  as  carbonyl  chlorid,  OOCk,  urea,  NHa.CO.NHa,  etc. 


.. 


COMPOUNDS    OF    CARBON  227 


name  of  the  substance  COOH.CH2  (NH.CH3)  is  methyl -amido- acetic 
acid,  in  which  "acetic  acid"  indicates  that  it  is  derived  from  acetic 
acid,  COOH.CH3,  the  syllable  amido  that  NH2  has  been  substituted 
for  H  in  the  CH3  of  the  acid,  and  methyl  that  CH3  has  been  substi- 
tuted for  H  in  NH2. 

The  names  of  the  univalent  radicals  terminate  in  yl,  as  methyl 
(CH3)',  ethyl  (C2H5)',  acetyl  (C2H3O)',  etc.  Those  of  bivalent  radi- 
cals terminate  in  ene,  as  methylene,  (CH2)",  ethidene  (C2H4)",  etc., 
and  those  of  the  trivalent  radicals  in  enyl  or  in  ine,  as  methenyl  or 
methine  (CH)"',  ethenyl  or  ethine  (C2H3)/7/,  etc. 

Classification  of  the  Carbon  Compounds.  —  The  hydrocarbons, 
consisting  of  carbon  and  hydrogen  only,  constitute  the  framework  of 
the  classification  adopted,  all  other  carbon  compounds  being  consid- 
ered as  derivable  from  the  hydrocarbons  by  substitution  or  by 
addition. 

Carbon  compounds  are  divided  into  two  great  classes,  differenti- 
ated by  the  manner  in  which  the  carbon  atoms  are  linked  together: 

A.  OPEN  CHAIN  COMPOUNDS,  also  called  acyclic,  fatty,  or  aliphatic 
(aAei<£ap=fat)  compounds.     In   these  compounds  the  carbon  atoms 
are  attached  to  each  other  in  an  open  or  arborescent  chain,  in  which 
two  or  more  carbon  atoms  are  linked  to  but  one  other  carbon  atom, 
as  in  the  compounds : 

H    H    H    H    H   H 

II  II  I  I  x  f^TT      r^TT 

H— C— C— C— C— C-C— H  CH3.CH2.CH 

I       I      I      I       I      I  \CH3 

H    H    H    H   H   H 

In  the  hydrocarbons  of  this  class  the  number  of  hydrogen  atoms, 
or  this  number,  plus  the  number  of  univalent  atoms  that  can  be  in- 
troduced into  the  molecule  by  addition,  is  equal  to  twice  the  number 
of  carbon  atoms  plus  two. 

B.  CLOSED  CHAIN  COMPOUNDS,  also  called  cyclic  or  aromatic  com- 
pounds.    These  compounds  contain  one  or  more  closed  chains,  rings, 
or  nuclei  in  which  each  carbon  atom  is  linked  to  at  least  two  other 
carbon  atoms,  or  their  equivalent,  as  in  the  compounds: 

H  H2  H       H 

1  »-  i    i 


C 

C  H    H    H    H 

^\ 

/Mill 

H—  C        C—  H 

H2=C        C—  C—  C—  C—  H 

III 

1        Ml' 

|| 

H  H    H 

H—  C        C—  H 

Hr*i          /~*      TT 
0=^,              ^  Ho 

V 

\/ 

C 

N 

i 

1 

H 

H 

Benzene. 

Conttn. 

H— C        C        C— H 


H—  C        C        C-H 


C        C 

I      I 

H        H 

Naphthalene. 


228 


MANUAL    OF    CHEMISTRY 


The  closed  chain  compounds  are  subdivided  into  two  classes: 

I.  Carbocyclic  compounds,  in  which  the  ring  or  rings  consist  of 
carbon  atoms  exclusively,  as  in  benzene  and  naphthalene,  and 

II.  Heterocyclic  compounds,  in  which  atoms  of  elements  other  than 
carbon  enter  into  the  composition  of  the  ring,  as  in  coniin. 


HYDROCARBONS  229 


CHAIN,  ALIPHATIC,  ACYCLIC   OR   FATTY 
COMPOUNDS. 

HYDROCARBONS. 

Six  series  are  known : 

A.  Methane,    or   Paraffin    Series.      These   are   saturated   com- 
pounds and  have  the  algebraic  formula,  CnH2n+2.     Their  names  ter- 
ninate  in  uane,"  e.  g.,  Butane,  CH3.CH2.CH2.CH3. 

B.  Olefin    Series,  containing  two  doubly-linked   carbon  atoms. 
General  formula  CnH2n.     Their-  names    terminate   in  "ene,"    e.    g., 
Butene,  CH2:CH.CH2.CH3. 

C.  Acetylene  Series,  containing  two  trebly-linked  carbon  atoms. 
Algebraic  formula,  CnH.2n— 2.     Their  names  terminate  in  "ine,"  e.  g., 
Propine,  CH;C.CH3. 

D.  Diolefin   Series,  containing   two  pairs  of  doubly -linked  car- 
bon atoms.     Algebraic  formula,  CnH2»_2,  isomeric  with  the  members 
of  the  acetylene  series.     Their  names  terminate  in  "diene,"  e.  g., 
Propadiene,  CH2:C:CH2. 

E.  Olefin-acetylene  Series,  containing  both  doubly-  and  trebly- 
linked  carbon  atoms.     General  formula,  CnH2n_4.     Their  names  ter- 
minate in  "one,"  eg.,  Butone,  H2C:CH.C.:CH. 

F.  Diacetylene    Series,    containing   two   pairs   of    trebly -linked 
carbon  atoms.     Algebraic  formula,  CnH2n— e-     Their  names  are  con- 
structed by  prefixing  the  syllable  "di"  to  the  name  of  the  hydrocar- 
bon of  series  C,  from  which  they  are  derivable  by  fusion  and  elimi- 
nation of  H2  or  its  equivalent,  e.  g.,  Diacetylene,  HCiC.CiCH.     The 
sixth  terms,  of  which  there  are  two  isomeres:  Dipropargyl,  HClC.CH2.- 
CH2.CiCH,    and    Dimethyl   diacetylene,    H3C.CiC.GC.CH3,   are   iso- 
meric with  benzene,  the  most  important  of  the  closed  chain  hydro- 
carbons. 


SATURATED  COMPOUNDS  — METHANE  SERIES. 

HYDROCARBONS. 

The  saturated  hydrocarbons  at  present  known  extend  in  unbroken 
series  from  methane,  CH.4,  to  tetracosane,  C24H5o;  and  above  that 
some  members  are  known  as  high  as  dimyricyl,  CeoHi^.  The  alge- 
braic formula  of  the  series  is  CnH2n+2.  They  are  called  paraffins 
because  of  their  great  stability  (parum=litt\Q,  a#wis=affinity) ;  and 


230  MANUAL    OP    CHEMISTRY 

also  alkanes.     They  are  also  considered  as  the  hydrids  of  the  alco- 
holic radicals,  CnH2n+i,  methyl,  ethyl,  etc.,  which  are  called  alkyls. 

In  the  higher  terms  of  the  series,  above  the  third,  there  exist  two 
or  more  isomeres,  increasing  progressively  in  number  with  an  in- 
creasing number  of  carbon  atoms.  Thus  there  are  three  having  the 
empirical  formula,  CsHi2: 


(1)  C 

(2)  C 


CH3.CH2.CH2.CH2.CH3,  (3)  CH3\ 

CHsN^TT  pcrr    r<TT  ,_  j  CH3     C.CH3. 

CH3/CH-CH2'CH3j  and'  CH3/ 

Hydrocarbons  and  their  derivatives  having  the  "  unbranched " 
structure  shown  in  formula  (1)  above,  are  designated  as  "normal" 
compounds  ;  those  derived  from  (2)  are  called  "iso"  compounds; 
and  those  derived  from  (3)  "meso"  compounds. 

The  number  of  possible  isomeres  increases  rapidly  with  an  in- 
creasing number  of  carbon  atoms.  It  has  been  calculated  that  the 
number  of  possible  isomeres  with  increasing  values  of  n  are  as 
follows  : 

ill  235 

9  18  35  75  159  357 

Many  of  these  hydrocarbons  exist  in  nature,  in  petroleum,  and  in 
the  gases  accompanying  it.  They  may  be  produced  by  the  follow- 
ing general  reactions : 

(1)  By  the  action  of  finely -divided  zinc,  silver  or  copper,  or  of 
sodium  either  alone,  at  elevated  temperatures,  or  in  the  presence  of 
H2O,  upon  the  corresponding  iodids  :  2C2H5H-Zn2+2H2O^ZnH202+ 
ZnI2+2C2H6,  or,  2C2H5I-fNa2=2NaH-C4Hio. 

(2)  By  electrolysis  of  the  corresponding  fatty  acid  :    2C2H4O2= 
2C02+C2H6+H2. 

(3)  By  the  action  of  the  organo-zincic  derivative  upon  the  iodid 
of  the  alcoholic  radical,  upon  the  corresponding  olefin  iodid,  or  upon 
the  allylic  iodid  (p.  371). 

(4)  By  the  action  of  highly  concentrated  hydriodic  acid  at  275°- 
300°  (527°-572°  F.)  upon    hydrocarbons  of   the   ethene  and  ethine 
series;  upon  alcohols,  amins,  etc.     This  is  a  method  of  hydrogenation 
applicable  in  many  other  cases. 

(5)  By  the  destructive  distillation  of  many  organic  substances. 
General  Properties. — They  are  gaseous,  liquid,  or  solid,  and  have 
sp.  gr.  and  boiling  points  increasing  with  the  number  of  C  atoms. 
The  first  four  members  are  gaseous  at  the  ordinary  temperature,  those 
above  Ci5H32  are  crystalline  solids;  the  intermediate  ones  are  color- 
less liquids.  They  are  lighter  than  H2O,  neutral,  insoluble  in  H2O, 


HYDROCARBONS  231 

soluble  in  alcohol,  ether,  and  in  liquid  hydrocarbons.     Their  odor  is 
faint  and  not  unpleasant. 

They  are  very  stable  and  incapable  of  modification  by  addition. 
Chlorin  and  bromin  decompose  them,  with  formation  of  products  of 
substitution.  They  are  inflammable  and  burn  with  a  luminous  flame. 
Nitric  acid  forms  nitro-  derivatives  with  the  higher  terms. 

Methyl  Hydrid  —  Methane  —  Marsh-gas  —  Light  carburetted  hydro- 
gen —  Fire-damp  —  CELt  —  16  —  is  given  off  in  swamps  as  a  product  of 
decomposition  of  vegetable  matter,  in  coal  mines,  and  in  the  gases 
issuing  from  the  earth  in  the  vicinity  of  petroleum  deposits.  It  is 
also  formed  during  putrefaction  of  protein  bodies  and  fermentation  of 
carbohydrates.  From  these  origins  it  exists  in  intestinal  gases, 
sometimes  to  the  extent  of  26.5  per  cent.  Coal-gas  contains  it  in 
the  proportion  of  36-50  per  cent.  It  may  be  prepared  by  strongly 
heating  a  mixture  of  sodium  acetate  with  sodium  hydroxid  and  quick- 
lime. Its  complete  synthesis,  which  is  of  theoretic  interest,  may  be 
effected  in  several  ways:  (1)  Carbon  disulfid  is  first  produced  by 
passing  vapor  of  sulfur  over  coal,  heated  to  redness  :  C-f-  82=082. 
This  may  either  be  passed,  along  with  hydrogen  sulfid,  over  red- 
hot  copper,  when:  CS2+2H2S-{-8Cu=CH4+4Cu2S,  or,  (2)  it  maybe 
converted  into  carbon  tetrachlorid  by  the  reaction: 
S2C12  ;  and  this  reduced  by  nascent  hydrogen  : 
4HC1.  (3)  Carbon  monoxid,  prepared  by  heating  carbon  in  a  lim- 
ited quantity  of  air,  is  reduced  by  hydrogen  when  the  two  are  treated 
with  the  induced  electric  current:  CO+3H2=CH4+H2O.  (4)  Alu- 
minium carbid  is  decomposed  by  water  according  to  the  equation: 


It  is  a  colorless,  odorless,  tasteless  gas;  very  sparingly  soluble  in 
sp.  gr.  0.559A.  At  high  temperatures,  it  is  decomposed  into  C 
and  H.  It  burns  in  air  with  a  pale  yellow  flame.  Mixed  with  air  or 
O  it  explodes  violently  on  contact  with  flame,  producing  water  and 
carbon  dioxid;  the  latter  constituting  the  after-damp  of  miners.  It 
is  not  affected  by  Cl  in  the  dark,  but,  under  the  influence  of  diffuse 
daylight,  one  or  more  of  the  H  atoms  are  displaced  by  an  equivalent 
quantity  of  Cl.  In  direct  sunlight  the  substitution  is  accompanied 
by  an  explosion. 

Petroleum.  —  Crude  petroleum  varies  in  color  from  a  faintly  yel- 
lowish tinge  to  a  dark  brown,  nearly  black,  with  greenish  reflections. 
The  lighter  -colored  varieties  are  limpid,  and  the  more  highly  colored 
of  the  consistency  of  thin  syrup.  The  sp.  gr.  varies  from  0.74  to 
0.92.  Crude  petroleums  consist  of  normal  paraffins  (the  lowest  terms 
of  the  series  being  found  in  the  gases  accompanying  petroleum  and 
held  in  solution  by  the  oil  under  the  pressure  it  supports  in  natural 
pockets),  besides  hydrocarbons  of  the  olefin,  paraffene,  and  benzene 


232  MANUAL    OF    CHEMISTRY 

series.  They  also  contain  varying  quantities  of  sulfur  compounds, 
which  communicate  a  disgusting  odor  to  some  oils. 

The  crude  oil  is  highly  inflammable,  usually  highly  colored,  and 
is  prepared  for  its  multitudinous  uses  in  the  arts  by  the  processes  of 
distillation  and  refining.  The  products  of  lowest  boiling  point  are 
usually  consumed,  but  are  sometimes  condensed. 

The  principal  products  of  petroleum  are  :  Cymogene,  boils  at  0° 
(32°  F.),  used  in  ice  machines;  Rhigolene,  a  highly  inflammable 
liquid,  sp.  gr.  about  0.60,  boils  at  about  20°  (68°  F.),  used  to  pro- 
duce cold  by  its  rapid  evaporation.  Petroleum  ether,  boils  at  40°-70° 
( 104°-1 58°  F.),  used  as  a  solvent.  Gasolene,  boils  from 45°  (113°  F.) 
to  76°  (168.8°  F.),  used  as  a  fuel  and  for  the  manufacture  of  "air 
gas."  Naphtha,  divided  into  three  grades,  C,  B,  and  A,  boils  from 
82.2°  (180°  F.)  to  148.8°  (300°  F.),  used  as  a  solvent  for  fats,  etc., 
and  in  the  manufacture  of  "water  gas."  Sometimes  called  "safety 
oil."  Benzine,  or  benzolene,  boils  from  148°  (298°  F.)  to  160° 
(320°  F.),  used  as  a  solvent  in  making  paints  and  varnishes.  The 
most  important  product  of  petroleum  is  that  portion  which  distils 
between  176°  (349°  F.)  and  218°  (424°  F.),  and  which  constitutes 
kerosene  and  other  oils  used  for  burning  in  lamps.  An  oil  to  be 
safely  used  for  burning  in  lamps  should  not  "flash,"  or  give  off  in- 
flammable vapor,  below  37.4°  (100°  F.),  and  should  not  burn  at 
temperatures  below  149°  (300°  F.).  The  better  grades  of  kerosene 
have  a  flash  point  of  from  110°  F.  to  150°  F. 

From  the  residue  remaining  after  the  separation  of  the  kero- 
sene, many  other  products  are  obtained.  Lubricating  oils,  of  too 
high  boiling-point  for  use  in  lamps.  Paraffin,  a  white,  crystalline 
solid,  fusible  at  45°-65°  (113°-149°  F.),  which  is  used  in  the  arts  for 
a  variety  of  purposes  formerly  served  by  wax,  such  as  the  manufac- 
ture of  candles.  In  the  laboratory  it  is  very  useful  for  coating  the 
glass  stoppers  of  bottles,  and  for  other  purposes,  as  it  is  not  affected 
by  acids  or  by  alkalies.  It  is  odorless,  tasteless,  insoluble  in  H2O 
and  in  cold  alcohol;  soluble  in  boiling  alcohol  and  in  ether,  fatty  and 
volatile  oils  and  mineral  oils.  It  is  also  obtained  by  the  distillation 
of  certain  varieties  of  coal,  and  is  found  in  nature  in  fossil  wax  or 
ozocerite. 

The  products  known  as  vaseline,  petrolatum,  (U.  S.),  cosmoline, 
etc.,  which  are  now  so  largely  used  in  pharmacy  and  perfumery,  are 
mixtures  of  paraffin  and  the  heavier  petroleum  oils.  Their  consist- 
ency depends  upon  the  relative  proportion  of  the  higher  paraffins,  of 
increasing  fusing-point,  which  they  contain,  from  the  oily  petro- 
latum liquidum  (U.  S.),  to  the  hard  petrolatum  durum  (U.  S  ). 
Like  petroleum  itself,  its  various  commercial  derivatives  are  not 
definite  compounds,  but  mixtures  of  the  hydrocarbons  of  this  series. 


HALOID    DERIVATIVES    OF    THE    PARAFFINS  233 

HALOID   DERIVATIVES   OF   THE  PARAFFINS. 

By  the  action  of  Cl  or  Br  upon  the  paraffins,  or  by  the  action  of 
HC1,  HBr  or  HI  upon  the  corresponding  hydroxids,  compounds  are 
obtained  in  which  one  of  the  H  atoms  of  the  hydrocarbon  has  been 
replaced  by  an  atom  of  Cl,  Br  or  I:  C^e+BrsF^HsBr+HBr,  or 
C2H5OH+HC1=:,C2H5C1+H2O.  These  compounds  may  be  considered 
as  the  chlorids,  bromids  or  iodids  of  the  alcoholic  radicals,  and  are 
known  as  the  haloid  ethers  or  haloid  esters. 

When  Cl  is  allowed  to  act  upon  CH4,  it  replaces  a  further  number 
of  H  atoms  until  finally  carbon  tetrachlorid,  CCU,  is  produced.  Con- 
sidering marsh  gas  as  methyl  hydrid,  CH3.H,  the  first  product  of 
substitution  is  methyl  chlorid,  CH3C1;  the  second  monochlormethyl 
chlorid,  CH2C1.C1;  the  third  dichlormethyl  chlorid,  or  chloroform, 
CHC12.C1;  and  the  fourth  carbon  tetrachlorid,  CC14. 

Similar  derivatives  are  formed  with  Br  and  I,  and  with  the  other 
hydrocarbons  of  the  series. 

Nascent  hydrogen  reduces  all  of  the  halogen  derivatives  to  the 
parent  hydrocarbon:  CHC13+3H2=CH4+3HC1. 

Caustic  potash  or  soda  in  alcoholic  solution  splits  off  the  halogen 
and  water,  with  formation  of  an  unsaturated  hydrocarbon:  CH3.CH2Br 
+KHO=CH2:CH2-hKBr+H2O.  Heated  with  aqueous  potash  the 
haloid  esters  produce  the  corresponding  alcohols:  CH3.CH2Br-fKHO 
=CH3.CH2OH+KBr.  Heated  with  alcoholic  solution  of  potassium 
cyanid  at  100°,  the  haloid  esters  produce  the  alkyl  cyanids:  CH3.CH2I 
+KCN=CH3.CH2.CN+KI.  (p. 340).  They  also  combine  with  am- 
monia to  form  amins  (p.  327) :  CH3C1+NH3=CH3.NH3.C1. 

Methyl  Chlorid — CH3C1 — 50.5 — is  a  colorless  gas,  slightly  soluble 
in  H2O,  and  having  a  sweetish  taste  and  odor.  It  is  prepared  com- 
mercially by  heating  trimethylammonium  chlorid  (obtained  by  dis- 
tilling beet  sugar  molasses):  3N(CH3)3HC1=2CH3C1+2N(CH3)3+ 
NH2CH3+HC1.  It  may  be  condensed  to  a  liquid  which  boils  at  —22° 
( — 7.6°  F.),  in  which  form  it  is  used  in  ice  machines,  as  a  spray  in 
neuralgia,  and  as  an  anaesthetic;  for  the  latter  uses  either  alone  or 
mixed  with  CHCl3,C4HioO,  or  C2H5C1.  It  burns  with  a  greenish 
flame. 

Dichlormethane — Methene  chlorid— Methylene  chlorid — Chloro- 
methyl — Monochlormethyl  chlorid — CH2C12 — 85 — is  obtained  by  the 
action  of  Cl  upon  CH4,  and  by  the  reduction  of  CHC13  by  nascent 
hydrogen. 

It  is  a  colorless,  oily  liquid;  boils  at  40°  (104°  F.);  sp.  gr.  1.36; 
its  odor  is  similar  to  that  of  chloroform ;  it  is  very  slightly  soluble  in 
H2O  and  is  not  inflammable.  It  has  been  used  as  an  anaesthetic,  but 
has  been  discarded  as  being  less  safe  than  chloroform. 


234  MANUAL    OF    CHEMISTRY 

Trichlormethane — Methenyl  chlorid — Formyl  chlorid — Dichlor- 
methyl  chlorid — Chloroform — Chloroformum  (U.  IS.;  Br.) — CHC13 
—120.5 — is  obtained  by  heating  in  a  capacious  still,  35-40  litres  (9-11 
gall.)  of  H2O,  adding  5  kilos  (11  Ibs.)  of  recently  slacked  lime  and 
10  kilos  (22  Ibs.)  of  chlorid  of  lime;  2.5  kilos  (4  qts.)  of  alcohol  are 
then  added  and  the  temperature  quickly  raised  until  the  product 
begins  to  distil,  when  the  fire  is  withdrawn,  heat  being  again  applied 
toward  the  end  of  the  reaction.  The  crude  chloroform  so  obtained  is 
purified,  first  by  agitation  with  H2S04  then  by  mixing  with  alcohol 
and  recently  ignited  potassium  carbonate,  and  distilling  the  mixture. 

Chloroform  is  now  extensively  manufactured  by  the  action  of 
bleaching  powder  upon  acetone,  the  reaction  being  expressed  by  the 
equation  :  2CO(CH3)2  +  6CaCl(OCl)  =  2CHC13  +  2Ca(HO)2  +  (CH3- 
COO)2Ca+3CaCl2. 

It  is  best  obtained  pure  by  heating  chloral  hydrate  with  an  alkali: 
C2HC13(OH)2+KHO=CHC13+HCOOK+H2O. 

It  is  a  colorless,  volatile  liquid,  having  a  strong,  agreeable,  ether- 
eal odor,  and  a  sweet  taste;  sp.  gr.  1.497;  very  sparingly  soluble  in 
H2O;  miscible  with  alcohol  and  ether  in  all  proportions;  boils  at 
60.8°  (141.4°  F.).  It  is  a  good  solvent  for  many  substances  insol- 
uble in  H2O,  such  as  phosphorus,  iodiu,  fats,  resins,  caoutchouc, 
gutta-percha  and  the  alkaloids. 

It  ignites  with  difficulty,  but  burns  from  a  wick  with  a  smoky,  red 
flame,  bordered  with  green.  It  is  not  acted  on  by  H2SO4,  except  after 
long  contact,  when  HC1  is  given  off.  In  direct  sunlight  Cl  converts 
it  into  CCU  and  HC1.  The  alkalies  in  aqueous  solution  do  not  act 
upon  it,  but  when  heated  with  them  in  alcoholic  solution,  it  is  decom- 
posed with  formation  of  chlorid  and  formate  of  the  alkaline  metal. 
When  perfectly  pure  it  is  not  altered  by  exposure  to  light;  but  if  it 
contain  compounds  of  N,  even  in  very  minute  quantity,  it  is  gradu- 
ally decomposed  by  solar  action  into  HC1,  Cl  and  other  substances. 

Impurities. — Alcohol,  if  present  in  large  amount,  lowers  the  sp. 
gr.  of  the  chloroform,  and  causes  it  to  fall  through  H2O  in  opaque, 
pearly  drops.  If  present  in  small  amount  it  produces  a  green  color 
with  ferrous  dinitrosulfid  (obtained  by  acting  on  ferrous  chlorid  with 
a  mixture  of  potassium  nitrate  and  ammonium  hydrosulfid).  Alde- 
hyde produces  a  brown  color  when  CHC13  containing  it  is  heated  with 
liquor  potassa3.  Hydrochloric  acid  reddens  blue  litmus,  and  causes  a 
white  precipitate  in  an  aqueous  solution  of  silver  nitrate  shaken  with 
chloroform.  Methyl  and  empyreumatic  compounds  are  the  most  dan- 
gerous of  the  impurities  of  chloroform.  Their  absence  is  recognized 
by  the  following  characters:  (1)  When  the  chloroform  is  shaken  with 
an  equal  volume  of  colorless  H2SO4,  and  allowed  to  stand  24  hours; 
the  upper  (chloroform)  layer  should  be  perfectly  colorless,  and  the 


HALOID    DERIVATIVES    OP    THE    PARAFFINS  235 

lower  (acid)  layer  colorless  or  faintly  yellow.  (2)  When  a  small 
quantity  is  allowed  to  evaporate  spontaneously,  the  last  portions 
should  have  no  pungent  odor,  and  the  remaining  film  of  moisture 
should  have  no  taste  or  odor  other  than  those  of  chloroform. 

Analytical  Characters. —  (1)  Add  a  little  alcoholic  solution  of 
potash  and  2-3  drops  of  anilin  and  warm :  the  disagreeable  odor  of 
isobenzonitril  (q.  v.)  is  produced.  (2)  Vapor  of  CHCls,  when  passed 
through  a  red-hot  tube,  is  decomposed  with  formation  of  HC1  and 
Cl,  the  former  of  which  is  recognized  by  the  production  of  a  white 
ppt.,  soluble  in  ammonium  hydroxid,  in  an  acid  solution  of  silver 
nitrate.  This  test  does  not  afford  reliable  results  when  the  substance 
tested  contains  a  free  acid  and  chlorids.  (3)  Dissolve  about  0.01  gm. 
of  /8  naphthol  in  a  small  quantity  of  KHO  solution,  warm,  and  add 
the  suspected  liquid;  a  blue  color  is  produced.  (4)  Add  about  0.3 
grm.  resorcinol  in  solution,  and  3  gtts.  NaHO  solution  and  boil 
strongly.  In  the  presence  of  CHCla  a  yellowish -red  color  is  produced, 
and  the  liquid  exhibits  a  beautiful  yellow -green  fluorescence. 

Toxicology. — The  action  of  chloroform  varies  as  it  is  taken  by  the 
stomach  or  by  inhalation.  In  the  former  case,  owing  to  its  insolu- 
bility, but  little  is  absorbed,  and  the  principal  action  is  the  local  irri- 
tation of  the  mucous  surfaces.  Recovery  has  followed  a  dose  of  four 
ounces,  and  death  has  been  caused  by  one  drachm,  taken  into  the 
stomach.  Chloroform  vapor  acts  much  more  energetically,  and  seems 
to  owe  its  potency  for  evil  to  its  paralyzing  influence  upon  the  res- 
piratory nerve  centers,  and  upon  the  cardiac  ganglia.  While  persons 
suffering  from  heart  disease  are  particularly  susceptible  to  the  para- 
lyzing effect  of  chloroform  vapor,  there  are  many  cases  recorded  of 
death  from  the  inhalation  of  small  quantities,  properly  diluted,  in 
which  no  heart  lesion  was  found  upon  a  post-mortem  examination. 
Chloroform  is  apparently  not  altered  in  the  system,  and  is  eliminated 
with  the  expired  air. 

No  chemical  antidote  for  chloroform  is  known.  When  it  has  been 
swallowed,  stomach -lavage  and  emetics  are  indicated;  when  taken 
by  inhalation,  a  free  circulation  of  air  should  be  established  about  the 
face;  artificial  respiration  and  the  application  of  the  induced  current 
to  the  sides  of  the  neck  and  epigastrium  should  be  resorted  to. 

The  nature  of  the  poison  is  usually  revealed  at  the  autopsy  by  its 
peculiar  odor,  which  is  most  noticeable  on  opening  the  cranial  and 
thoracic  cavities.  In  a  toxicological  analysis,  chloroform  is  to  be 
sought  for  especially  in  the  lungs  and  blood.  These  are  placed  in  a 
flask;  if  acid,  neutralized  with  sodium  carbonate,  and  subjected  to 
distillation  at  the  temperature  of  the  water- bath.  The  vapors  are 
passed  through  a  tube  of  difficultly  fusible  glass ;  at  first  the  tube  is 
heated  to  redness  for  about  an  inch  of  its  length,  and  test  No.  2 


236  MANUAL    OF    CHEMISTRY 

applied  to  the  issuing  gas.  The  tube  is  then  allowed  to  cool,  and  the 
distillate  collected  in  a  pointed  tube,  from  the  point  of  which  any 
CHC13  is  removed  by  a  pipette  and  tested  according  to  Nos.  1,  3  and 
4  above. 

Carbon  Tetrachlorid — Chlorocarbon — CCU — 154 — is  formed  by  the 
prolonged  action,  in  sunlight,  of  Cl  upon  CH3C1  or  CHC13;  or  more 
rapidly,  by  passing  Cl,  charged  with  the  vapor  of  carbon  disulfid, 
through  a  red-hot  tube,  and  purifying  the  product. 

It  is  a  colorless,  oily  liquid,  insoluble  in  EbO;  soluble  in  alcohol 
and  in  ether;  sp.  gr.  1.56;  boils  at  78°  (172.4°  F.).  Its  vapor  is 
decomposed  at  a  red  heat  into  a  mixture  of  the  dichlorid,  C2C14,  tri- 
chlorid,  C2C16,  and  free  Cl. 

Methyl  Bromid — CH3Br — 95. — A  colorless  liquid;  sp.  gr.  1.664; 
boils  at  13°  (55.4°  F.);  formed  by  the  combined  action  of  P  and 
Br  on  methyl  hydroxid. 

Tribrommethane — Dibromomethyl  bromid —  Methenyl  bromid — 
Formyl  bromid — Bromoform — CHBr2.Br — 253 — is  prepared  by  grad- 
ually adding  Br  to  a  cold  solution  of  KHO  in  methyl  alcohol  until 
the  liquid  begins  to  be  colored;  and  rectifying  over  CaCl2. 

A  colorless,  aromatic,  sweet  liquid;  sp.  gr.  2.13;  boils  at  150°- 
152°  (302°-306°  F.) ;  solidifies  at— 9°  (15.8°  F.) ;  sparingly  soluble  in 
EbO;  soluble  in  alcohol  and  ether.  Boiled  with  alcoholic  KHO  it  is 
decomposed  in  the  same  way  as  is  CHCls. 

Its  physiological  action  is  similar  to  that  of  CHCls.  It  occurs  as 
an  impurity  of  commercial  Br,  accompanied  by  carbon  tetrabromid, 
CBr4. 

Methyl  lodid— CH3I— 142— a  colorless  liquid,  sp.  gr.  2.237;  boils 
at  45°  (113°  F.);  burns  with  difficulty,  producing  violet  vapor  of 
iodin.  It  is  prepared  by  a  process  similar  to  that  for  obtaining  the 
bromid,  and  is  used  in  the  anilin  industry. 

Triiodomethane — Dliodometliyl  iodid — Methenyl  iodid  —  Formyl 
iodid — lodoform — lodoformum,  U.  S. —  CHI2I — 394.  —  Formed  like 
CHC13  and  CHBr3,  by  the  combined  action  of  KHO  and  the  halogen 
upon  alcohol;  it  is  also  produced  by  the  action  of  I  upon  a  great 
number  of  organic  substances,  and  is  usually  prepared  by  heating  a 
mixture  of  alkaline  carbonate,  H2O,  I  and  ethylic  alcohol,  and  purify- 
ing the  product  by  recrystallization  from  alcohol.  It  is  also  produced 
from  acetone  by  making  a  solution  containing  50  gm.  KI,  6  gm. 
acetone,  and  2  gm.  NaHO  in  2  L.  H2O  and  gradually  adding  a  dilute 
solution  of  KC103. 

lodoform  is  a  solid,  crystallizing  in  yellow,  hexagonal  plates, 
which  melt  at  20°  (248°  F.).  It  may  be  sublimed,  a  portion  being 
decomposed.  It  is  insoluble  in  water,  acids  arid  alkaline  solutions; 
soluble  in  alcohol,  ether,  carbon  disulfid,  and  the  fatty  and  essential 


OXIDATION    PRODUCTS    OF    THE    PARAFFINS  237 

oils;  the  solutions,  when  exposed  to  the  light,  undergo  decomposition 
and  assume  a  violet-red  color.  It  has  a  sweet  taste,  and  a  peculiar, 
penetrating  odor,  resembling,  when  the  vapor  is  largely  diluted  with 
air,  that  of  saffron.  When  heated  with  potash  a  portion  is  decom- 
posed into  formate  and  iodid,  while  another  portion  is  carried  off 
unaltered  with  the  aqueous  vapor.  It  contains  96.7%  of  its  weight 
of  iodin. 

Ethyl  Chlorid — Hydrochloric  or  muriatic  ether — C2H5C1 — 64.5.— 
A  colorless,  ethereal  liquid;  boils  at  11°  (51.8°  F.);  obtained  by 
passing  gaseous  HC1  through  ethylic  alcohol  to  saturation,  and 
distilling  over  the  water-bath.  It  is  now  used  to  produce  cold  by 
spraying.  The  liquid  and  vapor  are  readily  inflammable. 

By  the  continued  action  of  Cl  in  the  sunshine  upon  ethyl  chlorid, 
or  upon  ethene  chlorid,  C2H4,Cl2,  a  white,  crystalline  solid,  Hexa- 
chlorethane  or  carbon  trichlorid,  C2C16,  is  produced.  It  is  insol- 
uble in  H20,  soluble  in  alcohol  and  in  ether,  has  an  aromatic  odor, 
fuses  at  160°  (320°  F.),  and  boils  at  182°  (359.6°  F.). 

Ethyl  Bromid — Hydrobromic  ether  —  C2HsBr — 109 — A  colorless, 
ethereal  liquid;  boils  at  40.7°  (105.3°  F.)  obtained  by  the  combined 
action  of  P  and  Br  on  ethylic  alcohol.  It  is  now  extensively  used  as 
an  anesthetic  in  minor  surgery. 

Ethyl  Iodid — Hydriodic  ether — C2HsI — 156 — is  prepared  by  placing 
absolute  alcohol  and  P  in  a  vessel  surrounded  by  a  freezing  mixture 
and  gradually  adding  I.  When  the  action  has  ceased,  the  liquid  is 
decanted,  distilled  over  the  water -bath  and  the  distillate  washed  and 
rectified. 

It  is  a  colorless  liquid;  boils  at  72.2°  (162°  F.);  has  a  powerful, 
ethereal  odor;  burns  with  difficulty.  It  is  largely  used  in  the  anilin 
industry. 

[See  also  Esters  of  Glycols,  p.  315.] 


OXIDATION   PRODUCTS   OF   THE  PARAFFINS. 

Five  important  and  distinct  classes  of  compounds  are  derivable 
from  the  saturated  hydrocarbons  by  oxidation  : 

One  of  these  may  be  considered  as  derived  from  the  hydrocarbon 
by  the  insertion  of  an  oxygen  atom  between  two  of  its  hydrocarbon 
groups.  Thus  from  the  hydrocarbon  CHs.CH^CEb.CHa  we  may  de- 
rive the  oxids  CHa.O.CHs.CEb.CHs,  and  CH3.CH2.O.CH2.CH3.  These 
are  the  true  oxids  of  the  hydrocarbon  radicals,  and  are  known  as  the 
simple  ethers.  It  will  be  more  convenient  to  consider  them  after 
having  discussed  the  other  oxidation  products. 

The  other  four  classes  are  more  closely  related  to  each  other. 


238  MANUAL    OF    CHEMISTRY 

They  may  be  considered  as  being  derived  from  the  hydrocarbons  in 
one  of  two  ways;  either 

(1)  By  the  interpolation  or  substitution,  or  both,  of  an  oxygen 
atom  or  atoms  in  one  of  the  groups  CH3,  CEb,  or  CH  of  the  parent 
hydrocarbon  (see  formula  on  p.  230).  Thus: 

(H2 :C.H)' becomes  (H2:C.O.H)';    (O:C.H)'or  (OrC.O.H)' 
(H.C.H)"        "         (H.C.O.H)"or  (C:O)"   and 
(C.H)'"  "         (C.O.H)'" 

and  by  the  oxidation  of  a  single  group  in  the  hydrocarbon:   isopen- 
tane;  (CH3)2:CH.CH2.CH3  the  following  products  may  be  obtained: 


(CH3)2 

(CH3)2 

(CH3)2 

(CH3)2 

(CH3)2 

(CH3)2 

II 

II 

II 

II 

II 

II 

CH 

CH 

CH 

CH 

CH 

C.O.H 

1 

1 

1 

1 

1 

1 

CH2 

CH2 

CH2 

H.  C.O.H 

C:0 

CH2 

1 

1 

1 

1 

1 

1 

H2:C.O.H 

0:C.H 

OrC.O.H 

CH3 

CH3 

CH3 

Primary 

Aldehyde. 

Acid. 

Secondary 

Ketone. 

Tertiary 

Alcohol. 

Alcohol. 

Alcohol. 

Isobutyl 

Valeral- 

Isovaler- 

Methyl 

Methyl 

Dimethyl 

Carbinol. 

dehyde. 

iauic  Acid. 

isopropyl 

isopropyl 

-ethyl 

Carbinol. 

Ketone. 

Carbinol. 

(2)  Or  these  compounds  may  be  considered  as  produced  by  the  sub- 
stitution of  hydroxyls  (OH),  for  one  or  more  of  the  hydrogen  atoms 
of  the  hydrocarbon,  it  being  remembered  that  when  a  substance  is  thus 
produced  in  which  two  hydroxyls  are  attached  to  the  same  carbon 
atom,  water  separates,  except  under  the  circumstances  referred  to  on 
page  225.  Thus  from  the  hydrocarbon :  propane,  CH3.CH2.CH3,  the 
following  products  may  be  derived  by  substitution  in  a  single  hy- 
drocarbon group  : 

CH3.CH2.C^Q|I=Primary  alcohol; 
CH3.CH2.C^H)2— H2O=CH3.CH2.C<^= Aldehyde; 

CH3.CH2.C:(OH)3  —  H2O=CH3.CH2.C^QH=Acid; 

CH3 .  ( CH .  OH ) .  CH3=  Secondary  alcohol ; 

CH3.(C :  [OH]  2 )  .CH3— H2O=CH3.  (C  :O)  .CH3=Ketone. 

When  the  number  of  hydroxyls  substituted  in  each  hydrocarbon 
group  exceeds  one,  the  number  of  derivatives  increases  rapidly  with 
an  increasing  number  of  C  atoms  in  the  parent  hydrocarbon.  Thus 
the  second  term,  of  the  series,  CH3.CH3,  yields  nine  derivatives  (p. 
225) : 

I.  II.  III. 

CH2OH  CH(OH)2  O:C.H  C(OH)3  O:C.OH 

|    '  I  -H20=       |  |  -H20=       I 

CH3  CH3  CH3  CH3  CH3 

Ethylic  Acetic  Acetic 

Alcohol.  Aldehyde.  Acid. 


ALCOHOLS— HYDROCARBON    HYDROXIDS  239 

IV.  V.  VI. 

CH2OH  CH(OH)2  0:C.H  CH(OH)2  O:C  H 

— H2O=        |  |  — 2H20=      I  ' 

CH2OH  CH2OH  H2:C.OH  CH(OH)2  O:C.H 

Ethylene  Glycolyl  Glyoxal 

Glycol.  Aldehyde. 

VII.  VIII.  IX. 

C(OH)3  O:C.OH 

C(OH)3  0:C.OH  -H2O=       I  C(OH)3  O:C  OH 

— H2O=  |  PTT/OTTN  rrA  /OH          |  — 2H2O=          I 

CH2OH  H2:C.OH  '  \OH      C(OH)3  OrC.OH 

Glycollie  Glyoxylic  Oxalic 

Acid.  Acid  Acid. 

There  are  twenty -nine  possible  derivatives  of  the  third  hydro- 
carbon, CH3.CH2.CH3. 

The  four  classes  of  oxidation  products  under  consideration  are 
therefore  : 

A.  The  alcohols,  subdivided   into  (a)  Primary,  containing   the 
group— C<^o^;  (5)  Secondary,  containing  the  group  =C\OH »  and  (c) 
Tertiary,  containing  the  group^C.OH; 

B.  The  aldehydes,  containing  the  group—  V\S-, 

C.  The  ketones,  containing  the  group=C=0;  and 

D.  The  carboxylic  acids,  containing  the  group  carboxyl :  ~~C\OH' 


ALCOHOLS—  HYDROCARBON  HYDROXIDS. 

These  substances  are  mainly  characterized  by  their  power  of 
entering  into  double  decomposition  with  acids  to  form  neutral  com- 
pounds, called  esters,  water  being  at  the  same  time  formed  at  the 
expense  of  both  alcohol  and  acid.  They  are  the  hydroxids  of  hy- 
drocarbon radicals,  the  alkyls,  and  as  such  resemble  the  metallic 
hydroxids,  while  the  esters  are  the  counterparts  of  the  metallic 
salts  : 


Ethyl  hydroxid.      Acetic  acid.       Ethyl  acetate.    Water. 


Potassium    Acetic  acid.  Potassium         Water. 

hydroxid.  acetate. 

Or  they  may  be  regarded  as  substances  derived  from  the  hydro- 
carbons by  the  substitution  of  one  or  more  hydroxyls  for  one  or  more 
hydrogen  atoms.  Alcohols  containing  one  OH  are  designated  as 
monoatomic  or  monohydric  ;  those  containing  two  OH  groups  are 
diatomic  or  dihydric,  etc.: 


238  MANUAL    OF    CHEMISTRY 

They  may  be  considered  as  being  derived  from  the  hydrocarbons  in 
one  of  two  ways;  either 

(1)  By  the  interpolation  or  substitution,  or  both,  of  an  oxygen 
atom  or  atoms  in  one  of  the  groups  CH3,  CEb,  or  CH  of  the  parent 
hydrocarbon  (see  formulae  on  p.  230).     Thus: 

(H2  :C.H)'  becomes  (H2:C.O.H)';    (O:C.H)'or  (O:C.O.H)' 
(H.C.H)"        "         (H.C.O.H)"or  (C:O)"  and 
(C.H)"'  "         (C.O.H)'" 

and  by  the  oxidation  of  a  single  group  in  the  hydrocarbon:   isopen- 
tane;  (CHahiCH.CH^.CHa  the  following  products  may  be  obtained: 

(CH3)2  (CH3)2       (CH3)2  (CH3)2  (CH3)2  (CH3)2 

II  II  II  II  II  || 

C.O.H 

CH2 
I 
CH3 

Tertiary 
Alcohol. 
Dimethyl 
-  ethyl 
Carbinol. 

(2)  Or  these  compounds  may  be  considered  as  produced  by  the  sub- 
stitution of  hydroxyls  (OH),  for  one  or  more  of  the  hydrogen  atoms 
of  the  hydrocarbon,  it  being  remembered  that  when  a  substance  is  thus 
produced  in  which  two  hydroxyls  are  attached  to  the  same  carbon 
atom,  water  separates,  except  under  the  circumstances  referred  to  on 
page  225.     Thus  from  the  hydrocarbon:  propane,  CH3.CH2.CH3,  the 
following  products  may  be  derived  by  substitution  in  a  single  hy- 
drocarbon group  : 

CH3.CH2.C^Q|j=Primary  alcohol; 

2—  H2O=CH3.CH2.C^Q=Aldehyde; 


CH 

CH 

CH 

CH 

CH 

1 

1 

1 

1 

1 

CH2 

CH2 

CH2 

H.C.O.H 

C:0 

1 

1 

1 

1 

1 

H2:C.O.H 

O:C.H 

0:C.O.H 

CH3 

CH3 

Primary 

Aldehyde. 

Acid. 

Secondary 

Ketone. 

Alcohol. 

Alcohol. 

Isobutyl 

Valeral- 

Isovaler- 

Methyl 

Methyl 

Carbinol. 

dehyde. 

ianic  Acid. 

isopropyl 

isopropyl 

Carbinol. 

Ketone. 

CH3.CH2.C:(OH)3  —  H2O=CH3.CH2.C^JH=Acid; 
CH3  .  (  CH  .  OH  )  .  CH3=  Secondary  alcohol  ; 
CH3.(C:[OH]2).CH3—  H20=CH3.(C:0).CH3=Ketone. 

When  the  number  of  hydroxyls  substituted  in  each  hydrocarbon 
group  exceeds  one,  the  number  of  derivatives  increases  rapidly  with 
an  increasing  number  of  C  atoms  in  the  parent  hydrocarbon.  Thus 
the  second  term,  of  the  series,  CHa.CHs,  yields  nine  derivatives  (p. 
225): 

I.  n.  III. 

CH2OH  CH(OH)2  0:C.H  C(OH)3  0:C.OH 

-H20=       |  |  -H20=       I 

CH3  CH3  CH3  CH3  CH3 

Ethylic  Acetic  Acetic 

Alcohol.  Aldehyde.  Acid. 


ALCOHOLS— HYDROCARBON    HYDROXIDS  239 

IV.  V.  VI. 

CH2OH  CH(OH)2  O:C.H  CH(OH)2  O-C  H 

— H20=        |  |  — 2H20=      I 

CH2OH  CH2OH  H2:C.OH         CH(OH)2  O:C.H 

Ethylene  Glycolyl  Glyoxal 

Glycol.  Aldehyde. 

VII.  VIII.  IX. 

C(OH)3  O:C.OH 

C(OH)3                 0:C.OH  I           _H2O=       I  C(OH)3                  O:C.OH 

|           — H20=        |  rmom              Tir/OH  I          — 2H20=       | 

CH2OH                H2:C.OH  '  \OH  C(OH)3                 O:C.OH 

Glycollie  Glyoxylie  Oxalic 

Acid.  Acid  Acid. 

There  are  twenty -nine  possible  derivatives  of  the  third  hydro- 
carbon, CH3.CH2.CH3. 

The  four  classes  of  oxidation  products  under  consideration  are 
therefore  : 

A.  The  alcohols,  subdivided   into  (a)  Primary,  containing   the 
group— C^HH;  (&)  Secondary,  containing  the  group  =C\OH 5  an(*  (c) 
Tertiary,  containing  the  group^C.OH; 

B.  The  aldehydes,  containing  the  group— 

C.  The  ketones,  containing  the  group=C=O;  and 

D.  The  carboxylic  acids,  containing  the  group  carboxyl :  — C\OH* 


ALCOHOLS—  HYDROCARBON  HYDROXIDS. 

These  substances  are  mainly  characterized  by  their  power  of 
entering  into  double  decomposition  with  acids  to  form  neutral  com- 
pounds, called  esters,  water  being  at  the  same  time  formed  at  the 
expense  of  both  alcohol  and  acid.  They  are  the  hydroxids  of  hy- 
drocarbon radicals,  the  alkyls,  and  as  such  resemble  the  metallic 
hydroxids,  while  the  esters  are  the  counterparts  of  the  metallic 
salts  : 

(C2H5^  \  0  ,  (C2H30)  \  0_(C2H30)  \  0  .  H  1  0 

H     }C  H  f  C    -    (C2H5)/0-f"H/0 

Ethyl  hydroxid.      Acetic  acid.       Ethyl  acetate.    Water. 


o+    *         0=    *'      o+      o 

Potassium    Acetic  acid.  Potassium         Water. 

hydroxid.  acetate. 

Or  they  may  be  regarded  as  substances  derived  from  the  hydro- 
carbons by  the  substitution  of  one  or  more  hydroxyls  for  one  or  more 
hydrogen  atoms.  Alcohols  containing  one  OH  are  designated  as 
monoatomic  or  monohydric  ;  those  containing  two  OH  groups  are 
diatomic  or  dihydric,  etc.: 


242  MANUAL    OF    CHEMISTRY 

alcoholic  odor,  and  a  sharp,  burning  taste;  sp.  gr.  0.814  at  0°;  boils 
at  66.5°  (151.7°  F.);  burns  with  a  pale  flame,  giving  less  heat  than 
that  of  ethylic  alcohol;  mixes  with  water,  alcohol,  and  ether  in  all 
proportions;  is  a  good  solvent  of  resinous  substances,  and  also  dis- 
solves sulfur,  phosphorus,  potash,  and  soda. 

Methyl  hydroxid  is  not  affected  by  exposure  to  air  under  ordinary 
circumstances,  but  in  the  presence  of  platinum -black  it  is  oxidized, 
with  formation  of  the  corresponding  aldehyde,  formaldehyde,  and 
acid,  formic  acid.  Hot  HNOs  decomposes  it  with  formation  of 
nitrous  fumes,  formic  acid  and  methyl  nitrate.  It  is  acted  upon  by 
H2SO4  in  the  same  way  as  ethyl  alcohol.  The  organic  acids  form 
methyl  esters  with  it.  With  HC1  under  the  influence  of  a  galvanic 
current,  it  forms  an  oily  substance  having  the  composition  C2H3- 
OC1. 

Methylated  spirit  is  ethyl  alcohol  containing  one -ninth  its  vol- 
ume of  wood  spirit. 

Ethyl  Hydroxid — Ethylic  alcohol — Methyl  carbinol — Vinic  alco- 
hol—Alcohol— Spirits  of  wine— CH3.CH2OH— 46. 

Preparation. — Industrially  alcohol  and  alcoholic  liquids  are  ob- 
tained from  substances  rich  in  starch  or  glucose. 

The  manufacture  of  alcohol  consists  of  three  distinct  processes: 
(1)  the  conversion  of  starch  into  sugar;  (2)  the  fermentation  of  the 
saccharine  liquid;  (3)  the  separation,  by  distillation,  of  the  alcohol 
formed  by  fermentation. 

The  raw  materials  for  the  first  process  are  malt  and  some  sub- 
stance (grain,  potatoes,  rice,  corn,  etc.)  containing  starch.  Malt  is 
barley  which  has  been  allowed  to  germinate,  and,  at  the  proper  stage 
of  germination,  roasted.  During  this  growth  there  is  developed  in 
the  barley  a  peculiar  nitrogenous  principle  called  diastase.  The 
starchy  material  is  mixed  with  a  suitable  quantity  of  malt  and 
water,  and  the  mass  maintained  at  a  temperature  of  65°-70° 
(149°-158°  F.)  for  two  to  three  hours,  during  which  the  diastase 
rapidly  converts  the  starch  into  dextrin,  and  this  in  turn  into  mal- 
tose and  glucose. 

The  saccharine  fluid,  or  wort,  obtained  in  the  first  process,  is 
drawn  off,  cooled,  and  yeast  is  added.  As  a  result  of  the  growth  of 
the  yeast -plant,  a  complicated  series  of  chemical  changes  take  place, 
the  principal  one  of  which  is  the  splitting  up  of  the  glucose  into 
carbon  dioxid  and  alcohol :  C6Hi2O6=2C2H5OH-|-2CO2.  There  are 
formed  at  the  same  time  small  quantities  of  glycerol,  succinic  acid, 
and  propylic,  butylic,  and  amylic  alcohols. 

An  aqueous  fluid  is  thus  obtained  which  contains  3-15  per  cent  of 
alcohol.  This  is  then  separated  by  the  third  process,  that  of  distil- 
lation and  rectification.  The  apparatus  used  for  this  purpose  has 


ALCOHOLS  —  HYDROCARBON    HYDROXIDS  243 

been  so  far  perfected  that  by  a  single  distillation  an  alcohol  of  90-95 
per  cent,  can  be  obtained. 

In  some  cases  alcohol  is  prepared  from  fluids  rich  in  glucose,  such 
as  grape  juice,  molasses,  syrup,  etc.  In  such  cases  the  first  process 
becomes  unnecessary. 

Commercial  alcohol  always  contains  IbO,  and  when  pure  or 
absolute  alcohol  is  required,  the  commercial  product  must  be  mixed 
with  some  hygroscopic  solid  substance,  such  as  quicklime,  from 
which  it  is  distilled  after  having  remained  in  contact  twenty-four 
hours. 

Fermentation. — This  term  (derived  from  fervere  =  to  boil)  was 
originally  applied  to  alcoholic  fermentation,  by  reason  of  the  bub- 
bling of  the  saccharine  liquid  caused  by  the  escape  of  €62;  subse- 
quently it  came  to  be  applied  to  all  decompositions  similarly  attended 
by  the  escape  of  gas. 

At  present  it  is  used  by  many  authors  to  apply  to  a  number  of 
heterogeneous  processes ;  and  some  writers  distinguish  between  "  true" 
and  "false"  fermentation.  It  is  best,  we  believe,  to  limit  the  appli- 
cation of  the  term  to  those  decompositions  designated  as  true  fer- 
mentations. 

Fermentation  is  a  decomposition  of  ah  organic  substance,  pro- 
duced by  the  processes  of  nutrition  of  a  low  form  of  animal  or 
vegetable  life. 

The  true  ferments  are  therefore  all  organized  beings,  such  as 
torula  cerevislcB,  producing  alcoholic  fermentation  ;  penicillium  glau- 
cum,  producing  lactic  acid  fermentation;  and  mycoderma  aceti,  pro- 
ducing acetic  acid  fermentation. 

The  false  fermentations  are  not  produced  by  an  organized  body, 
but  by  a  soluble,  unorganized,  nitrogenous  substance,  whose  method 
of  action  is  as  yet  imperfectly  understood.  The  unorganized  fer- 
ments, such  as  diastase,  pepsin,  etc.,  are  called  enzymes. 

An  interesting  total  synthesis  of  alcohol  is  from  calcium  carbid, 
water  and  hydrogen.  Acetylene  is  formed  by  the  action  of  water 
upon  calcium  carbid,  CaC2  +  2H2O  =  CaH2O2  +  C2H2 ;  vapors  of 
acetylene  and  water,  heated  together  to  325°  (617°  F.)  unite  to  form 
aldehyde,  C2H2+H2O==CHO.CH3 ;  and  nascent  hydrogen  converts 
aldehyde  into  alcohol,  CHO.CH3+H2=CH2OH.CH3. 

Properties. — Alcohol  is  a  thin,  colorless,  transparent  liquid,  hav- 
ing a  spirituous  odor  and  a  sharp,  burning  taste;  sp.  gr.  0.8095  at 
0°,  0.7939  at  15°  (59°  F.);  it  boils  at  78.5°  (173.3°  F.),  and  solidi- 
fies at  —130.5°  (—202.9°  F. ) .  At  temperatures  below  —90°  (—130° 
F.)  it  is  viscous.  It  mixes  with  water  in  all  proportions,  the  union 
being  attended  by  elevation  in  temperature  and  contraction  in  volume 
(after  cooling  to  the  original  temperature).  It  also  attracts  moisture 


244  MANUAL    OF    CHEMISTRY 

from  the  air  to  such  a  degree  that  absolute  alcohol  only  remains  such 
for  a  very  short  time  after  its  preparation.  It  is  to  this  power  of 
attracting  H2O  that  alcohol  owes  its  preservative  power  for  animal 
substances.  It  is  a  very  useful  solvent,  dissolving  a  number  of  gases, 
many  mineral  and  organic  acids  and  alkalies,  most  of  the  chlorids 
and  carbonates,  some  of  the  nitrates,  and  the  essences  and  resins. 
The  sulfates  are  insoluble  in  alcohol.  Alcoholic  solutions  of  fixed 
medicinal  substances  are  called  tinctures  ;  those  of  volatile  principles, 
spirits. 

The  action  of  oxygen  upon  alcohol  varies  according  to  the  con- 
ditions. Under  the  influence  of  energetic  oxidants,  such  as  chromic 
acid,  or,  when  alcohol  is  burned  in  the  air,  the  oxidation  is  rapid 
and  complete,  and  is  attended  by  the  extrication  of  much  heat,  and 
the  formation  of  carbon  dioxid  and  water :  C2HeO+ 302=2002+ 
3H2O.  Mixtures  of  air  and  vapor  of  alcohol  explode  upon  contact 
with  flame.  If  a  less  active  oxidant  be  used,  such  as  platinum -black, 
or  by  the  action  of  atmospheric  oxygen  at  low  temperatures,  a  simple 
oxidation  of  the  alcoholic  radical  takes  place,  with  formation  of  acetic 
acid:  CH3.CH2OH  +  O2  =  CH3.COOH+H20,  a  reaction  which  is 
utilized  in  the  manufacture  of  acetic  acid  and  vinegar.  If  the  oxida- 
tion be  still  further  limited,  aldehyde  is  formed  :  2CH3.CH2OH  + 
O2=2CH3.CHO+2H2O.  If  vapor  of  alcohol  be  passed  through  a 
tube  filled  with  platinum  sponge  and  heated  to  redness,  or  if  a  coil 
of  heated  platinum  wire  be  introduced  into  an  atmosphere  of  alcohol 
vapor,  the  products  of  oxidation  are  quite  numerous:  among  them  are 
water,  ethylene,  aldehyde,  acetylene,  carbon  monoxid,  and  acetal. 
Heated  platinum  wire  introduced  into  vapor  of  alcohol  continues  to 
glow  by  the  heat  resulting  from  the  oxidation,  a  fact  which  has 
been  utilized  in  the  thermocautery. 

Chlorin  and  bromin  act  energetically  upon  alcohol,  producing  a 
number  of  chlorinated  and  brominated  derivatives,  the  final  products 
being  chloral  and  bromal  (p.  258).  If  the  action  of  Cl  be  moderated, 
aldehyde  and  HC1  are  first  produced.  lodin  acts  quite  slowly  in  the 
cold,  but  old  solutions  of  I  in  alcohol  (Tr.  iodin.)  are  found  to  contain 
HI,  ethyl  iodid,  and  other  imperfectly  studied  products.  In  the 
presence  of  an  alkali,  I  acts  upon  alcohol  to  produce  iodoform.  Po- 
tassium and  sodium  dissolve  in  alcohol  with  evolution  of  H;  upon 
cooling,  a  white  solid  crystallizes,  which  is  the  double  oxid  of  ethyl 
and  the  alkali  metal,  and  is  known  as  potassium  or  sodium  ethylate 
or  alcoholate.  Nitric  acid,  aided  by  a  gentle  heat,  acts  violently 
upon  alcohol,  producing  nitrous  ether,  brown  fumes,  and  products  of 
oxidation.  (For  the  action  of  other  acids  upon  alcohol  see  the  cor- 
responding esters  and  the  ethers.)  The  hydroxids  of  the  alkali 
metals  dissolve  in  alcohol,  but  react  upon  it  slowly;  the  solution  turns 


ALCOHOLS  — HYDEOCAEBON    HYDEOXIDS  245 

brown  and  contains  an  acetate.  If  alcohol  be  gently  heated  with 
HNOs  and  nitrate  of  silver  or  of  mercury,  a  gray  precipitate  falls, 
which  is  silver  or  mercury  fulminate. 

Varieties. — It  occurs  in  different  degrees  of  concentration:  abso- 
lute alcohol  is  pure  alcohol,  C2H6O.  It  is  not  purchasable,  and  must 
be  made  as  required.  The  so-called  absolute  alcohol  of  the  shops  is 
rarely  stronger  than  98  per  cent.  Alcohol  (U.  S.),  sp.  gr.  0.820, 
contains  94  per  cent,  by  volume,  and  spiritus  rectificatus  (Br.),  sp. 
gr.  0.838,  contains  84  per  cent.  This  is  the  ordinary  rectified  spirit 
used  in  the  arts.  Alcohol  dilutum  (U.  S.)  = Spiritus  tenuior  (Br.), 
sp.  gr.  0.920,  used  in  the  preparation  of  tinctures,  contains  53  per  cent. 
It  is  of  about  the  same  strength  as  the  proof  spirit  of  commerce. 

Analytical  Characters. — (1)  Heated  with  a  small  quantity  of  solu- 
tion of  potassium  dichromate  and  EbSC^,  the  liquid  assumes  an 
emerald -green  color,  and,  if  the  quantity  of  C2HeO  be  not  very 
small,  the  peculiar  fruity  odor  of  aldehyde  is  developed.  (2)  Warmed 
and  treated  with  a  few  drops  of  potash  solution  and  a  small  quantity 
of  iodin,  an  alcoholic  liquid  deposits  a  yellow,  crystalline  ppt.  of 
iodoform,  either  immediately  or  after  a  time.  (3)  If  HNOs  be  added 
to  a  liquid  containing  C2H6O,  nitrous  ether,  recognizable  by  its  odor, 
is  given  off.  If  a  solution  of  mercurous  nitrate  with  excess  of  HNOa 
be  then  added,  and  the  mixture  heated,  a  further  evolution  of  nitrous 
ether  occurs,  and  a  yellow- gray  deposit  of  fulminating  mercury  is 
formed,  which  may  be  collected,  washed,  dried,  and  exploded.  (4) 
If  an  alcoholic  liquid  be  heated  for  a  few  moments  with  H2S04  diluted 
with  H2O  and  distilled,  the  distillate,  on  treatment  with  EySO*  and 
potassium  permanganate,  and  afterward  with  sodium  thiosulfate, 
yields  aldehyde,  which  may  be  recognized  by  the  production  of  a  vio- 
let color  with  a  dilute  solution  of  fuchsin. 

None  of  the  above  reactions,  taken  singly,  is  characteristic  of 
alcohol. 

Alcohol  is  determined  quantitatively  in  simple  mixtures  of  alcohol 
and  water  by  determining  the  specific  gravity  and  referring  to  tables 
constructed  for  the  purpose.  In  alcoholic  beverages  100  cc.  of  the 
sample  is  distilled  until  75  cc.  have  passed  over,  the  distillate  is  then 
made  up  to  100  cc.  with  water,  and  the  sp.  gr.  determined. 

Alcoholic  Beverages. — These  may  be  divided  into  four  classes: 

I. — Those  prepared  by  the  fermentation  of  malted  grain — beers, 
ales  and  porters. 

II. — Those  prepared  by  the  fermentation  of  grape  juice — wines. 

III. — Those  prepared  by  the  fermentation  of  the  juices  of  fruits 
other  than  the  grape — cider,  fruit-wines. 

IV. — Those  prepared  by  the  distillation  of  some  fermented  sac- 
charine liquid — ardent  spirits. 


246  MANUAL    OF    CHEMISTRY 

Beer,  ale  and  porter  are  aqueous  infusions  or  decoctions  of  malted 
grain,  fermented  and  flavored  with  hops.  They  contain,  therefore, 
the  soluble  constituents  of  the  grain  employed;  dextrin,  maltose  and 
glucose,  produced  during  the  malting;  alcohol  and  carbon  dioxid, 
produced  during  the  fermentation;  and  the  soluble  constituents  of 
the  flavoring  material.  The  alcoholic  strength  of  malt  liquors  varies 
from  1.5  to  9  per  cent,  absolute  alcohol  by  weight.  Weiss-beer  con- 
tains 1.5-1.9  per  cent.;  lager,  4.1-4.5  per  cent.;  bock-beer,  3.88-5.23 
per  cent. ;  London  porter,  5.4-6.9  per  cent. ;  Burton  ale,  5.9  per  cent. ; 
Scotch  ale,  8.5-9  per  cent.  Malt  liquors  all  contain  a  considerable 
quantity  of  nitrogenous  material  (0.4-1  per  cent.  N),  and  succinic, 
lactic  and  acetic  acids.  The  amount  of  inorganic  material,  in  which 
the  phosphates  of  potassium,  sodium  and  magnesium  predominate 
largely,  varies  from  0.2  to  0.3  per  cent.  The  sp.  gr.  is  from  1.014  to 
1.033. 

The  adulterations  of  malt  liquors  are  numerous  and  varied.  So- 
dium carbonate  is  added  with  the  double  purpose  of  neutralizing  an 
excess  of  acetic  acid  and  increasing  the  foam.  The  most  serious 
adulteration  consists  in  the  use  of  artificial  glucose  as  a  substitute  for 
malt,  and,  more  rarely,  in  the  introduction  of  bitter  principles  other 
than  hops,  and  notably  of  strychnin,  cocculus  indicus  (picro toxin), 
and  picric  acid. 

Wines  are  produced  by  the  fermentation  of  grape  juice.  In  the 
case  of  red  wines  the  marc,  or  mass  of  skins,  seed  and  stems,  is 
allowed  to  remain  in  contact  with  the  must,  or  fermenting  juice, 
until,  by  production  of  alcohol,  the  liquid  dissolves  a  portion  of  the 
coloring  matter  of  the  skins.  A  certain  proportion  of  tannin  is  also 
dissolved,  whose  presence  is  necessary  to  prevent  slringiness.  Sweet 
wines  are  produced  from  must  rich  in  glucose,  and  by  arresting  the 
fermentation  before  that  sugar  has  been  completely  decomposed.  Dry 
wines  are  obtained  by  more  complete  fermentation  of  must  less  rich 
in  glucose.  Tartaric  acid  is  the  predominating  acid  in  grape  juice, 
and,  as  the  proportion  of  alcohol  increases  during  fermentation,  the 
acid  potassium  tartrate  is  deposited. 

Most  wines  of  good  quality  improve  in  flavor  with  age,  and  this 
improvement  is  greatly  hastened  by  the  process  of  pasteuring,  which 
consists  in  warming  the  wine  to  a  temperature  of  60°  C.  (140°  F.), 
without  contact  of  air. 

Light  wines  are  those  whose  percentage  of  alcohol  is  less  than  12 
per  cent.  In  this  class  are  included  the  clarets,  Sauternes,  Rhine  and 
Moselle  wines;  champagnes,  Burgundies,  the  American  wines  (except 
some  varieties  of  California  wine),  Australian,  Greek,  Hungarian  and 
Italian  wines. 

The  champagnes  and  some  Moselle  wines  are  sparkling,  a  quality 


ALCOHOLS  — HYDROCARBON    HYDROXIDS  247 

which  is  communicated  to  them  by  carbon  dioxid  produced  by  a 
secondary  fermentation  set  up  in  the  bottled  wine,  and  held  in  solu- 
tion by  its  own  pressure. 

Of  the  still  wines  the  most  widely  used  are  the  clarets,  Vinum 
rubrum  (U.  S.),  or  red  Bordeaux  wines,  and  the  hocks,  Vinum  album 
(U.  S),  or  white  Rhine,  Moselle  and  American  wines.  The  former 
are  of  low  alcoholic  strength,  mildly  astringent,  and  contain  but  a 
small  quantity  of  nitrogenous  material.  The  Rhine  wines  are  thinner 
and  more  acid,  and  generally  of  lower  alcoholic  strength  than  the 
clarets.  The  Burgundy  and  Rhone  wines  are  celebrated  for  their  high 
flavor  and  body;  they  are  not  strongly  alcoholic,  but  contain  a  large 
quantity  of  nitrogenous  material.  Our  native  American  wines,  par- 
ticularly those  of  the  Ohio  valley  and  of  California,  are  yearly  improv- 
ing in  flavor  and  quality.  They  more  closely  resemble  the  Rhine  wines, 
clarets  and  Sauternes  than  other  European  wines. 

Heavy  wines  are  those  whose  alcoholic  strength  is  greater  than 
12  percent.,  usually  14  to  25  per  cent.;  they  include  the  sherries, 
ports,  Madeiras,  Marsala,  and  some  California  wines,  and  are  all  the 
products  of  warm  climates.  Sherry  is  an  amber-colored  wine,  grown 
in  the  south  of  Spain,  Vinum  Xericum  (Br.);  Marsala  closely  re- 
sembles sherry  in  appearance,  and  is  frequently  substituted  for  it. 
Port  is  a  rich,  dark -red  wine,  grown  in  Portugal. 

The  adulteration  of  wine  by  the  addition  of  foreign  substances  is 
confined  almost  entirely  to  their  artificial  coloration,  which  is  pro- 
duced by  the  most  varied  substances,  indigo,  logwood,  fuchsin,  etc. 
The  addition  of  natural  constituents  of  wines,  obtained  from  other 
sources,  and  the  mixing  of  different  grades  of  wine  are,  however, 
extensively  practiced.  Water  and  alcohol  are  the  chief  substances  so 
added;  and  excess  of  the  former  may  be  detected  by  the  taste  and  the 
low  sp.  gr.  after  expulsion  of  the  alcohol.  Most  wines  intended  for 
export  are  fortified  by  the  addition  of  alcohol.  When  the  alcoholic 
spirit  used  is  free  from  amyl  alcohol,  and  is  added  in  moderate  quan- 
tities, there  can  be  no  serious  objection  to  the  practice,  especially  when 
applied  to  certain  wines  which,  without  such  treatment,  do  not  bear 
transportation.  The  mixing  of  fine  grades  of  wine  with  those  of  a 
poorer  quality  is  extensively  practiced,  particularly  with  sherries, 
champagnes,  clarets  and  Burgundies,  and  is  perfectly  legitimate. 
The  same  cannot  be  said,  however,  of  the  manufacture  of  factitious 
wine,  either  entirely  from  materials  not  produced  from  the  grape,  or 
by  converting  white  into  red  wines,  or  by  mixing  wines  with  coloring 
matters,  alcohol,  etc.,  to  produce  imitations  of  wines  of  a  different 
class,  an  industry  which  flourishes  extensively  in  Normandy,  at  Bin- 
gen  on  the  Rhine,  and  at  Hamburg.  The  wines  so  produced  are 
usually  heavy  wines,  port  and  sherry,  so  called. 


248  MANUAL    OF    CHEMISTRY 

Cider  is  the  fermented  juice  of  the  apple,  prepared  very  much  in 
the  same  way  as  wine  is  from  grape  juice,  and  containing  from  3.5  to 
7.5  per  cent,  of  alcohol.  It  is  very  prone  to  acetous  fermentation, 
which  renders  it  sour  and  not  only  unpalatable  but  liable  to  produce 
colic  and  diarrhoea  with  those  not  hardened  to  its  use. 

Spirits  are  alcoholic  beverages,  prepared  by  fermentation  and  dis- 
tillation. They  differ  from  beers  and  wines  in  containing  a  greater 
proportion  of  alcohol  (35  to  50  per  cent.),  and  in  not  containing  any 
of  the  non- volatile  constituents  of  the  grains  or  fruits  from  which  they 
are  prepared.  Besides  alcohol  and  water  they  contain  acetic,  butyric, 
valerianic  and  cenanthic  esters,  to  which  they  owe  their  flavor;  some- 
times tannin  and  coloring  matter  derived  from  the  cask;  amylic  and 
other  higher  alcohols;  sugar  intentionally  added,  and  caramel. 

The  varieties  of  spirituous  beverages  in  common  use  are:  Brandy, 
spiritus  vini  gallici  (U.  S.,  Br.),  obtained  by  the  distillation  of 
wine,  and  manufactured  in  France  and  in  California  and  Ohio.  It  is 
of  sp.  gr.  0.929  to  0.934,  is  dark  or  light  in  color,  according  to  the 
quantity  of  burnt  sugar  added,  and  contains  about  1.2  per  cent,  of 
solid  matter.  American  whisky,  spiritus  frumenti  (U.  S.),  pre- 
pared from  wheat,  rye,  barley,  or  Indian  corn;  has  a  sp.  gr.  of  0.922 
to  0.937  and  contains  0.1  to  0.3  percent,  of  solids.  Scotch  and  Irish 
whiskies,  colorless  spiritis  distilled  from  fermented  grains;  sp.  gr. 
0.915  to  0.920,  having  a  peculiar  smoky  flavor  produced  by  drying 
the  malted  grain  by  a  peat  fire.  Gin,  also  distilled  from  malted 
grain,  sp.  gr.  0.930  to  0.944,  flavored  with  juniper,  and  sometimes 
fraudulently  with  turpentine.  Rum,  a  spirit  distilled  from  molasses, 
and  varying  in  color  and  flavor  from  the  dark  Jamaica  rum  to  the 
colorless  St.  Croix  rum.  The  former  is  of  sp.  gr.  0.914  to  0.926,  and 
contains  one  per  cent,  of  solid  matter.  Brandy,  whisky,  etc.,  owe 
their  color  to  a  pigment  formed  by  charring  the  interior  of  the  white- 
oak  casks. 

Liqueurs  or  cordials  are  spirits  sweetened  and  flavored  with  vege- 
table aromatics,  and  frequently  colored;  anisette  is  flavored  with  ani- 
seed; absinthe,  with  wormwood;  curac.oa,  with  orange  peel;  kirsch- 
wasser,  with  cherries,  the  stones  being  cracked  and  the  spirits  dis- 
tilled from  the  bruised  fermented  fruit;  hummel,  with  cummin  and 
caraway  seeds  ;  maraschino,  with  cherries  ;  noyau,  with  peach  and 
apricot  kernels. 

Propyl  Hydroxid — Ethyl  carbinol — Primary  propyl  alcohol — 
CHa.CEb.CIbOH — 60 — is  produced,  along  with  ethylic  alcohol,  dur- 
ing fermentation,  and  obtained  by  fractional  distillation  of  marc 
brandy,  from  cognac  oil,  huile  de  marc  (not  to  be  confounded  with  oil 
of  wine),  an  oily  matter,  possessing  the  flavor  of  inferior  brandy, 
which  separates  from  marc  brandy,  distilled  at  high  temperatures; 


ALCOHOLS  — HYDEOCAEBON    HYDEOXIDS  249 

ind  from  the  residues  of  manufacture  of  alcohol  from  beet -root, 
grain,  molasses,  etc.  It  is  a  colorless  liquid,  has  a  hot  alcoholic 
taste,  and  a  fruity  odor;  boils  at  96.7°  (206.1°F.);  and  is  miscible 
with  water.  It  has  not  been  put  to  any  use  in  the  arts.  Its  intoxi- 
cating and  poisonous  actions  are  greater  than  those  of  ethyl  alcohol 
It  exists  in  small  quantity  in  cider. 

Butyl  Alcohols— CiHoOH— 74.— The  four  butyl  alcohols  theoreti- 
cally possible  are  known  to  exist : 

Propyl  Carbinol — Primary  normal  butyl  alcohol — Butyl  alcohol 
of  fermentation — CHs.CH^.CH^.CEbOH — is  formed  in  small  quan- 
tities during  alcoholic  fermentation,  and  may  be  obtained  by  repeated 
fractional  distillation  from  the  oily  liquid  left  in  the  rectification  of 
vinic  alcohol.  It  is  a  colorless  liquid;  boils  at  116.8°  (245.8°  F.). 
It  is  more  actively  poisonous  than  ethyl  or  methyl  alcohol. 

Isopropyl   Carbinol  —  Isobutyl   alcohol— CH3/CH-CH20H  —oc- 
curs in  the  fusel  oil  obtained  in  the  products  of  fermentation  and 
distillation  of  beet-root  molasses.      It  is  a  colorless  liquid,  sp.  gr 
0.8032;   boils  at  108.4°  (219. 1°F.). 

Ethyl-methyl    Carbinol  —  Secondary   butyl    alcohol  —  Butylene 

hydrate— ^"^^CHOH— a  liquid  which  boils  at  99°  (210.2°  F.). 

CH3\ 

Trimethyl  Carbinol — Tertiary  butyl  alcohol,  CH3— COH— a  crystal - 

CH3/ 

line  solid  which  fuses  at  25°  (77°  F.),  and  boils  at  82°  (179.6°  F.). 

Amylic  Alcohols — C5HnOH — 88. — The  eight  amyl  alcohols  theo- 
retically possible  (see  p.  241)  are  known.  The  substance  usually 
known  as  amylic  alcohol,  potato  spirit,  fusel  oil,  alcohol  amylicum 
(Br.),  is  the  primary  alcohol,  ^ul)  CH-  CH2-  CH2OH,  with  lesser 
quantities  of  other  alcohols,  differing  in  nature  and  amount  with  the 
grain  used,  and  the  conditions  of  the  fermentation  and  distillation, 
each  kind  of  "spirit"  furnishing  and  containing  a  peculiar  fusel. 

In  the  process  of  manufacture  of  ardent  spirits  the  fusel  oil  accu- 
mulates in  great  part  in  the  still,  but  much  of  it  distils  over,  and  is 
more  or  less  completely  removed  from  the  product  by  the  process  of 
defuselation. 

Spirits  properly  freed  of  fusel  oil  give  off  no  irritating  or  foul 
fumes  when  hot.  They  are  not  colored  red  when  mixed  with  three 
parts  C2H6O  and  one  part  strong  EbSO*.  They  are  not  colored  red 
or  black  by  ammoniacal  silver  nitrate  solution.  When  150  parts  of 
the  spirit,  mixed  with  1  part  potash,  dissolved  in  a  little  H2O,  are 
evaporated  down  to  15  parts,  and  mixed  with  an  equal  volume  of 
dilute  H2SO4,  no  offensive  odor  should  be  given  off. 

While  young  spirits  owe  their  rough  taste,  and,  in  great  measure, 
their  intoxicating  qualities  to  the  presence  of  fusel  oil,  it  is  a  popular 


250  MANUAL    OF    CHEMISTRY 

error  that  a  whisky  would  be  improved  by  complete  removal  of  all 
products  except  ethyl  alcohol.  The  improvement  of  a  spirit  by  age 
is  due  to  chemical  changes  in  the  small  amount  of  fusel  retained  in  a 
properly  manufactured  product,  and,  were  this  absent,  the  spirit 
would  deteriorate  rather  than  improve  by  age. 

The  individual  amylic  alcohols  have  the  following  characters  : 
Butyl  carbinol;  normal  amylic  alcohol,— CH3.CH2.CH2.CH2.CH2OH 
—is  a  colorless  liquid,  boils  at  137°  (278.6°  F.).  Obtained  from 
normal  butyl  alcohol,  or  from  normal  amylamin.  It  yields  normal 
valerianic  acid  on  oxidation. 

Isobutyl  Carbinol— Amyl  alcohol—  cI^CH.C^.CH^OH— is  the 
principal  constituent  of  the  fusel  oil  from  grain  and  potatoes.  It 
is  obtained  from  the  last  milky  products  of  rectification  of  alcoholic 
liquids.  These  are  shaken  with  H2O  to  remove  ethyl  alcohol,  the 
supernatant  oily  fluid  is  decanted,  dried  by  contact  with  fused  calcium 
chlorid,  and  distilled;  that  portion  which  passes  over  between  128° 
and  132°  (262.4°-269.6°  F.)  being  collected. 

It  is  a  colorless,  oily  liquid,  has  an  acrid  taste  and  a  peculiar  odor, 
at  first  not  unpleasant,  afterward  nauseating  and  provocative  of 
severe  headache.  It  boils  at  131.4°  (236.5°  F.), and  crystallizes  at 
—20°  (4°  F.) ;  sp.  gr.  0.8184  at  15°  (5°  F.).  It  mixes  with  alcohol 
and  ether,  but  not  with  water.  It  burns  with  a  pale  blue  flame  when 
sufficiently  heated. 

When  exposed  to  air  it  oxidizes  very  slowly;  quite  rapidly,  how- 
ever, in  contact  with  platinum -black,  forming  isovalerianic  acid.  The 
same  acid,  along  with  other  substances,  is  produced  by  the  action  of 
the  more  powerful  oxidants  upon  amyl  alcohol.  Chlorin  attacks  it 
energetically,  forming  amyl  chlorid,  HC1,  and  other  chlorinated  de- 
rivatives. Sulfuric  acid  dissolves  in  amyl  alcohol,  with  formation  of 
amyl-sulfuric  acid,  SO4(C5Hn)H,  corresponding  to  ethyl -sulf uric  acid 
(p.  312) .  It  also  forms  similar  acids  with  phosphoric,  oxalic,  citric,  and 
tartaric  acids.  Its  esters,  when  dissolved  in  ethyl  alcohol,  have  the 
taste  and  odor  of  various  fruits,  and  are  used  in  the  preparation  of 
artificial  fruit -essences.  Amyl  alcohol  is  also  used  in  analysis  as  a 
solvent,  particularly  for  certain  alkaloids,  and  in  pharmacy  for  the 
artificial  production  of  valerianic  acid  and  the  valerianates. 

Diethyl  Carbinol  — cH3-CH!/CHOH~is  produced  by  the  action 
of  a  mixture  of  zinc  and  ethyl  iodid  on  ethyl  formate,  with  the 
subsequent  addition  of  H^O.  It  is  a  liquid  which  boils  at  116.5° 
(241. 7°  F.). 

Methyl-propyl  Carbinol — CH3— CH2— CHz/CHOII — a  ^Quid,  boil- 
ing at  118.5°  (245.3°  F.),  obtained  by  the  hydrogenation  of  inethyl- 
propylic  acetone. 


ALCOHOLS  — HYDROCARBON    HYDROXIDS  251 


Methyl-isopropyl  Carbinol —  /CH\_Qg3 /CHOH — obtained  by  the 
hydrogenation  of  methyl -isopropylic  acetone;  or  by  the  action  of  hy- 
driodic  acid  upon  amylene,  and  the  action  of  moist  silver  oxid  upon 
the  product  so  obtained.  It  is  a  colorless  liquid,  sp.  gr.  0.829  at  0° 
(32°  F.),  having  a  pungent,  ethereal  odor;  boils  at  112.5°  (234.5°  F.), 
soluble  in  H2O  and  in  alcohol. 

Ethyl-dimethyl  Carbinol — Tertiary  amylic  alcohol — Amylene  hy- 

CH3\ 
drate— CH3  —  CH2— COH— is  a  liquid  which  solidifies  at  —12°  (10.4° 


F.)  and  boils  at  102.5°  (216.5°  P.);  formed  by  the  action  of  zinc 
methyl  upon  propionyl  chlorid,  or  by  decomposition  of  tertiary  sulf- 
amylic  acid  by  boiling  H2O.  The  nitrite  of  this  alcohol  has  been  used 
as  a  substitute  for  amyl  nitrite. 

Cetyl  Hydroxid—  Cetylic  alcohol— Ethal—CioH.s3OK— 242  —  is  ob- 
tained by  the  saponification  of  spermaceti  (its  palmitic  ester).  It  is 
a  white,  crystalline  solid;  fusible  at  49°  (120.2°  F.)  ;  insoluble  in 
H20;  soluble  in  alcohol  and  ether;  tasteless  and  odorless. 

Ceryl  Hydroxid— C27H55OH— 396— and  Miricyl  Hydroxid— C3oH6i 
— OH — 438 — are  obtained  as  white  crystalline  solids;  the  former  from 
China  wax;  the  latter  from  beeswax,  by  saponification. 

DIATOMIC,    OR    DIHYDRIC    ALCOHOLS;    GLYCOLS. 

The  paraffin  glycols  are  derived  from  the  paraffins  by  the  substi- 
tution of  two  hydroxyls  for  two  H  atoms.  They  bear  the  same  rela- 
tion to  the  monoatomic  alcohols  that  the  diacid  bases  bear  to  the 
monacid  bases.  They  are  diprimary,  disecondary,  primary -secondary, 
etc.,  according  as  they  contain  groups  CH2OH ;  CHOH,  or  COH. 
Their  "  Geneva  "  names  are  derived  from  those  of  the  parent  hydro- 
carbons by  the  substitution  of  the  syllable  "diol"  for  the  terminal  e; 
and  they  are  distinguished  as  <*,  /?,  y,  S,  etc.,  according  as  the  hy- 
droxyls occupy  1:2,1:3,1:4,1:5,  etc.,  positions.  Thus  the  primary- 
secondary  glycol  CH2OH.CH2.CHOH.CH3,  is  /8-butandiol  (p.  290). 

They  may  be  obtained  from  the  neutral  haloid  esters  by  heating 
with  silver  acetate:  C2H4I2+2AgC2H3O2=2AgI-f  C2H4  (C2H3O2)2,  and 
saponification  of  the  ester  so  formed  by  caustic  potash:  C2H4(C2H3- 
O2)2+2KHO=C2H4(OH)2+2KC2H3O2  (see  p.  315). 

While  the  monoatomic  alcohols  are  only  capable  of  forming  a 
single  ester  with  a  monobasic  acid,  the  glycols  are  capable  of  forming 
two  such  esters: 

CH2  (C2H3O2) '  CH2  (C2H302 )'  CH2  (C2H3O2 )' 

CH3  CH2OH  CH2(C2H302)' 

Ethyl  acetate.  Monoacetic  glycol.  Diacetic  glycol. 


252  MANUAL    OF    CHEMISTRY 


Methene  Glycol,  which  would  have  the  composition  H2CQg,  is 
not  known  (p.  225).  Its  haloid  esters  are,  however,  known.  A  con- 
densation product  corresponding  to  it  exists  as  methene  dimethylate, 
H^KoCHs*  also  called  methylal  and  formal,  as  a  thin  liquid,  boiling 
at  42°  (107.6°  F.),  soluble  in  alcohol,  ether,  and  water,  sp.  gr.  0.855; 
formed  by  oxidizing  methyl  alcohol  with  H2S04  and  Mn(>2.  It  has 
been  used  as  a  medicine. 

Ethene  Glycol  —  Ethylene  glycol,  or  alcohol,  or  hydroxid  — 
CH2OH 

—  62.  —  This,  the  best  known  of  the  glycols,  is  prepared  by  the 
CHoOH 

action  of  dry  silver  acetate  upon  ethylene  bromid.  The  ester  so  ob- 
tained is  purified  by  redistillation,  and  decomposed  by  heating  for 
some  time  with  barium  hydroxid. 

It  is  a  colorless,  slightly  viscous  liquid;  odorless;  faintly  sweet; 
sp.  gr.  1.125  at  0°  (32°  F.)  ;  boils  at  197°  (386.6°  F.)  ;  sparingly  sol- 
uble in  ether;  very  soluble  in  water  and  in  alcohol. 

It  is  not  oxidized  by  simple  exposure  to  air,  but  on  contact  with 
platinum  -black  it  is  oxidized  to  glycolic  acid;  more  energetic  oxidants 
transform  it  into  oxalic  acid.  Chlorin  acts  slowly  upon  glycol  in  the 
cold;  more  rapidly  under  the  influence  of  heat,  producing  chlorinated 
and  other  derivatives.  By  the  action  of  dry  HC1  upon  cooled  glycol, 
a  product  is  formed,  intermediate  between  it  and  ethylene  chlorid,  a 

CH2OH 

neutral  compound  —  ethene  chlorhydrin,    I          ,  which  boils  at  130° 

CH2C1 

(266°  F.). 

TRIATOMIC,    OB    TRIHYDRIC    ALCOHOLS;    GLYCEROLS. 

These  are  derived  from  the  paraffins  by  the  substitution  of  three 
hydroxyls  for  three  hydrogen  atoms,  linked  to  different  carbon  atoms. 
The  simplest  triprimary  glycerol,  which  would  have  the  formula: 
CH(CH20H)3,  is  unknown.  The  simplest  known  representative  of 
the  class  is  the  ordinary  glycerine,  more  properly  called  glycerol, 
which  is  diprimary-  secondary.  The  relations  of  the  monoatomic,  di- 
atomic, and  triatomic  alcohols  to  each  other  and  to  the  parent  hydro- 
carbon are  shown  in  the  following  formula: 


CH3 

CH3 

CH2OH 

CH2OH 

CH2 

CH2 

CH2 

CHOH 

CH3 

CH2OH 

CH2OH 

CH2OH 

Propane, 

Propyl  alcohol. 

Propyl  glycol. 

Glycerol. 

The  Geneva  names  of  the  glycerols  are  derived  from  those  of  the 
hydrocarbons  by.  the  substitution  of  the  syllable  "  triol "  for  the  ter- 
minal e.  Thus  glycerol  is  propantriol. 


ALCOHOLS  — HYDROCARBON    HYDROXIDS  '  253 

They  are  obtained  by  the  saponification  of  their  esters,  either 
those  existing  in  nature  or  those  produced  artificially. 

They  combine  with  acids  to  form  three  series  of  esters,  known 
generically  as  monoglycerids,  diglycerids,  and  triglycerids,  formed 
by  the  combination  of  one  molecule  of  the  alcohol  with  one,  two,  or 
three  molecules  of  a  monobasic  acid.  The  names  of  the  individual 
esters  terminate  in  in,  and  have  a  prefix  indicating  the  number  of 
acid  residues.  Thus:C3H5(OH)2.C2H3O2  is  monacetin,  C3H5(OH) 
(C2H3O2)2  is  diacetin,  and  C3H5  (C2H3O2)3  is  triacetin  (p.  316). 

Glycerol — Glycerin— Propenyl  alcohol  —  Glycerinum  (U.  S.)— 
C3H5(OH)3 — 92 — was  first  obtained  as  a  secondary  product  in  the 
manufacture  of  lead  plaster ;  it  is  now  produced  as  a  by-product  in 
the  manufacture  of  soaps  and  of  stearin  candles.  It  exists  free  in 
palm-oil  and  in  other  vegetable  oils.  It  is  produced  in  small  quan- 
tity during  alcoholic  fermentation,  and  is  consequently  present  in 
wine  and  beer.  It  is  much  more  widely  disseminated  in  its  esters, 
the  neutral  fats,  in  the  animal  and  vegetable  kingdoms. 

It  has  been  obtained  by  partial  synthesis,  by  heating  for  some 
time  a  mixture  of  allyl  tribromid,  silver  acetate  and  acetic  acid,  and 
saponifying  the  triacetin  so  obtained. 

The  glycerol  obtained  by  the  process  now  generally  followed — 
the  decomposition  of  the  neutral  fats  and  the  distillation  of  the 
product  in  a  current  of  superheated  steam — is  free  from  the  impuri- 
ties which  contaminated  the  product  of  the  older  processes.  The 
only  impurities  likely  to  be  present  are  water,  which  may  be  recog- 
nized by  the  low  sp.  gr.,  and  sometimes  arsenic. 

Glycerol  is  a  colorless,  odorless,  syrupy  liquid,  has  a  sweetish 
taste;  sp.  gr.  1.26  at  15°  (59°  F.).  Although  it  cannot  usually  be 
caused  to  crystallize  by  the  application  of  the  most  intense  cold,  it 
does  so  sometimes  under  imperfectly  understood  conditions,  forming 
small,  white  needles  of  sp.  gr.  1.268,  and  fusible  between  17°  and  18° 
(62.6°  and  64. 6°  F.).  It  is  soluble  in  all  proportions  in  water  and 
alcohol,  insoluble  in  ether  and  in  chloroform.  It  is  a  good  solvent 
for  a  number  of  mineral  and  organic  substances  (glycerites  and  gly- 
ceroles) .  It  is  not  volatile  at  ordinary  temperatures.  When  impure 
glycerol  is  heated,  a  portion  distils  unaltered  at  275°-280°  (527°- 
536°  F.),  but  the  greater  part  is  decomposed  into  acrolein,  acetic  acid, 
carbon  dioxid,  and  combustible  gases.  It  may  be  distilled  unchanged 
in  a  current  of  superheated  steam  between  285°  and  315°  (545°-599° 
F.).  Pure  glycerol  distils  unchanged  at  290°  at  a  pressure  of  756 
mm.,  and  at  180°  at  20  mm. 

Concentrated  glycerol,  when  heated  to  150°  (302°  F.)  ignites  and 
burns  without  odor  and  without  leaving  a  residue,  and  with  a  pale 
blue  flame.  It  may  also  be  burnt  from  a  short  wick. 


254  MANUAL    OF    CHEMISTRY 

Glycerol  is  readily  oxidized,  yielding  different  products  with  differ- 
ent degrees  of  oxidation.  Platinum -black  oxidizes  it,  with  formation, 
finally,  of  EbO  and  CO2.  Oxidized  by  manganese  dioxid  and  H2SO4, 
it  yields  CO2  and  formic  acid.  If  a  layer  of  glycerol  diluted  with  an 
equal  volume  of  B^O  be  floated  on  the  surface  of  HNOa  of  sp.  gr.  1.5, 
a  mixture  of  several  acids  is  formed:  oxalic,  €2041X2;  glyceric,  CaB^U; 
formic,  CH^;  glycollic,  C2H4O3;  glyoxylic,  C2H4O4;  and  tartaric, 
C4HeO6.  When  glycerol  is  heated  with  potassium  hydroxid,  a  mix- 
ture of  potassium  acetate  and  formate  is  produced.  When  glycerol, 
diluted  with  20  volumes  of  H^O,  is  heated  with  Br;  CO2,  bromoform, 
glyceric  acid,  and  BBr  are  produced.  Phosphoric  anhydrid  removes 
the  elements  of  E^O  from  glycerol,  with  formation  of  acrolein 
(p.  372) .  A  similar  action  is  effected  by  heating  with  B2&O4,  or  with 
monopotassic  sulfate.  Seated  with  oxalic  acid,  glycerol  yields  C02 
and  formic  acid. 

The  presence  of  glycerol  in  a  liquid  may  be  detected  as  follows: 
Add  NaBO  to  feebly  alkaline  reaction,  and  dip  into  it  a  loop  of  Pt 
wire  holding  a  borax  bead;  then  heat  the  bead  in  the  blow- pipe  flame, 
which  is  colored  green  if  the  liquid  contain  TOO-  of  glycerol. 

The  glycerol  used  for  medicinal  purposes  should  respond  to  the 
following  tests:  (1)  its  sp.  gr.  should  not  vary  much  from  that  given 
above;  (2)  it  should  not  rotate  polarized  light;  (3)  it  should  not  turn 
brown  when  heated  with  sodium  nitrate;  (4)  it  should  not  be  colored 
by  B2S;  (5)  when  dissolved  in  its  own  weight  of  alcohol,  containing 
one  per  cent,  of  B2SO4,  the  solution  should  be  clear;  (6)  when  mixed 
with  an  equal  volume  B2SO4,  of  sp.  gr.  1.83,  it  should  form  a  limpid, 
brownish  mixture,  but  should  not  give  off  gas. 

POLYATOMIC,  OR  POLYHYDEIC  ALCOHOLS. 

Tetratomic  Alcohols  contain  four  hydroxyls.  The  best  known  is: 
Erythrol  —  Erytlirite  —  Phycite  —  Erythroglucin  —  CB2OB.- 
(CBOB)2-CB2OB  —  which  is  a  product  of  decomposition  of  erythrin, 
C2oB22Oio,  which  exists  in  the  lichens  of  the  genus  rocella.  It  crystal- 
lizes in  large,  brilliant  prisms;  very  soluble  in  B2O  and  in  hot  alco- 
hol, almost  insoluble  in  ether;  sweetish  in  taste;  its  solutions  neither 
affect  polarized  light,  nor  reduce  Fehling's  solution,  nor  are  capable 
of  fermentation.  Its  watery  solution,  like  that  of  sugar,  is  capable 
of  dissolving  a  considerable  quantity  of  lime,  and  from  this  solution 
alcohol  precipitates  a  definite  compound  of  erythrite  and  calcium. 
By  oxidation  with  platinum-black  it  yields  erythroglucic  acid,  C4BgO5. 
With  fuming  BNOs  it  forms  a  tetranitro  compound,  which  explodes 
under  the  hammer. 

Pentatomic,    or    Pentahydric  Alcohols — Pentites — contain    five 


ALDEHYDES  AND  KETONES  255 

hydroxyls.  The  only  member  of  the  group  known  to  exist  in  nature 
is  the  simplest  CsH^OHh,  called  adonite,  obtained  from  Adonis 
vernalis.  Other  members  of  the  series  are  obtained  by  reduction  of 
e  corresponding  aldopentoses  (p.  264). 

Hexatomic,  or  Hexahydric  Alcohols  —  Hexites  —  contain  six  hy- 
roxyls.  They  are  closely  related  to  the  sugars  (p.  265),  which  they 
resemble  in  their  properties,  although  they  do  not  reduce  Fehling's 
solution,  and  are  not  fermented  by  yeast.  They  are  obtained  by  re- 
duction of  the  corresponding  glucoses,  aldohexoses  and  ketohexoses 
(p.  268).  Three  hexites  occur  in  nature: 

Mannitol  —  Mannite—C^OR.  (CHOH)4.CH2OH—  constitutes  the 
greater  part  of  manna,  and  also  exists  in  a  number  of  other  plants. 
It  is  also  produced  during  the  so-called  mucic  fermentation  of  sugar, 
and  during  lactic  fermentation.  It  crystallizes  in  long  prisms,  odor- 
less, sweet;  fuses  at  166°  (330.8°  F.)  and  crystallizes  on  cooling; 
boils  at  200°  (396°  F.),  at  which  temperature  it  is  converted  into 
mannitan,  CeH^Os;  soluble  in  E^O,  very  sparingly  in  alcohol. 
When  oxidized  it  yields  first  mannonic,  then  mannosaccharic  acid 
(p.  297),  and  finally,  oxalic  acid.  Organic  acids  combine  with  it  to 
form  esters. 

Sorbitol  —  Sorbite  —  occurs  in  mountain-ash  berries.  It  forms 
crystals,  soluble  in  water. 

Dulcitol  —  Dulcite  —  Melampyrite  —  Dulcose  —  Dulcin  —  exists  in 
melampyrum  nemorosum.  It  forms  colorless,  transparent  prisms, 
fuses  at  182°  (359.6°  F.),  is  odorless,  faintly  sweet,  neutral  in  reac- 
tion, and  optically  inactive.  It  is  subject  to  decompositions  very 
similar  to  those  to  which  mannite  is  subject,  yielding  dulcitan, 


Heptatomic,  Octatomic  and  Nonatomic  Alcohols,  containing 
respectively  seven,  eight  and  nine  hydroxyls,  are  also  known. 

All  polyatomic  alcohols  in  solutions  alkalized  with  caustic  soda, 
when  agitated  with  benzoyl  chlorid,  form  insoluble  benzoic  esters, 
and,  under  proper  conditions,  the  separation  is  quantitative,  a  fact 
which  is  utilized  for  their  separation.  The  diamins  (p.  330)  behave 
similarly  with  benzoyl  chlorid. 

ALDEHYDES    AND    KETONES. 

The  pure  aldehydes  and  ketones,  containing  only  CHO  or  CO  and 
hydrocarbon  groups,  are  to  be  considered  rather  as  the  second  prod- 
ucts of  oxidation  of  the  paraffins  than  as  the  first  products  of  oxi- 
dation of  the  alcohols,  primary  or  secondary.  While  the  distinction 
is  not  material  with  the  aldehydes  derivable  from  the  monoatomic 
alcohols,  it  is  so  with  similar  derivatives  of  alcohols  of  higher  atom- 


256  MANUAL    OF    CHEMISTRY 

icity  and  with  the  ketones,  which  may  be  either  pure  aldehydes  or 
ketones,  or,  if  they  retain  alcoholic  groups,  substances  of  mixed 
function:  aldehyde -alcohols  and  ke  tone -alcohols.  Thus  from  the 
hydrocarbons  the  following  may  be  derived: 

2(CH3.CH3)+02=2(CH3.CH2OH)  =  Alcohols— Cn  H2n  +  2O, 

CH3.CH3+O2=H2O+CH3.CHO  =  Aldehydes— Cn  H2nO, 

CH3.CH3H-2O2=2H2O-hCHO.CHO          =  Glyoxals— CnH2n-2O2, 

CH3.CH2.CH3+02=H2O+CH3.CO.CH3  =  Ketones— Cn  H2n  O, 

and  from  the  alcohols  not  only  the  above,  but  also  substances  such  as 

2(CH2OH.CH2OH)-fO2=2H2O-h2(CHO.CH2OH)=Glycolyl  aldehyde, 
2(CH2OH.CHOH.CH2OH)+02=2H20+2(CHO.CHOH.CH2OH)=Glycerol  aldehyde, 
2(CH2OH.CHOH.CH2OH)+02=2H2OH-2(CH2OH.CO.CH2OH)  =Glycerol  ketone. 

The  aldehydes  and  ketones  are  isomeric  with  each  other  and  also 
with  the  allyl  alcohols,  CH2:CH.CH20H,  and  the  methylene  oxids, 
(CH2)*:0. 

Both  aldehydes  and  ketones  contain  the  carbonyl  group  CO,  which 
in  the  ketone  is  united  to  two  alkyls,  CHs.CO.CHs;  and  in  the  alde- 
hyde to  one  alkyl  and  a  hydrogen  atom,  CHs.CO.H. 

The  aldehydes  and  ketones  react  with  hydroxylamin  to  form  aldox- 
isms  and  ketoxims  (p.  360),  and  with  phenylhydrazin  to  form  phenyl- 
hydrazones  (p.  429).  Both  of  these  reactions  are  extensively  used 
for  the  identification  of  these  bodies. 

ALDEHYDES. 

The  name  "aldehyde"  is  a  contraction  of  "alcohol  dehydrogen- 
atum,"  derived  from  the  method  of  formation  of  these  bodies  by 
removal  of  hydrogen  from  alcohol. 

The  aldehydes  are  formed:  (1)  By  the  limited  oxidation  of  the 
corresponding  alcohols:  2CH3.CH2OH+O2  =  2CH3.CHO+2H2O;  (2) 
By  the  action  of  nascent  hydrogen  upon  the  corresponding  acidyl 
chlorids  (p.  311),  or  anhydrids  (p.  310):  CHg.CO.Cl+Ha^CHs.- 
CHO  +  HC1,  or  (CH3.CO)2O+2H2  =  2CH3.CHO+H2O;  (3)  By  the 
distillation  of  a  mixture  of  calcium  formate  and  the  Ca  salt  of  the 
corresponding  acid:  (H.COO)20a+(CH3.COO)2Ca=2CO8Ca+2CH3.- 
CHO. 

The  aldehydes,  being  intermediate  between  the  alcohols  and  acids, 
are  readily  converted  into  the  former  by  the  action  of  reducing  agents : 
CH3.CHO  +  H2=CH3.CH2OH;  or  into  the  latter  by  oxidation: 
2CH3.CHO+O2  =  2CH3.COOH.  The  facility  with  which  the  alde- 
hydes are  oxidized  renders  them  active  reducing  agents. 

They  combine  with  the  monometallic  alkaline  sulfites  to  form  crys- 
talline compounds,  whose  formation  is  frequently  resorted  to  for  their 
separation  and  purification: 


ALDEHYDES    AND    KETONES  257 


They  unite  directly  with  ammonia  to  produce   crystalline   com- 
pounds called   aldehyde  ammonias   (p.   360):    CH3.CHO  +  NH3  = 


Chlorin  and  bromin  displace  the  hydrogen  of  the  aldehydic  group 
with  formation  of  acidyl  chlorids  or  bromids:  CH3.CHO-{-Cl2  = 
CHs.CO.Cl+HCl.  The  oxygen  of  the  same  group  may  also  be  dis- 
placed by  chlorin,  by  the  action  of  phosphorus  pentachlorid,  with 
formation  of  paraffin  dichlorids:  CH3.CHO+PC15  =  CH3.CHC12+ 
POC13.  By  indirect  means  compounds  may  also  be  obtained  in  which 
the  hydrogen  of  the  hydrocarbon  group  is  substituted  by  chlorin,  as 
chloral  is  obtained  from  ethylic  alcohol:  CH3.CH2OH+4CljF=CCl3.- 
CHO+5HC1. 

The  aldehydes  polymerize  readily,  forming  cyclic  compounds,  as  tri- 

/f  TT    O\ 

oxymethylene  is  formed  by  formic  aldehyde:  SH-CHO^O^Qg^o/CH^ 
Or  two  aldehyde  molecules  may  condense,  by  union  through  carbon 
atoms,  to  form  oxyaldehydes  (p.  263),  as  aldol  is  formed  by  conden- 
sation of  acetic  aldehyde:  2CH3.CHO=CH3.CHOH.CH2.CHO. 

Hydrocyanic  acid  combines  with  the  aldehydes  (and  ketones)  to 
produce  oxycyanids,  or  nitrils  of  the  oxyacids:  CH3.CHO+HCN= 
CH3.CH\Q^  which,  in  turn,  are  decomposable  by  acids  or  alkalies 
with  formation  of  the  a-oxyacids  (p.  291). 

Formaldehyde  —  Formyl  hydrid  —  H.CHO  —  30  —  is  formed  when 
air  charged  with  vapor  of  methylic  alcohol  is  passed  over  an  incan- 
descent platinum  wire.  It  is  also  produced  by  the  dry  distillation  of 
calcium  formate:  (H.COO)2Ca=CaCO3+H.COH.  By  strong  cooling, 
it  condenses  to  a  colorless  liquid,  which  boils  at  —  21°  (  —  5.8°  F.).  It 
has  a  sharp,  penetrating  odor,  and  is  an  active  germicide.  It  is  exten- 
sively used  as  an  antiseptic  and  disinfectant,  either  in  the  gaseous 
form  or  in  aqueous  solution.  The  commercial  formaline  is  a  40% 
solution. 

Formaldehyde  polymerizes  with  great  readiness  by  moderate  ele- 
vation of  temperature  to  form  paraformaldehyde,  or  trioxymethylene, 

°\CH2!o/CH2'  which  is  also  obtained  as  a  crystalline  substance, 
fusing  at  152°  (305.6°  F.),  insoluble  in  H2O,  alcohol  and  ether,  by 
distilling  glycollic  acid  with  H2SO4,  or  by  the  action  of  silver  oxalate 
or  oxid  on  methene  iodid:  CH2I2+Ag2O=H.CHO+2AgI. 

Acetaldehyde—  Acetic  Aldehyde  —Acetyl  hydrid—  CH3.CHO—  44 
—  is  formed  in  all  reactions  in  which  alcohol  is  deprived  of  H  without 
introduction  of  O.  It  is  prepared  by  distilling  from  a  capacious  retort, 
connected  with  a  well-cooled  condenser,  a  mixture  of  H2SO4,  6  pts.; 
H2O,  4  pts.;  alcohol,  4  pts.,  and  powdered  manganese  dioxid,  6  pts. 
The  product  is  redistilled  from  calcium  chlorid  below  50°  (122°  F.). 
17 


258  MANUAL    OF    CHEMISTRY 

The  second  distillate  is  mixed  with  two  volumes  of  ether,  cooled  by  a 
freezing  mixture,  and  saturated  with  dry  NHs;  there  separate  crys- 
tals of  aldehyde  ammonia,  CHa.CH/Qg2,  which  are  washed  with 
ether,  dried  and  decomposed  in  a  distilling  apparatus,  over  the  water- 
bath,  with  the  proper  quantity  of  dilute  H^SCU;  the  distillate  is  finally 
dried  over  calcium  chlorid  and  rectified  below  35°  (95°  F.). 

Aldehyde  is  a  colorless,  mobile  liquid;  has  a  strong,  suffocating 
odor;  sp.  gr.  0.790  at  18°  (64.4°  F.) ;  boils  at  21°  (69.8°  F.) ;  soluble 
in  all  proportions  in  water,  alcohol  and  ether.  If  perfectly  pure,  it 
may  be  kept  unchanged;  but  if  an  excess  of  acid  have  been  used  in 
its  preparation,  it  gradually  decomposes.  When  heated  to  100°  (212° 
F.),  it  is  decomposed  into  water  and  crotonic  aldehyde. 

In  the  presence  of  nascent  H,  aldehyde  takes  up  H2,  and  regen- 
erates alcohol.  Cl  converts  it  into  acetyl  chlorid,  C2H3O.C1,  and 
other  products.  Oxidizing  agents  convert  it  into  acetic  acid.  At 
the  ordinary  temperature  H2SO4;  HC1;  and  862  convert  it  into  a 
colorless  liquid  called  paraldehyde  (C2H4O)3,  which  boils  at  124° 
(255.2°  F.),  and  is  more  soluble  in  cold  than  in  warm  water.  The 
same  reagents,  acting  upon  aldehyde  at  temperatures  below  0°  (32°  F.) 
convert  it  into  metaldehyde  (C2H4O)*.  When  heated  with  potassium 
hydroxid,  aldehyde  becomes  brown,  a  brown  resin  separates,  and 
the  solution  contains  potassium  formate  and  acetate.  If  a  watery 
solution  of  aldehyde  be  treated,  first  with  NHs  and  then  with  H2S,  a 
solid,  crystalline  base,  thialdin,  CeHi3NS2,  separates.  It  also  forms 
crystalline  compounds  with  the  alkaline  bisulfites.  It  decomposes 
solutions  of  silver  nitrate,  separating  the  silver  in  the  metallic  form, 
and  under  conditions  which  cause  it  to  adhere  strongly  to  glass. 

Vapor  of  aldehyde,  when  inhaled  in  a  concentrated  form,  produces 
asphyxia,  even  in  comparatively  small  quantity.  When  diluted  with 
air  it  is  said  to  act  as  an  anaesthetic.  When  taken  internally  it 
causes  sudden  and  deep  intoxication,  and  it  is  to  its  presence  that  the 
first  products  of  the  distillation  of  spirits  of  inferior  quality  owe  in  a 
great  measure  their  rapid,  deleterious  action. 

Trichloraldehyde  —  TriMoracetyl  hydrid — Chloral — CC13.CHO  — 
147.5 — is  one  of  the  final  products  of  the  action  of  Cl  upon  alcohol, 
and  is  obtained  by  passing  dry  Cl  through  absolute  alcohol  to  satu- 
ration; applying  heat  toward  the  end  of  the  reaction,  which  requires 
several  hours  for  its  completion.  The  liquid  separates  into  two 
layers;  the  lower  is  removed  and  shaken  with  an  equal  volume  of 
concentrated  H^SO*  and  again  allowed  to  separate  into  two  layers; 
the  upper  is  decanted;  again  mixed  with  EbSCU,  from  which  it  is 
distilled;  the  distillate  is  treated  with  quicklime,  from  which  it  is 
again  distilled,  that  portion  which  passes  over  between  94°  and  99° 


ALDEHYDES    AND    KETONES  259 

(201.2°-210.2°  F.)  being  collected.  It  sometimes  happens  that 
chloral  in  contact  with  H^SCU  is  converted  into  a  modification,  in- 
soluble in  IkO,  known  as  metachloral ;  when  this  occurs  it  is  washed 
with  H2O,  dried  and  heated  to  180°  (356°  F.),  when  it  is  converted 
into  the  soluble  variety,  which  distils  over. 

Chloral  is  a  colorless  liquid,  unctuous  to  the  touch;  has  a  pene- 
trating odor  and  an  acrid,  caustic  taste;  sp.  gr.  1.502  at  18°  (64.4° 
F.);  boils  at  97°  (206.6°  F.),  very  soluble  in  water,  alcohol,  and 
ether  ;  dissolves  01,  Br,  I,  S,  and  P.  Its  vapor  is  highly  irritating. 
It  distils  without  alteration. 

Although  chloral  has  not  been  obtained  by  the  direct  substitution 
of  Cl  for  H  in  aldehyde,  its  reactions  show  it  to  be  an  aldehyde.  It 
forms  crystalline  compounds  with  the  bisulfites;  it  reduces  solutions 
of  silver  nitrate  in  the  presence  of  NH3;  NH3  and  H2S  form  with  it  a 
compound  similar  to  thialdin;  with  nascent  H  it  regenerates  alde- 
hyde; oxidizing  agents  convert  it  into  trichloracetic  acid.  Alkaline 
solutions  decompose  it  with  formation  of  chloroform  and  a  formate. 

With  a  small  quantity  of  H2O  chloral  forms  a  solid,  crystalline 
hydrate,  heat  being  at  the  same  time  liberated.  This  hydrate  has  the 
composition  C2HC13O.H2O,  and  its  constitution,  as  well  as  that  of 
chloral  itself,  is  indicated  by  the  formula  : 

CH3                                 CC13  CC13 

I                                      I  I 

CHO                                    CHO  CH(OH)2 

Aldehyde.                             Trichloraldehyde  Chloral  hydrate, 

(chloral).  (See  p.  225). 

Chloral  Hydrate — Chloral  (U.  S.) — is  a  white,  crystalline  solid; 
fuses  at  57°  (134.6°  F.) ;  boils  at  98°  (208.4°  F.),  at  which  tempera- 
ture it  suffers  partial  decomposition  into  chloral  and  H2O ;  volatilizes 
slowly  at  ordinary  temperatures;  is  very  soluble  in  H2O;  neutral  in 
reaction;  has  an  ethereal  odor,  and  a  sharp,  pungent  taste.  Concen- 
trated H2SO4  decomposes  it  with  formation  of  chloral  and  chloralid. 
HNO3  converts  it  into  trichloracetic  acid.  When  pure  it  gives  no 
precipitate  with  silver  nitrate  solution,  and  is  not  browned  by  con- 
tact with  concentrated  H2SO4.  Under  the  influence  of  sunlight  it  is 
violently  decomposed  by  potassium  chlorate;  chlorin,  phosgene  gas, 
carbon  dioxid,  and  chloroform  are  given  off,  and  after  a  time,  crys- 
tals of  potassium  trichloracetate  separate  from  the  cooled  mixture. 

Chloral  also  combines  with  alcohol,  with  elevation  of  tem- 
perature, to  form  a  solid,  crystalline  body — chloral  alcoholate: 

CC13CH\0_  c2H5. 

Action  of  Chloral  Hydrate  upon  the  Economy.— Although  it 
was  the  ready  decomposition  of  chloral  into  a  formate  and  chloroform 
which  first  suggested  its  use  as  a  hypnotic  to  Liebreich,  and  although 


260  MANUAL    OF    CHEMISTRY 

this  decomposition  was  at  one  time  believed  to  occur  in  the  body 
under  the  influence  of  the  alkaline  reaction  of  the  blood,  more  recent 
investigations  have  shown  that  the  formation  of  chloroform  from 
chloral  in  the  blood  is,  to  say  the  least,  highly  improbable,  and  that 
chloral  has,  in  common  with  many  other  chlorinated  derivatives  of 
this  series,  the  property  of  acting  directly  upon  the  nerve -centers. 

Neither  the  urine  nor  the  expired  air  contains  chloroform  when 
chloral  is  taken  internally;  and  when  taken  in  large  doses,  chloral 
appears  in  the  urine.  The  fact  that  the  action  of  chloral  is  pro- 
longed for  a  longer  period  than  that  of  the  other  chlorinated  deriva- 
tives of  the  fatty  series  is  probably  due,  in  a  great  measure,  to  its 
less  volatility  and  less  rapid  elimination. 

When  taken  in  overdose,  chloral  acts  as  a  poison,  and  its  use  as 
such  is  rapidly  increasing  as  acquaintance  with  its  powers  becomes 
more  widely  disseminated.  A  strong  aqueous  solution  is  frequently 
added  by  criminals  to  intoxicants  to  deprive  their  victims  of  con- 
sciousness (knock-out  drops). 

No  chemical  antidote  is  known.  The  treatment  should  be  directed 
to  the  removal  of  any  chloral  remaining  in  the  stomach  by  the 
syphon,  and  to  the  maintenance  or  restoration  of  respiration. 

In  fatal  cases  of  poisoning  by  chloral  that  substance  may  be 
detected  in  the  blood,  urine,  and  contents  of  the  stomach  by  the 
following  method:  the  liquid  is  rendered  strongly  alkaline  with  po- 
tassium hydroxid:  placed  in  a  flask,  which  is  warmed  to  50°-60° 
(122°-140°  F.),  and  through  which  a  slow  current  of  air,  heated 
to  the  same  temperature,  is  made  to  pass;  the  air,  after  bubbling 
through  the  liquid,  is  tested  for  chloroform  by  the  methods  described 
on  page  235.  As  chloral  distils  with  vapor  of  water  from  acid  solu- 
tions, and  as  it  gives  the  same  reactions  as  chloroform,  except  the 
fluorescence  with  the  resorcinol  reaction  (p.  235),  the  presence  of 
chloral  as  such  can  only  be  positively  demonstrated  by  extraction  of 
the  crystals  of  the  hydrate  by  ether,  and  spontaneous  evaporation  of 
the  ethereal  solution. 

Bromal — CBrs.CHO — 281. — A  colorless,  oily,  pungent  liquid:  sp. 
gr.  3.34;  boils  at  172°  (341.6°  F.);  neutral;  soluble  in  H2O,  alcohol, 
and  ether.  It  combines  with  H2O  to  form  bromal  hydrate,  CBrs. 
CHXOHh;  large  transparent  crystals;  soluble  in  H2O;  decomposed 
by  alkalies  into  bromoform  and  a  formate.  Produces  anaesthesia 
without  sleep;  very  poisonous. 

Thioaldehydes. — By  the  action  of  EbS  on  aldehyde  in  the  pres- 
ence of  HC1  two  products  are  obtained,  having  the  composition 
(CHaCHSh,  known  as  <*  and  ft  Trithioacetaldehyde.  The  former 
is  in  large  prismatic  crystals,  fusible  at  101°  (213.8°  F.),  the  latter  in 
long  needles,  fusible  at  125°-126°(257°-258.80  F.). 


ALDEHYDES    AND    KETONES  261 

Propaldehyde  —  Propionic  aldehyde  —  CH3  .  CH2  .  CHO  —  58  —  ob- 

tained by  the  general  reaction  from  propylic  alcohol,  is  a  colorless 
liquid,  resembling  acetic  aldehyde;  boils  at  40°  (120.2°  F.). 

Normal  Butaldehyde—  Butyric  aldehyde—  CH3.CH2.CH2.CHO— 
72—  is  an  oily  liquid,  boiling  at  73°  (163.4°  F.).  Its  trichlorinated 
derivative,  Trichlorbutaldehyde,  or  Butyric  chloral,  CC13.CH2.CHO 
—  is  the  substance  whose  hydrate  is  used  as  a  medicine  under  the 
name  croton  chloral  hydrate.  It  is  a  colorless  liquid,  boiling  at  160° 
(320°  F.),  obtained  by  the  action  of  Cl  on  acetaldehyde. 

Acetals.  —  The  chloral  alcoholate  referred  to  above  (p.  259)  is  a 

/OTT 

mono-ether  of  chloral  hydrate  CCl3.CH<^OC2H5,  whose  corresponding 


di-ether  is  CCls.CHoCsHs,  trichloracetal.  The  acetals  are  sub- 
stances derived  from  the  hypothetical  aldehyde  hydrates,  correspond- 
ing to  chloral  hydrates,  by  the  substitution  of  alkyls  for  the  hydro- 
gens of  the  hydroxyls. 

Methylal—  Formal—  CH2<(ocH3~76~is  formed  by  distilling  a 
mixture  of  MnO2,  methyl  alcohol,  H2SO4  and  H20.  It  is  a  colorless 
liquid;  sp.  gr.  0.8551  at  17°  (62.6°  F.);  boiling  at  42°  (107.6°  F.); 
soluble  in  H20,  alcohol,  and  oils.  It  has  a  burning,  aromatic  taste, 
and  an  odor  resembling  those  of  chloroform  and  acetic  acid.  It  has 
been  used  as  a  hypnotic. 

Acetal—  CHa.CH^oc'Hj—  104-  a  colorless  liquid,  boils  at  104° 
(219.2°  F.),  sp.  gr.  0.8314;  sparingly  soluble  in  H2O,  readily  in  al- 
cohol; obtained  by  heating  a  mixture  of  aldehyde,  alcohol  and  glacial 
acetic  acid,  or  in  the  same  manner  as  formal,  using  ethylic  in  place  of 
methylic  alcohol. 

Dialdehydes  —  containing  two  CHO  groups,  such  as  Glyoxal  — 
CHO.CHO,  are  also  known. 

KETONES    OR    ACETONES. 

These  substances  all  contain  the  group  of  atoms  (  CO  )"  uniting 
two  hydrocarbon  groups,  and  their  constitution  may  be  represented 
graphically  thus: 

CH3 

OH  CH3 

I  I  CO 

CO  CO 

I  I  CH, 

CH3  CH3  I 

CHa 

Acetic  Acid.  Dimethyl  ketone  Methyl-ethyl  ketone. 

(acetone). 

the  first  being  a  symmetrical  ketone  and  the  latter  an  unsym- 
metrical.  The  ke  tones  are  isomeric  with  the  aldehydes,  from  which 
they  are  distinguished:  (1)  by  the  action  of  nascent  H,  which  pro- 


262  MANUAL    OF    CHEMISTRY 

duces  a  primary  alcohol  with  an  aldehyde,  and  a  secondary  alcohol 
with  a  ketone;  (2)  by  the  action  of  O,  which  unites  directly  with  an 
aldehyde  to  produce  the  corresponding  acid,  while  it  causes  the  dis- 
ruption of  the  molecule  of  the  ketone,  with  formation  of  two  acids. 

Dimethyl  Ketone — Acetone — Acetylmethylid — Pyroacetic  ether  or 
spirit — CO\CK  —58 — is  formed  as  one  of  the  products  of  the  dry 
distillation  of  the  acetates;  by  the  decomposition  of  the  vapor  of 
acetic  acid  at  a  red  heat ;  by  the  dry  distillation  of  sugar,  tartaric 
acid,  etc.;  and  in  a  number  of  other  reactions.  It  is  obtained  by 
distilling  dry  calcium  acetate.  It  is  also  formed  in  large  quantity  in 
the  preparation  of  anilin. 

It  is  a  limpid,  colorless  liquid;  sp.  gr.  0.7921  at  18°  (64.4°  F.); 
boils  at  56°  (132. 8° F.);  soluble  in  H2O,  alcohol  and  ether;  has  a 
peculiar  ethereal  odor  and  a  burning  taste;  is  a  good  solvent  of 
resins,  fats,  camphor,  gun-cotton;  readily  inflammable.  It  forms 
crystalline  compounds  with  the  alkaline  bisulfites.  Cl  and  Br,  in  the 
presence  of  alkalies,  convert  it  into  chloroform  or  bromoform;  Cl 
alone  produces  with  acetone  a  number  of  chlorinated  products  of  sub- 
stitution. Certain  oxidizing  agents  transform  it  into  a  mixture  of 
formic  and  acetic  acids;  others  into  oxalic  acid. 

Acetone  has  been  found  to  exist  in  the  blood  and  urine  in  certain 
pathological  conditions,  and  notably  in  diabetes.  The  peculiar  odor 
exhaled  by  diabetics  is  produced  by  this  substance,  which  has  also 
been  considered  as  being  the  cause  of  the  respiratory  derangements 
and  coma  which  frequently  occur  in  the  last  stages  of  the  disease. 

That  acetone  exists  in  the  blood  in  such  cases  is  certain:  it  is  not 
certain,  however,  that  its  presence  produces  the  condition  designated 
as  acetonaemia.  It  can  hardly  be  doubted  that  the  acetone  thus  ex- 
isting in  the  blood  is  indirectly  formed  from  diabetic  sugar,  and  it  is 
probable  also  that  a  complex  acid,  known  as  ethyldiacetic,  CeHgOaH,  is 
formed  as  an  intermediate  product. 

See  aromatic  ketones. 

Diketones,  containing  two  CO  groups,  such  as  CHa.CO.CO.CHs, 
triketones,  such  as  CH3.CO.CO.CO.CH3,  and  tetraketones,  such  as 
CH3.(CO)4.CH3,  are  also  known. 


ALDEHYDE-ALCOHOLS,  KETONE-ALCOHOLS,  ALDEHYDE- KETONES, 
AND  OXYALDEHYDE-KETONES. 

These  bodies  are,  as  the  names  indicate,  substances  of  mixed  func- 
tion. The  known  oxy aldehyde -ketones,  aldehyde -ketones,  and  such  of 
the  aldehyde-  and  ketone -alcohols  as  contain  hydrocarbon  groups  are 
neither  numerous  nor  important.  The  following  formula?  indicate 
their  structure: 


ALDEHYDE- ALCOHOLS  — KETONE- ALCOHOLS,  ETC.      263 

CHO  CHO  CHO  CH2OH 

I  I  I  I 

CO  CO  CHOH  CO 

CH2OH                         CH3  C2H5  CH3 

Oxyaldehyde-  Aldehyde-  Aldehyde-  Ketone 

ketone.                               ketone.  alcohol.  alcohol. 

Oxypyroracemic                      Methyl  Aldol.  Acetol. 
aldehyde.                           Glyoxal. 

The  aldehyde -alcohols,  such  as  aldol  and  glycolyl  aldehyde: 
CH2OH.CHO,  are  called  oxyaldehydes. 

On  the  other  hand,  some  of  the  more  important  of  the  carbohy- 
drates, such  as  glucose,  maltose  and  fructose,  are  hexatomic  aldehyde- 
alcohols,  or  ketone -alcohols,  in  which  all  of  the  groups  are  oxidized. 


CARBOHYDRATES. 


The  definition  of  the  term  carbohydrate  as  "a  substance  of  un- 
known constitution  composed  of  carbon,  hydrogen  and  oxygen,  in 
which  the  oxygen  and  hydrogen  are  in  the  same  proportion  as  in 
water"  was  self -destructive  so  soon  as  the  constitution  of  these  sub- 
stances should  become  known,  as  it  now  has.  Yet  the  first  words  of 
the  definition  were  necessary  to  exclude  substances  such  as  acetic  acid, 
C2H402,  which  would  otherwise  accord  with  the  definition,  yet  were 
never  considered  as  carbohydrates.  But,  while  the  sugars  and 
starches  have  been  thus  removed  from  the  "miscellaneous"  residuum 
of  our  chemical  classification,  they  are  still  conveniently  referred  to 
as  carbohydrates  in  physiological  chemistry. 

The  carbohydrates  are  classified  into: 

Monosaccharids,  or  Monoses' — which  do  not  yield  any  other 
sugar  or  sugars  by  the  action  upon  them  of  dilute  acids  (glucose, 
fructose,  galactose,  etc.); 

Disaccharids,  or  Saccharobioses — which,  under  the  influence  of 
dilute  acids,  take  up  EkO  and  yield  two  other  sugar  molecules  (sac- 
charose, lactose,  maltose,  etc.); 

Trisaccharids,  or  Saccharotrioses — which,  under1  the  same  in- 
fluence, take  up  2H2O  and  yield  three  other  sugar  molecules;  and 

Polysaccharids — which,  under  the  same  influence,  take  up  more 
than  2H2O,  and  yield  more  than  three  sugar  molecules  (starches, 
gums,  celluloses,  etc.). 

The  disaccharids,  trisaccharids  and  poly sacchar ids  may  be  consid- 
ered as  produced  by  the  fusion  of  two  or  more  monosaccharid  mole- 
cules with  elimination  of  one  or  more  molecules  of  water. 

Those  carbohydrates  which  contain  the  ketone  group,  CO,  are 
called  ketoses,  those  containing  the  aldehyde  group,  CHO,  aldoses. 
The  names  of  all  carbohydrates  terminate  in  ose. 


264 


MANUAL    OF    CHEMISTRY 


MONOSACCHARIDS — MONOSES 

Monosaccharids  are  bioses,  trioses,  tetroses,  pentoses,  hexoses, 
heptoses,  octoses  or  nonoses  according  as  they  contain  from  two  to 
nine  carbon  atoms: 


Aldoses. 


:o 
:2OH 

CHO 
CHOH 
CH2OH 

CHO 
(CHOH)2 
CH2OH 

CHO 
(CHOH)3 
CH2OH 

CHO 

I 


CHO 

I 


(CHOH)4    (CHOH)5 

CJ 


CH2OH 


Ketoses. 


CH2OH    CH2OH 


CH2OH 
CO 


CH2OH        CH2OH 

I  I 

CO  CO 


CHOH       (CHOH)2    (C 


CH2OH    CHOH       (CHOH)2    (CHOH)3     (CHOH)4 


CH2OH 


;H2OH       CH2OH        CH2OH 


Dioses.       Trioses.     Tetroses.        Pentoses.         Hexoses. 


Heptoses. 


CHO 

CHO 

1 

1 

(CHOH)e 

(CHOH)7 

I 
CH2OH 

CH2OH 

CH2OH 

CH2OH 

I 

I 

CO 

CO 

(CHOH)5 

(CHOH)B 

1 

1 

CH2OH 

CH2OH 

Octoses. 

Nonoses. 

The  monosaccharids  are  neutral  substances,  sweet,  odorless,  white, 
insoluble  in  ether,  sparingly  soluble  in  alcohol,  and  readily  soluble  in 
water.  Like  all  aldehydes  and  ketones,  they  are  readily  oxidized,  and 
in  their  oxidation  act  as  reducing  agents.  It  is  upon  this  quality  that 
the  several  "reduction  tests,"  such  as  Trommer's,  Fehling's,  Barfoed's, 
Boettger's,  Mulder-Neubauer's,  etc.,  are  based.  Another  quality  of 
the  monosaccharids,  utilized  for  their  separation  and  identification,  is 
that  they  all  give  crystalline  precipitates  of  substances  called  osazones 
when  their  solutions,  acidulated  with  acetic  acid,  are  heated  with 
phenyl-hydrazin,  CeH5.H:N.N:H2.  The  trioses,  hexoses  and  nonoses 
are  capable  of  alcoholic  fermentation,  the  others  are  not.  Most  of 
the  monosaccharids  are  optically  active. 


DIOSES,    TRIOSES,    TETROSES  AND  PENTOSES. 

Glycolyl  aldehyde,  CH2OH.CHO,  is  the  only  diose  possible.  It 
is  produced  by  the  action  of  baryta  water  upon  brom-acetaldehyde. 

The  two  possible  trioses :  Glycerol  aldehyde,  CHO. CHOH. CH2OH, 
and  Glycerol  ketone,  CH2OH.CO.CH2OH,  are  not  known  in  the  pure 
state,  but  a  mixture  of  the  two  is  produced  when  glycerol  is  oxidized 
by  dilute  nitric  acid. 

Similarly  erythrose  is  a  mixture  of  the  two  tetroses,  CHO.- 
(CHOH)2.CH2OH  and  CH2OH,CHOH.CO.CH2OH,  formed  by  oxida- 
tion of  erythrol  by  dilute  nitric  acid. 

The  pentoses  hitherto  described  are  all  aldo- pentoses,  C4H5- 
( OH) 4. CHO,  although  keto- pentoses  probably  also  exist.  When 


ALDEHYDE- ALCOHOLS  —  KETONE- ALCOHOLS,  ETC.  265 

distilled  with  hydrochloric  or  dilute  sulf uric  acid  they  yield  f urf urole : 

/CH:CH 

CHO.(CHOH)3.CH2OH  =  3H20+CHO.(\        |     ;    a  reaction  which 

CH.O 

is  utilized  for  their  quantitative  determination.  Arabinose  is  a  pen- 
tose  obtained  by  the  action  of  dilute  sulf  uric  acid  upon  cherry  gum. 
Xylose,  or  wood  sugar,  is  produced  by  boiling  wood -gum  with  dilute 
acid.  Ribose  is  a  synthetic  product.  Rhamnose,  or  Isodulcite, 
Chinovose,  and  Fucose  are  methyl -pentoses:  CH3.(CHOH)4.CHO, 
obtained  by  the  decomposition  of  certain  glucosids  or  from  sea  weeds. 
These  pentoses  result  from  the  hydrolysis  of  pentosanes,  polysacchar- 
ids  occurring  as  gums  in  plants.  Pentoses  have  also  been  found  in 
the  urine,  particularly  in  diabetes  and  after  the  use  of  certain  fruits 
containing  pentosanes.  They  are  also  among  the  products  of  decom- 
position of  certain  nucleoproteids.  Pentoses,  when  warmed  with 
hydrochloric  acid  in  presence  of  phloroglucin,  give  a  fine  red  color, 
and  a  sharp  absorption  band  near  the  Na  line. 


HEXOSES— GLUCOSES . 


In  this  class  are  included  some  well-known  sugars,  such  as  glucose 
and  fructose,  which  occur  free  in  the  vegetable  world.  They  exist  in 
ether-like  combination  in  many  of  the  glucosids  (p.  409). 

They  are  mostly  sweet,  crystalline  substances,  very  soluble  in 
water,  and  difficultly  soluble  in  alcohol.  They  are  formed  by  (1)  the 
hydrolysis  of  the  di-  and  polysaccharids :  Ci2H22Oii+H2O=2C6Hi2O6, 
or  ^(CeHioOs)  -hwH^O^nCeH^Oe;  (2)  by  oxidation  of  the  correspond- 
ing hexatomic  alcohol;  (3)  by  reduction  of  the  lactones  of  the  mono- 
carboxylic  acids  (p.  320). 

They  exhibit  the  usual  reactions  of  the  alcohols  and  those  of  the 
aldehydes  orketones.  On  reduction  they  produce  hexatomic  alcohols; 
and  on  oxidation  they  yield  monocarboxylic  acids.  Their  alcoholic  hy- 
,  drogen  is  replaceable  by  certain  metals  with  formation  of  sacchar- 
ates,  corresponding  to  the  alcoholates  (p.  244).  With  acids  they 
yield  esters.  They  form  osazones  with  phenylhydrazin.  Some  are 
very  prone  to  alcoholic  fermentation:  C6Hi2O6=2C2H6O+2CO2,  while 
others  readily  undergo  lactic  fermentation :  CeH^Oe^CaHeOs.  Being 
polyatomic  alcohols,  the  hexoses  form  insoluble  benzoic  esters  when 
their  alkaline  solutions  are  shaken  with  benzoyl  chlorid  (p.  255). 

Of  the  described  hexoses,  mannose,  glucose,  gulose,  idose,  galac- 
tose  and  talose  are  aldoses;  fructose  and  sorbinose  are  ketoses. 

Optical  Activity. — All  of  the  hexoses  exist  in  three  isomerids, 
differing  from  each  other  in  their  action  upon  polarized  light.  One 
of  these  rotates  the  plane  of  polarization  to  the  right,  and  is  desig- 
nated as  the  dextro-,  or  d- compound;  another  is  laevogyrous  and  is 


266  MANUAL    OF    CHEMISTRY 

designated  as  the  laevo-,  or  1- compound,  while  the  third  is  inactive, 
and  is  distinguished  by  the  symbol  (d-H). 

Stereoisomerism,  or  Space  Isomerism.— The  graphic  formulae 
indicate  the  structure  of  the  molecule  only  partially;  they  show  that 
certain  atoms  in  the  molecule  are  attached  to  some  of  their  fellows 
more  closely  than  to  others,  but  they  give  no  indication  of  the  posi- 
tions which  the  atoms  occupy  in  space  with  regard  to  each  other. 

H\ 
The   expression      C — 0 — H,   the   most   completely  detailed   graphic 

H/  I 

representation  of  that  group,  indicates  at  the  most  that  the  two  hy- 
drogen atoms  are  attached  to  one  side  of  the  carbon  atom,  while  the 
hydroxyl  is  attached  to  another.  Stereochemistry  is  that  branch  of 
chemistry  treating  of  the  relations  of  the  atoms  to  each  other  in  space. 
It  has  been  greatly  developed  in  recent  years  and  affords,  among  other 
things,  the  first  rational  explanation  of  the  cause  of  the  differences  in 
the  optical  activity  of  the  hexoses,  as  well  as  of  lactic  and  tartaric 
acids,  and  of  many  other  substances. 

If  we  suppose  that  differences  in  the  relative  positions  which 
atoms  or  groups  attached  to  carbon  atoms  occupy  with  relation  to 
each  other  produce  different  compounds  (see  Place  Isomerism,  p.  290; 
Orientation,  p.  381);  and  if  we  also  suppose  that  the  four  valences 
of  the  carbon  atom  act  in  a  plane-,  and  at  right  angles  to  each  other,  a 
vast  number  of  space -isomerids  of  the  di-  and  poly -substituted  de- 
rivatives of  the  aliphatic  hydrocarbons  would  exist,  no  representatives 
of  which  are,  however,  known.  For  example,  marsh -gas  would  yield 
two  isomerids  of  each  of  the  types:  CH2X2,  CH2XY  and  CH(X)2Y, 
and  three  isomerids  of  the  type  CHXYZ,  in  which  X,  Y,  and  Z  rep- 
resent any  three  univalent  atoms  or  radicals,  thus: 

H  H  H  H  H  H 

Cl— C-C1,  Cl-C— H,    Br-C— Cl,  H— C— Cl,  Cl— C— Cl,  Cl— C— Br  ; 

H  Cl  H  Br  Br  Cl 

Type  CH2X2.  Type  CH2XY.  Type  CHX2Y. 

H  H  H 

Cl— C— I,  I— C— Br,  and  Bi--C— Cl. 

Br  Cl  I 

Type  CHXYZ. 

But  only  one  representative  of  each  of  these  types  is  known. 
Therefore  the  usual  graphic  representation  of  the  valences  of  the 
carbon  atom  as  above,  while  convenient,  is  not  spatially  consistent  with 
fact,  and  the  four  valences  of  the  carbon  atom  are  not  exerted  in 
one  plane. 

The  suggestion  of  Van't  Hoff  (following  the  somewhat  similar 


. 


ALDEHYDE- ALCOHOLS  —  KETONE- ALCOHOLS,  ETC. 


267 


B 


idea  of  Kekule)  that  the  valences  of  the  carbon  atom  are  represented 
by  considering  it  as  occupying  the  interior  of  a  regular  tetrahedron, 
the  solid  angles  of  which  indicate  the  direction  of  its  valences  (Fig. 
34,  A),  taken  in  connection  with  the  hypothesis  of  an  asymmetric 
carbon  atom,  affords  a  rational  explanation  of  the  facts  just  cited, 
and  of  the  differences  in  the  optical  properties  of  the  substances  men- 
tioned. 

Admitting  the  regular  tetrahedron  to  represent  the  arrangement  of 
the  valences  of  the  carbon  atom,  it  follows  that  all  carbon  atoms,  two 
of  whose  valences  are  satisfied 
by  the  same  kind  of  univalent 
atom  or  group,  and  the  other 
two  by  two  constant  but  dis- 
similar univalents,  must  be 
symmetrical.  The  two  similar 
univalents  must  occupy  the 
summits  at  the  extremities  of 
some  one  crest,  and  the  only 
possible  variation  in  arrange- 
ment of  the  other  two  is  in 
their  position  with  regard  to 
this  crest.  Thus  B  and  C, 
Fig.  34,  although  dissimilar  in 
the  position  in  which  they  are 
placed,  become  perfectly  sym- 
metrical when  either  one  is 
rotated  through  180  degrees. 
But  when  all  four  of  the  car- 
bon valences  are  satisfied  by 
different  univalents  two  ar- 
rangements are  possible,  pro- 
ducing two  molecular  groups 
which  are  unsymmetrical  in 
whatever  position  they  may  be 
placed.  Thus  D  and  E,  Fig. 


34,  are  unsymmetrical  in  the 
positions  in  which  they  are  re- 
presented, and  remain  so,  however  their  positions  may  be  changed. 
A  carbon  atom  attached  to  four  different  univalents  is  called  an 
asymmetric  carbon  atom.  In  graphic  formulae  asymmetric  carbon 
atoms  are  designated  by  the  italic  C,  or  by  an  asterisk,  C  *.  Sub- 
stances containing  an  asymmetric  carbon  atom  exist  in  two  oppo- 
sitely optically  active  modifications. 

The  structure  of  the  four  isomeric  tartaric  acids  (p.  295)  was  first 


FIG.  34. 


268  MANUAL    OP    CHEMISTRY 

explained  under  the  hypothesis  of  the  asymmetric  carbon  atom.  Let 
it  be  assumed  that  two  asymmetric  carbon  atoms,  with  their  attached 
groups  or  atoms,  exert  a  "directing  influence"  upon  each  other,  and 
that,  being  attached  to  each  other  at  one  point  only,  they  are  capable 
of  rotating  independently  about  a  common  axis  (a. a.  Fig.  34,  G) ,  such 
rotation  would  then  occur  in  obedience  to  the  directing  influence  until 
a  condition  of  equilibrium  is  reached,  in  which  position  the  atoms 
would  remain.  Assuming  this  position  to  be  that  shown  in  F,  G, 
and  H,  Fig.  34,  with  the  two  COOH  groups  in  like  relation,  then  the 
three  unsymmetrical  arrangements  shown  in  the  figure  are  possible. 
The  first  represents  the  structure  of  dextro-tartaric  acid,  G  that  of 
laevo-tartaric  acid,  and  H  that  of  meso-tartaric  acid,  while  racemic 
acid  is  a  combination  of  dextro-  and  laevo-tartaric  acids. 

The  tetrahedron  representation  of  the  carbon  valences  adapts  itself 
very  well  also  to  the  explanation  of  certain  isomerids  of  the  ethylene 
series,  in  which  two  carbon  atoms  are  doubly  linked  together.  In 
these  the  two  carbon  atoms  being  linked  together  at  two  points  (I 
and  K,  Fig.  34)  cannot  be  considered  as  being  capable  of  rotation, 
and,  if  the  two  other  valences  of  each  carbon  atom  are  satisfied  by 
the  same  two  dissimilar  univalents,  two  positions  are  possible:  I,  in 
which  the  like  univalents  are  directed  to  the  same  side,  called  the 
"plane  symmetrical  configuration,"  and  K,  in  which  they  are  directed 
towards  opposite  sides,  called  the  "axially  symmetrical  configura- 
tion." 

Mannose  is  obtained,  as  d-,  1-,  and  d-H,  mannoses  by  oxidation  of 
the  corresponding  mannitols. 

Glucose  —  Grape  Sugar  —  Dextrose  —  Liver  Sugar  —  Diabetic 
Sugar — d-Glucose  occurs  in  many  sweet  fruits  and  vegetable  juices, 
and  in  honey,  accompanied  by  fructose;  and,  in  the  animal  world,  in 
the  contents  of  the  intestine,  liver,  bile,  thymus,  heart,  lungs,  blood, 
and,  in  small  quantity,  in  the  urine.  Pathologically,  it  appears  in  the 
saliva,  perspiration,  faeces,  and,  in  largely  increased  amount,  in  the 
blood  and  urine  in  diabetes  mellitus.  It  is  produced  by  the  decompo- 
sition of  the  polysaccharids  and  of  many  of  the  glucosids,  and  is  manu- 
factured on  a  large  scale  by  the  action  of  boiling  dilute  H2SO4  upon 
starch.  The  commercial  product  so  obtained  is  either  an  amorphous, 
white  solid  (grape  sugar),  containing  about  60%  of  true  glucose, 
along  with  dextrins  and  the  unfermentable  isomaltose,  or  gallisin, 
Ci2H22On ;  or  a  thick,  colorless  syrup  (glucose),  containing,  be- 
sides the  above,  a  minute  quantity  of  a  nitrogenous  body  which 
exerts  a  solvent  action  upon  coagulated  albumin  at  the  body  tem- 
perature. 

d- Glucose  has  been  produced  synthetically  by  the  reduction  of  the 
lactone  of  d-gluconic  acid  (p.  294). 


I 


ALDEHYDE-ALCOHOLS  — KETONE-ALCOHOLS,  ETC.  269 

It  crystallizes  from  its  aqueous  solutions  at  the  ordinary  temper- 
ature with  difficulty  in  white,  opaque,  spheroidal  masses  containing 
lAq,  which  foise  at  86°  and  lose  the  Aq  at  110°.  From  its  concen- 
trated aqueous  solution  at  30°  to  35°,  or  from  its  alcoholic  solution  it 
crystallizes  in  hard,  anhydrous,  crystalline  crusts,  which  fuse  at  146°. 
It  is  soluble  in  all  proportions  in  hot  water,  is  very  soluble  in  cold 
water,  and  soluble  in  alcohol.  It  is  less  sweet  and  less  soluble  than 
cane  sugar.  Its  aqueous  solutions  are  dextrogyrous :  [a]D=H-52.60  in 
boiled  solutions.  Freshly  prepared  cold  aqueous  solutions  have 
nearly  double  that  rotary  power  at  first,  the  value  of  [a]  D  gradually 
falling  to  52.6°  in  about  twenty-four  hours.  Its  osazone,  d-glucosa- 
zone,  crystallizes  in  needles,  fusible  at  205°.  Its  solutions  dissolve 
baryta  and  lime,  with  which,  as  with  potash,  soda,  and  the  oxids  of 
Pb  and  Cu,  it  forms  saccharates. 

I -Glucose  is  formed  by  reduction  of  the  lactone  of  1-gluconic  acid. 
It  is  in  all  respects  similar  to  d- glucose  except  that  it  fuses  at  143°, 
and  its  solutions  are  laevogyrous  MD= — 51.4°. 

d-\-l- Glucose  is  formed  by  reduction  of  d+1-gluconic  lactone; 
or  by  union  of  d-  and  1- glucose.  Its  solutions  are  optically  inac- 
tive. 

Galactose  is  also  known  in  its  three  modifications.  d-Galactose 
is  produced  by  the  hydrolysis  of  milk  sugar  and  of  certain  gums.  It 
crystallizes  more  readily  than  glucose,  is  very  sparingly  soluble  in 
cold  alcohol,  has  a  specific  rotary  power  of  [a]D=+83.33°,  and  fuses 
at  160°.  By  reduction  it  yields  dulcite,  and  by  oxidation  galactonic 
acid,  CH2OH.  (CHOH)4.  COOH,  and  mucic  acid,  COOH.  (CHOH)4. 
COOH.  Cerebrose,  obtained  by  the  hydrolysis  of  cerebrin,  a  con- 
stituent of  nerve  tissue,  is  identical  with  galactose. 

Fructose,  a  ketohexose,  exists  in  the  three  modifications.  d-Fruc- 
tose — Lmvulose — Fruit  sugar — forms  the  uncrystallizable  portion  of 
the  sugar  of  fruits  and  of  honey,  in  which  it  is  associated  with  glu- 
cose; it  is  produced  artificially  by  the  prolonged  action  of  boiling 
water  upon  inulin,  a  polysaccharid ;  also,  along  with  an  equal  quan- 
tity of  glucose,  as  one  of  the  constituents  of  invert  sugar,  by  the 
decomposition  of  cane  sugar  ;  and  from  d-glucosazone.  It  crys- 
tallizes with  great  difficulty,  fuses  at  95°,  is  very  soluble  in  water, 
and  insoluble  in  absolute  alcohol.  Although  called  d -fructose,  be- 
cause of  its  formation  from  d-glncosazone,  it  is  strongly  laevo- 
rotary:  MD= — 71.4°.  It  is  less  readily  fermentable  than  glucose, 
which  it  equals  in  the  readiness  with  which  it  reduces  cupro- 
potassic  solutions.  With  phenylhydrazin  it  yields  d-glucosazone 
(p.  430). 

Sorbinose,  also  a  ketohexose,  occurs  in  the  berries  of  the  moun- 
tain ash.  It  does  not  ferment.  Its  osazone  fuses  at  164°. 


270  MANUAL    OP    CHEMISTRY 

DISACCHARIDS — SACCHAROBIOSES . 

Disaccharids  consist  of  two  molecules  of  monosaccharids,  united 
with  elimination  of  H2O.  So  far  as  is  known  they  are  all  derived 
from  the  hexoses,  and  their  formula  is  consequently  C^H^On.  They 
are  all  capable  of  yielding  two  hexose  molecules  by  hydrolysis: 
Ci2H22Oii+H2O=2C6Hi2O6,  a  change  which  is  called  " inversion."  The 
union  of  the  two  monosaccharid  molecules  is  either  through  the  alde- 
hyde, ketone,  or  alcoholic  groups.  Of  the  three  most  important  disac- 
charids,  saccharose,  lactose  and  maUose,  the  first  named  has  no  reduc- 
ing power,  and  yields  no  osazone  with  phenylhydrazin.  It  therefore 
contains  no  aldehyde  or  ketone  group.  When  heated  with  acetic 
anhydrid  to  160°  it  forms  an  octacetyl  ester,  Ci2Hi4O3(O.C2H3O)8.  It 
therefore  contains  eight  hydroxyls.  When  hydrolyzed  it  yields  d- glu- 
cose and  d-fructose  (laevogyratory).  From  the  above  facts  we  may 
infer  that  saccharose  is  derived  from  the  two  hexoses  named,  united 
through  the  aldehyde  and  ketone  groups,  a  constitution  which  may  be 
represented  by  the  formulae: 

CH2OH .  CO.(CHOH )  2 .  CHOH .  CH2OH  CHO .  ( CHOH )  4 .  CH2OH 

d-Fructose.  d-Glucose. 


CH2OH.CH.(CHOH)2.C.CH2OH.         CH.(CHOH)4.CH2 
Saccharose. 

Lactose  and  maltose  both  cause  reduction  and  yield  osazones.  On 
hydrolysis  the  former  yields  d- glucose  and  galactose,  and  the  latter 
only  d- glucose.  They  each  consequently  retain  an  aldehyde  (or 
ketone)  group,  and  their  constitution  may  probably  be  represented 
thus: 


r  CH2OH.CHOH.CH.(CHOH)2.CH.O.CH2.(CHOH)4.CHO         and 

/0\ 
CHO.(CHOH)4.CH2   CH2.(CHOH)4.CHO 

The  disaccharids  are  hydrolyzed  by  boiling  with  very  dilute  acids, 
or  even  with  water,  and  by  several  enzymes  such  as  diastase,  emulsin, 
invertin,  ptyalin,  trypsin  and  pepsin. 

Saccharose  —  Cane  Sugar  —  exists  in  many  roots,  fruits  and 
grasses,  and  is  produced  from  the  sugar-cane,  Bacclnarum  officinarum, 
sorghum,  Sorghum  saccharatum,  beet,  Beta  vulgaris,  and  sugar-maple, 
Acer  saccharinum. 

For  the  extraction  of  sugar  the  expressed  juice  is  heated  in  large 
pans  to  about  100°  (212°  F.);  milk  of  lime  is  added,  which  causes 


ALDEHYDE-ALCOHOLS  —  KETONE- ALCOHOLS,  ETC.  271 

the  precipitation  of  albumen,  wax,  calcic  phosphate,  etc.;  the  clear 
liquid  is  drawn  off,  and  "  delimed"  by  passing  a  current  of  CO2  through 
it;  the  clear  liquid  is  again  drawn  off  and  evaporated,  during  agita- 
tion, to  the  crystallizing  point;  the  product  is  drained,  leaving  what 
is  termed  raw  or  muscovado  sugar,  while  the  liquor  which  drains  off 
is  molasses.  The  sugar  so  obtained  is  purified  by  the  process  of 
"refining,"  which  consists  essentially  in  adding  to  the  raw  sugar,  in 
solution,  albumen  in  some  form,  which  is  then  coagulated;  filtering 
first  through  canvas,  afterward  through  animal  charcoal;  and  evapo- 
rating the  clear  liquid  in  "vacuum -pans,"  at  a  temperature  not  exceed- 
ing 72°  (161.6°  F.),  to  the  crystallizing  point.  The  product  is 
allowed  to  crystallize  in  earthen  moulds;  a  saturated  solution  of  pure 
sugar  is  poured  upon  the  crystalline  mass  in  order  to  displace  the 
uncrystallizable  sugar  which  still  remains,  and  the  loaf  is  finally  dried 
in  an  oven.  The  liquid  displaced  as  above  is  what  is  known  as  sugar- 
house  syrup. 

Pure  sugar  should  be  entirely  soluble  in  water;  the  solution  should 
not  turn  brown  when  warmed  with  dilute  potassium  hydroxid  solu- 
tion; should  not  reduce  Fehling's  solution,  and  should  give  no  pre- 
cipitate with  ammonium  oxalate. 

Beet-sugar  is  the  same  as  cane-sugar,  except  that,  as  usually  met 
with  in  commerce,  it  is  lighter,  bulk  for  bulk.  Sugar-candy,  or 
rock-candy,  is  cane-sugar  allowed  to  crystallize  slowly  from  a  concen- 
trated solution,  without  agitation.  Maple- sugar  is  a  partially  refined, 
but  not  decolorized  variety  of  cane-sugar. 

Saccharose  crystallizes  in  small,  white,  monoclinic  prisms;  or,  as 
sugar-candy,  in  large,  yellowish,  transparent  crystals;  sp.  gr.  1,606. 
It  is  very  soluble  in  water,  dissolving  in  about  one -third  its  weight 
of  cold  water,  and  more  abundantly  in  hot  water.  It  is  insoluble  in 
absolute  alcohol  or  ether,  and  its  solubility  in  water  is  progressively 
diminished  by  the  addition  of  alcohol.  Aqueous  solutions  of  cane- 
sugar  are  dextrogyrous,  [a]r>=-\-66.5° . 

When  saccharose  is  heated  to  160°  (320°  F.)  it  fuses,  and  the 
liquid,  on  cooling,  solidifies  to  a  yellow,  transparent,  amorphous  mass, 
known  as  barley- sugar ;  at  a  slightly  higher  temperature,  it  is  decom- 
posed into  glucose  and  laevulosan;  at  a  still  higher  temperature,  H^O 
is  given  off,  and  the  glucose  already  formed  is  converted  into  glu- 
cosan;  at  about  200°  (392°  F.)  the  evolution  of  H2O  is  more  abun- 
dant, and  there  remains  a  brown  material  known  as  caramel,  or 
burnt  sugar;  a  tasteless  substance,  insoluble  in  strong  alcohol,  but 
soluble  in  H^O,  or  in  aqueous  alcohol,  and  used  to  communicate  color 
to  spirits;  finally,  at  higher  temperatures,  methyl  hydrid  and  the  two 
oxids  of  carbon  are  given  off;  a  brown  oil,  acetone,  acetic  acid,  and 
aldehyde  distil  over;  and  a  carbonaceous  residue  remains. 


272  MANUAL    OF    CHEMISTRY 

If  saccharose  be  boiled  for  some  time  with  H2O,  it  is  converted 
into  inverted  sugar,  which  is  a  mixture  of  glucose  and  fructose: 
Ci2H220ii+H2O=C6Hi2O6H-C6Hi2O6.  With  a  solution  of  saccharose 
the  polarization  is  dextrogyrous,  but,  after  inversion,  it  becomes 
laevogyrous,  because  the  left-handed  action  of  the  molecule  of  fruc- 
tose produced,  MD=  —  71.4°,  is  only  partly  neutralized  by  the  right- 
handed  action  of  the  glucose,  [a]D=+52.6°.  This  inversion  of  cane 
sugar  is  utilized  in  the  testing  of  samples  of  sugar.  On  the  other 
hand,  it  is  to  avoid  its  occurrence,  and  the  consequent  loss  of  sugar, 
that  the  vacuum -pan  is  used  in  refining — its  object  being  to  remove 
the  H^O  at  a  low  temperature. 

With  potassium  chlorate,  sugar  forms  a  mixture  which  detonates 
when  subjected  to  shock,  and  which  deflagrates  when  moistened  with 
H2SO4.  Concentrated  H2SC>4  blackens  it.  Dilute  HNO3,  when  heated 
with  saccharose,  oxidizes  it  to  saccharic  and  oxalic  acids. 

When  moderately  heated  with  liquor  potassae,  cane-sugar  does  not 
turn  brown,  as  does  glucose;  but  by  long  ebullition  it  is  decomposed 
by  the  alkalies,  much  less  readily  than  glucose,  with  formation  of 
acids  of  the  fatty  series  and  oxalic  acid. 

With  the  bases,  saccharose  forms  definite  compounds  called  suc- 
rates  (improperly  saccharates,  a  name  belonging  to  the  salts  of  sac- 
charic acid).  With  Ca  it  forms  five  compounds.  Calcium  hydroxid 
dissolves  readily  in  solutions  of  sugar,  with  formation  of  a  Ca  com- 
pound, soluble  in  H2O,  containing  an  excess  of  sugar. 

During  the  process  of  digestion,  probably  in  the  small  intestine, 
cane-sugar  is  converted  into  glucose. 

Lactose — Milk  Sugar — Lactine— Saccharum  lactis  (U.  S.,  Br.) 
— occurs  in  the  milk  of  the  mammalia,  in  the  amniotic  fluid  of  cows, 
and  in  the  urine  of  women  towards  the  end  of  gestation  and  during 
lactation.  It  may  be  obtained  from  skim -milk  by  coagulating  the 
casein  with  a  small  quantity  of  H^SCU,  filtering,  evaporating,  redis- 
solving,  decolorizing  with  animal  charcoal,  and  recrystallizing. 

It  forms  prismatic  crystals;  sp.  gr.  1.53;  hard,  transparent, 
faintly  sweet,  soluble  in  6  parts  of  cold  and  2.5  parts  of  boiling 
EkO;  soluble  in  acetic  acid;  insoluble  in  alcohol  and  in  ether.  Its 
solutions  are  dextrogyrous  [a]D=-f52.5°.  The  crystals,  dried  at 
100°  (212°  F.),  contain  lAq,  which  they  lose  at  150°  (302°  F.). 

Lactose  is  not  altered  by  contact  with  air.  Heated  with  dilute  min- 
eral acids  or  with  strong  organic  acids,  it  is  converted  into  galactose. 
HNOa  oxidizes  it  to  mucic  and  oxalic  acids.  A  mixture  of  HNOs 
and  H2SO4  converts  it  into  an  explosive  nitro- compound.  With 
organic  acids  it  forms  esters.  With  soda,  potash  and  lime  it  forms 
compounds  similar  to  those  of  saccharose,  from  which  lactose  may  be 
recovered  by  neutralization,  unless  they  have  been  heated  to  100° 


ALDEH YDE- ALCOHOLS— KETONE- ALCOHOLS,  ETC.      273 

(212°F.),  at  which  temperature  they  are  decomposed.  It  reduces 
Fehling's  solution,  and  reacts  with  Trommer's  test.  Its  osazone  fuses 
at  200°  (392°  F.). 

In  the  presence  of  yeast,  lactose  is  capable  of  alcoholic  fermenta- 
tion, which  takes  place  slowly,  and,  as  it  appears,  without  previous 
transformation  of  the  lactose  into  either  glucose  or  galactose.  On 
contact  with  putrefying  proteins  it  enters  into  lactic  fermentation. 

The  average  proportion  of  lactose  in  different  milks  is  as  follows: 
Cow,  5.5  per  cent.;  mare,  5.5;  ass,  5.8;  human,  5.3;  sheep,  4.2; 
goat,  4.0.  It  is  converted  into  galactose  *by  the  pancreatic  secretion. 

Maltose — is  formed,  along  with  dextrins,  during  the  conversion 
of  starch,  or  of  glycogen,  into  sugar  by  the  action  of  diastase  (in 
malting  grain),  and  of  the  enzymes  of  the  saliva  and  the  pancreatic 
juice.  It  is  also  an  intermediate  product  in  the  hydrolysis  of  starch 
by  dilute  sulfuric  acid.  Maltose  crystallizes  in  hard,  white  needles 
aggregated  into  crusts.  It  is  less  soluble  in  alcohol  than  is  glucose, 
and  has  a  much  higher  dextrogyratory  power  [a]D=+137°.  It  re- 
duces Fehling's  solution.  It  is  hydrolyzed  by  boiling  with  dilute 
acids,  yielding  only  d- glucose.  It  is  fermentable.  Its  osazone  fuses 
as  206°.  Nitric  acid  oxidizes  it  to  d- saccharic  acid. 

Isomaltose — Gallisin — is  formed  along  with  maltose,  in  the  action 
of  diastase,  saliva,  or  pancreatic  juice,  or  of  boiling  dilute  acids,  on 
starch,  and  exists  in  beer  and  artificial  glucose.  It  is  also  formed  by 
the  prolonged  action  of  strong  HC1  on  d- glucose.  It  is  very  soluble  in 
water,  very  sweet,  and  does  not  ferment,  or  does  so  very  slowly.  Its 
osazone  forms  yellow  needles,  which  fuse  at  150°  (302°  F.),  and  are 
rather  soluble  in  hot  water. 


TRISACCHARIDS. 

Several  members  of  this  group  have  been  obtained  from  different 
vegetables.  They  have  the  formula  CisH^Oie.  The  best  known  are 
Raffinose,  or  Melitose,  which  occurs  in  eucalyptus -manna,  in  cotton 
seed,  and  in  beet-sugar  molasses;  and  Melecitose,  from  the  manna 
of  Pinus  larix. 

POLYSACCHARIDS. 

The  starches,  gums,  and  celluloses,  which  form  this  class,  have 
the  empirical  formula  CeHioC^,  but  their  molecular  weights  are  much 
greater  than  that  represented  by  that  formula.  They  are  very  widely 
distributed  in  vegetable  nature.  On  hydrolysis  they  are  finally  de- 
composed to  monosaccharids,  for  the  most  part  hexoses,  although 
some  of  the  gums  yield  pentoses. 
18 


274 


MANUAL    OP    CHEMISTRY 


Starch — Amylum — the  most  important  member  of  the  group,  ex- 
ists in  the  roots,  stems,  and  seeds  of  all  plants;  and  is  obtained  com- 
mercially from  rice,  potatoes,  and  maize.  It  is  a  white  powder,  con- 
sisting of  granules  which  are  round,  ovoid  or  irregular  in  outline, 
and,  in  some  cases,  marked  with  a  central  spot  or  line,  called  the 
hilum,  and  with  concentric  rings.  Differences  in  the  shape,  size  and 
markings  of  the  granules  are  utilized  to  identify  the  vegetable  from 


FIG.  35.    A,  wheat-starch;  B,  oat-starch;  (7,  maize-starch;  1},  potato-starch.    X  300  diameters. 

which  the  starch  was  obtained.  Some  of  the  commoner  forms  are 
shown  in  Fig.  35.  Air -dried  starch  contains  18%  of  water,  of  which 
it  loses  8%  in  vacuo,  and  the  remainder  only  at  145°  (293°  F.). 
Starch  is  insoluble  in  cold  water  and  in  alcohol.  If  15  to  20  parts 
of  E^O  be  gradually  heated  with  one  part  of  starch,  the  granules 
swell  at  about  55°  (131°  F.),  and  at  80°  (176°  F.)  they  have  lost 
their  structure,  have  swelled  to  thirty  times  their  original  volume, 
and  have  formed  a  homogeneous,  translucent,  gelatinous  mass,  com- 
monly known  as  starch  paste.  This  hydrated  starch  consists  of  an 


ALDEHYDE- ALCOHOLS  —  KETONE- ALCOHOLS,  ETC      275 

insoluble  portion,  starch  cellulose,  and  a  soluble  portion,  granulose, 
or  soluble  starch.  Granulose  forms  an  opalescent  solution  in  water, 
from  which  it  is  precipitated  as  a  white  powder  by  alcohol.  Its  solu- 
tions are  strongly  dextogyrous,  [a]D=-h207°  (about).  By  prolonged 
boiling  with  water,  or,  more  rapidly,  by  boiling  dilute  mineral  acids, 
or  by  the  action  of  diastatic  enzymes,  soluble  starch  is  converted  into 
dextrins,  maltose,  and  finally,  d-glucose.  Dry  heat  causes  the  starch 
granules  to  burst,  with  formation  of  dextrin.  A  dilute  solution  of 
iodin  produces  a  violet -blue  color  with  starch,  whether  dry,  hydrated, 
or  in  solution.  The  color  is  discharged  by  heat,  but  reappears  on 
cooling.  Concentrated  HNO3  dissolves  starch  in  the  cold,  forming  a 
nitro- product,  called  xylodin,  or  pyroxam,  which  is  insoluble  in  water, 
soluble  in  a  mixture  of  alcohol  and  ether,  and  explosive. 

Glycogen — Animal  Starch — occurs  in  the  liver,  the  placenta, 
white  blood  corpuscles,  pus  cells,  young  cartilage  cells,  muscular 
tissue  and  many  embryonic  tissues,  also  in  many  molluscs.  It  is 
best  obtained  from  liver  tissue,  by  extraction  with  hot  water  and 
precipitation  by  alcohol,  after  separation  of  protein  bodies  by  potas- 
sium iodhydrargyrate  and  acetic  acid.  It  is  a  snow-white,  floury 
powder,  amorphous,  tasteless,  and  odorless;  soluble  in  water,  forming 
an  opalescent  solution,  insoluble  in  alcohol  or  ether.  Its  solutions 
are  strongly  dextrogyrous,  [a]D=+196.6°.  Glycogen  is  converted 
into  dextrins,  maltose,  and,  ultimately,  d-glucose  by  the  action  of 
boiling  dilute  acids,  and  by  the  salivary,  pancreatic  and  hepatic  dias- 
tatic enzymes.  Glycogen  is  colored  wine -red  by  iodin,  the  color  being 
discharged  by  heat  and  returning  on  cooling.  Its  solutions  dissolve, 
but  do  not  reduce  cupric  hydroxid. 

Other  starches  are:  Paramylum,  occurring  in  certain  infusoria; 
Lichenin,  in  lichens  and  mosses;  and  Inulin,  in  the  roots  of  dahlia, 
chicory  and  other  plants. 

Gums — are  amorphous,  translucent  substances  occurring  in  many 
plants.  They  are  insoluble  in  alcohol  and  in  ether.  With  water  some 
of  them,  the  true  gums,  form  clear  solutions;  while  others,  the  vega- 
table  mucilages,  swell  up  to  sticky  masses  which  cannot  be  filtered 
through  paper.  On  boiling  with  dilute  H2SO4  the  gums  yield 
d-glucose,  galactose,  or  1-arabinose.  Nitric  acid  oxidizes  them  to 
mucic,  oxalic  and  saccharic  acids. 

The  commoner  members  of  the  group  are :  Arabin,  the  chief  con- 
stituent of  gum  arabic  (acacia)  and  gum  Senegal;  and  Bassorin,  the 
chief  ingredient  of  gum  tragacanth,  Bassora  gum,  and  plum  and 
cherry  gums. 

Dextrin — British  gum — a  substance  resembling  gum  arabic  in 
appearance  and  in  many  properties,  is  obtained  by  one  of  three 
methods  :  (1)  by  subjecting  starch  to  a  dry  heat  of  175°  (347°  F.) ; 


276  MANUAL    OF    CHEMISTRY 

(2)  by  heating  starch  with  dilute  H2S04  to  90°  (194°  F.)  until  a  drop 
of  the  liquid  gives  only  a  wine -red  color  with  iodin;  neutralizing  with 
chalk,  filtering,  concentrating,  precipitating  with  alcohol;  (3)  by  the 
action  of  diastase  (infusion  of  malt)  upon  hydra  ted  starch.  As  soon 
as  the  starch  is  dissolved  the  liquid  must  be  rapidly  heated  to  boiling 
to  prevent  saccharification. 

Commercial  dextrin  is  a  colorless,  or  yellowish,  amorphous  pow- 
der, soluble  in  EbO  in  all  proportions,  forming  mucilaginous  liquids. 
When  obtained  by  evaporation  of  its  solution,  it  forms  masses  re- 
sembling gum  arabic  in  appearance.  Its  solutions  are  dextrogyrous, 
and  reduce  cupro-potassic  solutions  under  the  influence  of  heat,  to 
amounts  varying  with  the  method  of  formation  of  the  sample.  It  is 
colored  wine -red  by  iodin.  It  is  extensively  used  as  a  substitute  for 
gum  acacia. 

By  the  action  of  diastase  upon  starch,  four  dextrins  are  produced: 
(1)  Erythrodextrin,  which  is  colored  red  by  iodin,  and  which  is 
easily  attacked  by  diastase;  (2)  Achroodextrin  <*,  not  colored  by 
iodin ;  partially  converted  into  sugar  by  diastase ;  rotary  power 
[a]D=+2100;  reducing  power  (glucose=100)  =12  ;  (3)  Achroo- 
dextrin /?,  not  colored  by  iodin,  nor  decomposable  in  twenty -four 
hours  by  diastase;  rotary  power +190°;  reducing  power=12;  (4) 
Achroodextrin  y,  not  colored  by  iodin,  nor  decomposed  by  diastase; 
slowly  converted  into  glucose  by  dilute  E^SCX  ;  rotary  power  = 
+150°;  reducing  power=28. 

An  explanation  of  this  series  of  transformations  has  been  sug- 
gested in  the  supposition  that  the  molecule  of  starch  consists  of 
50(Ci2H2oOio)  ;  that  this  is  first  converted  into  soluble  starch 
10(Ci2H2oOio) ;  and  that  this  is  then  converted  into  the  different 
forms  of  dextrin  by  a  series  of  hydrations  attended  by  simultaneous 
formation  of  maltose,  of  which  the  final  result  might  be  represented 
by  the  equation: 

10(Ci2H20Oio)  +  8(H20)  =  2(C12H20010)  +  8(C12H22On) 
Soluble  starch.  Water.  Achroodextrin.  Maltose. 

Cellulose—  Cellulin— forms  the  basis  of  all  vegetable  tissues.  It 
exists,  almost  pure,  in  the  pith  of  elder  and  of  other  plants,  in  the 
purer,  unsized  papers,  in  cotton,  and  in  the  silky  appendages  of  cer- 
tain seeds.  Cotton,  freed  from  extraneous  matter  by  boiling  with 
KHO  and  afterwards  with  dilute  HC1,  yields  pure  cellulose  (absorbent 
cotton).  It  is  white,  has  the  shape  of  the  fiber  from  which  it  was 
derived,  is  insoluble  in  the  usual  solvents,  but  soluble  in  the  dark  blue 
liquid  formed  by  dissolving  copper  in  ammonia  in  contact  with  air. 

Vegetable  parchment — Parchment  paper — is  obtained  by  dip- 
ping unsized  paper  for  an  instant  in  H2SO4,  diluted  with  an  equal 


CARBOXYLIC   ACIDS  277 

volume  of  H^O,  washing  thoroughly,  and  drying.  It  is  a  tough  ma- 
terial resembling  animal  parchment. 

Gun-cotton — Pyroxylin — is  obtained  by  dipping  pure  cotton  in  a 
cold  mixture  of  one  part  of  HNOa  and  two -thirds  of  H2SO4  for  from 
three  to  ten  minutes,  washing  thoroughly,  and  drying.  It  consists 
of  hexanitrocellulose,  CtaHuCO.NC^JeO^  is  violently  explosive,  and  is 
insoluble  in  a  mixture  of  alcohol  and  ether. 

Soluble  pyroxylin — is  obtained  by  acting  on  cotton  with  a  warm 
mixture  of  twenty  parts  of  nitre  and  thirty  parts  of  concentrated 
H2SO4,  washing  and  drying.  It  consists  of  penta-  and  tetra-nitro- 
cellulose,  is  soluble  in  a  mixture  of  alcohol  and  ether,  and  is  used  in 
the  preparation  of  collodion.  Explosive  gelatin,  or  smokeless  pow- 
der, is  produced  by  dissolving  nitro-glycerol  in  an  equal  part  of  col- 
lodion. Celluloid  is  a  mixture  of  gun-cotton  and  camphor,  combined 
by  pressure. 

CARBOXYLIC  ACIDS. 

These  compounds  are  the  fourth  products  of  oxidation  of  the 
paraffins  (p.  238),  and  contain  the  characterizing  group  of  atoms 
O:C.OH  (carboxyl).  They  are  either  pure  acids,  containing  only 
the  carboxyl  and  hydrocarbon  groups;  or  alcohol -acids,  containing 
also  the  groups  CH2OH,  CHOH  or  COH;  or  aldehyde -acids,  contain- 
ing CHO;  or  ketone- acids,  containing  CO;  or  of  still  more  complex 
function,  containing  two  or  more  of  the  above  groups. 

The  most  important  of  the  pure  acids  are  those  of  the  acetic 
(C«H2«O2),  and  oxalic  (CnH2«-2O4)  series,  the  former  of  which  are 
monobasic,  the  latter  dibasic.  Other  pure  acids  of  higher  basicity  are 
also  known  in  which  the  carboxyl  groups  are  substituted  for  hydro- 
gen atoms  in  the  hydrocarbon.  The  following  are  examples  of  such 
acids  : 

CH2.COOH  CH:(COOH), 

I  CH:(COOH)2  | 

CH.COOH  |  CH.COOH 

CH:(COOH)o  | 

CH2.COOH  CH:(COOH)2 

Tricarballylic  Dimalonic  Propenyl-pentacarboxylic 

acid.  acid.  acid. 


PARAFFIN  MONOCARBOXYLIC  ACIDS — VOLATILE   FATTY  ACIDS  —  ACETIC 
SERIES — SERIES    C*H2*O2 

The  lowest  terms  of  the  series  are  volatile  liquids,  the  highest  are 
solids  and  exist  in  their  glycerol  esters  in  the  fats ;  hence  the  name  of 
volatile  fatty  acids.  The  solid  acids,  the  tenth  and  higher  of  the 
series,  cannot  be  distilled  without  decomposition  except  in  superheated 
steam. 


278  MANUAL    OP    CHEMISTRY 

As  the  hydrocarbons  may  be  considered  as  the  hydrids  of  the 
alkyls  (p.  230),  and  the  alcohols  as  their  hydroxids  (p.  239),  so  the 
acids  may  be  considered  as  the  hydroxids  of  the  acidyls :  the  acid  or 
oxidized  radicals.  Thus  acetic  acid  is  acetyl  hydroxid,  (CH3.CO)OH. 

These  acids  may  be  obtained: 

(1)  By  oxidation  of  the  corresponding  alcohol  or  aldehyde:  C2H5.- 
CH2OH-hO2=C2H5.COOH-hH2O,  or  2CH3.CHO+O2=2CH3.COOH; 

(2)  By  decomposition  of  the  dicarboxylic  acids  (p.  285),  with  elimi- 
nation of  carbon  dioxid:  COOH.COOH=H.COOH+CO2,  and  COOH.- 
CH2.COOH=CH3.COOH-fCO2;    (3)  By  the  action  of   carbon  mon- 
oxid    upon    an    alkaline    hydroxid    or    alcoholate :     CO  +  NaHO  = 
H.COONa,  and  CO+C2H5.O.Na=C2H5.COONa;    (4)  From  the  acid 
nitrils,  or  cyanic  esters  (p.  340),  by  the  action  of  acids  or  alkalies  in 
the   presence   of  water:    HCN  +  H2O+KHO  =  H.COOK+NH3,    or 
CH3.CN+2H20+HC1=CH3.COOH+NH4C1.    This  constitutes  a  gen- 
eral method  for  the  introduction  of  carboxyl,  starting  from  the  haloid 
derivatives  of  the  hydrocarbon  (p.  233).     This  is  converted  into  the 
cyanid,  or  nitril  (p.  340)  by  heating  with  alcoholic  potassium  cyanid: 
BrCH2.CH3H-KCN=CNCH2.CH3-i-KBr,  or  BrCH2.CH2Br+2KCN= 
CN.CH2.CH2.CN-|-2KBr;   and  the  cyanid  is  then  converted  into  the 
acid  by  elimination  of  the  nitrogen  as  ammonia,  and  the  substitution 
of  OOH  in  its  place  by  the  action  of  acids  or  of  alkalies:   CN.CH2.- 
CH3+HC1+2H2O=COOH.CH2.CH3+NH4C1,  or    CN.CH2.CH2.CN+ 
2KHO+2H2O^COOK.CH2.CH2.COOK+2NH3  (pp.  285,288,  373). 

Formic  Acid — H.COOH — occurs  in  the  bodies  of  red  ants,  in  the 
stinging  hairs  of  certain  insects,  in  the  stinging  nettle,  in  the  leaves 
of  the  pine,  and  in  the  blood,  bile,  perspiration  and  muscular  fluid  of 
man. 

Although  it  is  the  first  member  of  this  series,  formic  acid  differs 
chemically  from  its  superior  homologues  in  several  respects:  (1)  It 
is  not  a  pure  acid,  but  both  aldehyde  and  acid,  the  single  carbon  atom 

/ /"\TT 

forming  part  of  both  groups:  0:C<^H   ;  (2)  It  produces  no  chlorid  or 
anhydrid  corresponding  to  those  of  its  superior  homologues  (p.  310) ; 

(3)  By  elimination  of  H2O  it  yields  carbon  monoxid:    H.COOH— 
H20=CO;   which  is  consequently  its  anhydrid  in  the  same  sense  that 
carbon  dioxid  is  that  of  the  true  carbonic  acid;   O:C:  (OH)2— H2O= 
C02. 

Formic  acid  is  produced  in  a  number  of  reactions ;  by  the  oxida- 
tion of  many  organic  substances:  sugar,  starch,  fibrin,  gelatin,  albu- 
min, etc.;  by  the  action  of  potash  upon  chloroform  and  kindred 
bodies;  by  the  action  of  mineral  acids  on  hydrocyanic  acid;  during 
the  fermentation  of  diabetic  urine;  by  the  direct  union  of  carbon 
monoxid  and  water;  by  the  decomposition  of  oxalic  acid  under  the 
influence  of  glycerol  at  about  100°  (212°  F.). 


CARBOXYLIC   ACIDS  279 

It  is  a  colorless  liquid,  having  an  acid  taste  and  a  penetrating 
odor;  it  acts  as  a  vesicant;  it  boils  at  100°  (212°  F.),  and,  when 
pure,  crystallizes  at  0°  (32°  F.).  It  is  miscible  with  EkO  in  all 
proportions. 

The  mineral  acids  decompose  it  into  H20  and  carbon  monoxid. 
Oxidizing  agents  convert  it  into  H2O  and  carbon  dioxid.  Alkaline 
hydroxids  decompose  it  with  formation  of  a  carbonate  and  liberation 
of  H.  It  acts  as  a  reducing  agent  with  the  salts  of  the  noble 
metals. 

Acetic  Acid — Acetyl  hydroxid — Hydrogen  acetate  —  Pyroligneous 
acid—Acidum  aceticum  (U.  S.;  Br.)— CH3.COOH— 60. 

It  is  formed— (1)  By  the  oxidation  of  alcohol:  CH3.CH2OH+ 
O2=CH3.COOH+H2O. 

(2)  By  the  dry  distillation  of  wood. 

(3)  By  the  decomposition  of  natural  acetates  by  mineral  acids. 

(4)  By  the  action  of  potash  in  fusion  on  sugar,  starch,  oxalic, 
tartaric,  citric  acids,  etc. 

(5)  By  the  decomposition  of  gelatin,  fibrin,  casein,  etc.,  by  IbSCU 
and  manganese  dioxid. 

(6)  By  the  action  of  carbon  dioxid  upon  sodium  methyl:   CO2+ 
NaCH3+C2H3O2Na ;    and   decomposition   of   the   sodium   acetate  so 
produced. 

The  acetic  acid  used  in  the  arts  and  in  pharmacy  is  prepared  by 
the  destructive  distillation  of  wood.  The  products  of  the  distilla- 
tion, which  vary  with  the  nature  of  the  wood  used,  are  numerous. 
Charcoal  remains  in  the  retort,  while  the  distilled  product  consists  of 
an  acid,  watery  liquid;  a  tarry  material;  and  gaseous  products.  The 
gases  are  carbon  dioxid,  carbon  monoxid,  and  hydrocarbons.  The 
tar  is  a  mixture  of  empyreumatic  oils,  hydrocarbons,  phenols,  acetic 
acid,  ammonium  acetate,  etc. 

The  acid  liquid  is  very  complex,  and  contains,  besides  acetic  acid, 
formic,  propionic,  butyric,  valerianic,  and  oxyphenic  acids,  acetone, 
naphthalene,  benzene,  toluene,  cumene,  creasote,  methyl  alcohol, 
methyl  acetate,  etc.  Partially  freed  from  tar  by  decantation,  it  still 
contains  about  20  per  cent,  of  tarry  and  oily  material,  and  about  4 
per  cent,  of  acetic  acid;  this  is  the  crude  pyroligneous  acid  of  com- 
merce. 

The  crude  product  is  subjected  to  a  first  purification  by  distilla- 
tion; the  first  portions  are  collected  separately  and  yield  methyl 
alcohol  (p.  241);  the  remainder  of  the  distillate  is  the  distilled  pyro- 
ligneous acid,  used  to  a  limited  extent  as  an  antiseptic,  but  princi- 
pally for  the  manufacture  of  acetic  acid  and  the  acetates.  Crude 
pyroligneous  acid  is  purified  by  conversion  into  sodium  acetate,  which, 
after  calcination,  is  decomposed  by  H2SO4,  and  the  liberated  acetic 


280  MANUAL    OF    CHEMISTRY 

acid  distilled  off.  The  product  so  obtained  is  a  solution  of  acetic 
acid  in  water,  containing  36  per  cent  of  true  acetic  acid,  and  being 
of  sp.  gr.  1.047. 

Pure  acetic  acid  known  as  glacial  acetic  acid,  acidum  aceticum 
glaciale  (U.  S.),  is  obtained  by  distilling  dry  sodium  acetate  with  a 
slight  excess  of  H2SO4. 

Acetic  acid  is  a  colorless  liquid.  Below  17°  (62.6°  F.),  when 
pure,  it  is  a  crystalline  solid.  It  boils  at  119°  (246.2°  F.);  sp.  gr. 
1.0801  at  0°  (32°  F.);  its  odor  is  penetrating  and  acid;  in  contact 
with  the  skin  it  destroys  the  epidermis  and  causes  vesication;  it  mixes 
with  EbO  in  all  proportions,  the  mixtures  being  less  in  volume  than 
the  sum  of  the  volumes  of  the  constituents.  The  sp.  gr.  of  the  mix- 
tures gradually  increase  up  to  that  containing  23  per  cent,  of  EkO, 
after  which  they  again  diminish,  and  all  the  mixtures  containing 
more  than  43  per  cent,  of  acid  are  of  higher  sp.  gr.  than  the  acid 
itself. 

Vapor  of  acetic  acid  burns  with  a  pale -blue  flame;  and  is  decom- 
posed at  a  red  heat.  It  only  decomposes  calcic  carbonate  in  the 
presence  of  EbO.  Hot  H^SO*  decomposes  and  blackens  it,  SC>2  and 
C02  being  given  off.  Under  ordinary  circumstances  Cl  acts  upon  it 
slowly,  more  actively  under  the  influence  of  sunlight,  to  produce 
monochloracetic  acid,  CEkCl.COOH ;  dichloracetic  acid,  CHCh.- 
COOH;  and  trichloracetic  acid,  CC13.CQOH.  The  last  named  is 
an  odorless,  acid,  strongly  vesicant,  crystalline  solid;  fuses  at  46° 
(114.8°  F.)  and  boils  at  195°-200°  (383°-392°  F.). 

Analytical  Characters. — (1)  Warmed  with  EbSCU  it  blackens. 
(2)  With  silver  nitrate:  a  white  crystalline  ppt.,  partly  dissolved  by 
heat;  no  reduction  of  Ag  on  boiling.  (3)  Heated  with  H2SO4  and 
C2HeO,  acetic  ether,  recognizable  by  its  odor,  is  given  off.  (4)  When 
an  acetate  is  calcined  with  a  small  quantity  of  As2Oa  the  foul  odor  of 
cacodyl  oxid  is  developed.  (5)  Neutral  solution  of  ferric  chlorid 
produces  in  neutral  solutions  of  acetates  a  deep-red  color,  which  turns 
yellow  on  addition  of  free  acid. 

Vinegar  is  an  acid  liquid  owing  its  acidity  to  acetic  acid,  and 
holding  certain  fixed  and  volatile  substances  in  solution.  It  is  ob- 
tained from  some  liquid  containing  10  per  cent,  or  less  of  alcohol, 
which  is  converted  into  acetic  acid  by  the  transferring  of  atmospheric 
oxygen  to  the  alcohol  during  the  process  of  nutrition  of  a  peculiar 
vegetable  ferment,  known  as  mycoderma  aceti,  or,  popularly,  as  mother 
of  vinegar.  The  liquids  from  which  vinegar  is  made  are  wine,  cider, 
and  beer,  to  which  dilute  alcohol,  obtained  by  fermenting  artificial 
glucose,  is  frequently  added;  the  most  esteemed  being  that  obtained 
from  white  wine.  Wine  vinegar  has  a  pleasant,  acid  taste  and  odor; 
it  consists  of  water,  acetic  acid  (about  5  per  cent.),  potassium  bitar- 


CAEBOXYLIC  ACIDS  281 

trate,  alcohol,  acetic  ether,  glucose,  malic  acid,  mineral  salts  present 
in  wine,  a  fermentable,  nitrogenized  substance,  coloring  matter, 
etc.  Sp.  gr.  1.020  to  1.025.  When  evaporated  it  yields  from  1.7  to 
2.4  per  cent,  of  solid  residue.  Vinegars  made  from  alcoholic  liquids 
other  than  wine  contain  no  potassium  bitar  trate,  contain  less  acetic 
acid,  and  have  not  the  aromatic  odor  of  wine  vinegar.  Cider  vinegar 
is  of  sp.  gr.  1.020;  is  yellowish,  has  an  odor  of  apples,  and  yields  1.5 
per  cent,  of  extract  on  evaporation.  Beer  vinegar  is  of  sp.  gr.  1.032; 
has  a  bitterish  flavor  and  an  odor  of  sour  beer;  it  leaves  6  per  cent, 
of  extract  on  evaporation.  Two  parts  of  good  wine  vinegar  neutralize 
10  parts  of  sodium  carbonate;  the  same  quantity  of  cider  vinegar,  3.5 
parts;  and  of  beer  vinegar,  2.5  parts  of  carbonate. 

Distilled  vinegar  is  prepared  by  distilling  vinegar  in  glass  vessels; 
it  contains  none  of  the  fixeci  ingredients  of  vinegar,  but  its  volatile 
constituents  (acetic  acid,  water,  alcohol,  acetic  ether,  odorous  prin- 
ciples, etc.),  and  a  small  quantity  of  aldehyde. 

When  dry  cupric  acetate  is  distilled,  a  blue,  strongly  acid 
liquid  passes  over;  this,  upon  rectification,  yields  a  colorless,  mobile 
liquid,  which  boils  at  56°  (132.8°  F.),  has  a  peculiar  odor,  and  is  a 
mixture  of  acetic  acid,  water,  and  acetone,  known  as  radical  vinegar. 

Toxicology. — When  taken  internally,  acetic  acid  and  vinegar  (the 
latter  in  doses  of  100  to  150  cc.)  act  as  irritants  and  corrosives,  caus- 
ing in  some  instances  perforation  of  the  stomach,  and  death  in  6-15 
hours.  Milk  of  magnesia  should  be  given  as  an  antidote,  with  a  view 
to  neutralizing  the  acid. 

Propionic  Acid — CH3.CH2.COOH — is  formed  by  the  action  of 
caustic  potash  upon  sugar,  starch,  gum,  and  ethyl  cyanid;  during 
fermentation,  vinous  or  acetic;  in  the  distillation  of  wood;  during  the 
putrefaction  of  peas,  beans,  etc.;  by  the  oxidation  of  normal  propylic 
alcohol,  etc.  It  is  best  prepared  by  heating  ethyl  cyanid  with  potash 
until  the  odor  of  the  ester  has  disappeared;  the  acid  is  then  liberated 
from  its  potassium  compound  by  H2SO4  and  purified. 

It  is  a  colorless  liquid,  sp.  gr.  0.996,  solidifies  at  —36.5°  (—33.7° 
F.),  boils  at  140°  (284°  F.),  mixes  with  water  and  alcohol  in  all  pro- 
portions, resembles  acetic  acid  in  odor  and  taste.  Its  salts  are  sol- 
uble and  crystallizable. 

Butyric  Acid— Propyl-formic  acid— CH3.CH2.CH2.COOH— has 
been  found  in  the  milk,  perspiration,  muscular  fluid,  the  juices  of 
the  spleen  and  of  other  glands,  the  urine,  contents  of  the  stomach 
and  large  intestines,  faBces,  and  guano;  in  certain  fruits,  in  yeast,  in 
the  products  of  decomposition  of  many  vegetable  substances;  and  in 
natural  waters;  in  fresh  butter  in  small  quantity,  more  abundantly  in 
that  which  is  rancid. 

It  is  formed  by  the  action  of  H2SO4  and  manganese  dioxid,  aided 


282  MANUAL    OF    CHEMISTEY 

by  heat,  upon  cheese,  starch,  gelatin,  etc. ;  during  the  combustion  of 
tobacco  (as  ammonium  butyrate) ;  by  the  action  of  HNO3  upon  oleic 
acid;  during  the  putrefaction  of  fibrin  and  other  proteins;  during  a 
peculiar  fermentation  of  glucose  and  starchy  material  in  the  presence 
of  casein  or  gluten.  This  fermentation,  known  as  the  butyric,  takes 
place  in  two  stages;  at  first  the  glucose  is  converted  into  lactic  acid: 
C6Hi2O6=2(C3H6O3) ;  and  this  in  turn  is  decomposed  into  butyric 
acid,  carbon  dioxid,  and  hydrogen:  2C3H6O3=C4H8O2-f  2CO2-f-2H2. 

Butyric  acid  is  obtained  from  the  animal  charcoal  which  has  been 
used  in  the  purification  of  glycerol,  in  which  it  exists  as  calcium 
butyrate.  It  is  also  formed  by  subjecting  to  fermentation  a  mixture 
composed  of  glucose,  water,  chalk,  and  cheese  or  gluten.  The  cal- 
cium butyrate  is  decomposed  by  H2SO4,  and  the  butyric  acid  is 
separated  by  distillation. 

Butyric  acid  is  a  colorless,  mobile  liquid,  having  a  disagreeable, 
persistent  odor  of  rancid  butter,  and  a  sharp,  acid  taste;  soluble  in 
water,  alcohol,  ether,  and  methyl  alcohol;  boils  at  164°  (327. 2°  F.), 
distilling  unchanged;  solidifies  in  a  mixture  of  solid  carbon  dioxid 
and  ether;  sp.  gr.  0.974  at  15°  (59°  F.) ;  a  good  solvent  of  fats. 

It  is  not  acted  upon  by  EkSCU  in  the  cold,  and  only  slightly  under 
the  influence  of  heat.  Nitric  acid  dissolves  it  unaltered  in  the  cold, 
but  on  the  application  of  heat,  oxidizes  it  to  succinic  acid.  Dry  Cl 
under  the  influence  of  sunlight,  and  Br  under  the  influence  of  heat 
and  pressure,  form  products  of  substitution  with  butyric  acid.  It 
readily  forms  esters  and  salts. 

Butyric  acid  is  formed  in  the  intestine,  by  the  process  of  fermen- 
tation mentioned  above,  at  the  expense  of  those  portions  of  the 
carbohydrate  elements  of  food  which  escape  absorption,  and  is  dis- 
charged with  the  faeces  as  ammonium  butyrate. 

Isobutyric  Acid— Isopropyl- formic  acid— cHa/CH.COOH— boils 
at  155°  (311°  F.),  has  been  found  in  human  fa3ces.  It  corresponds 
to  isobutyl  alcohol,  from  which  it  is  produced  by  oxidation. 

Valerianic  Acids — C^g.COOH — 102. — Corresponding  to  the  four 
primary  amylic  alcohols,  there  are  four  possible  amylic  or  valerian ic 
acids  : 

Normal  Valerianic  Acid — Butyl-formic  acid — Propyl-acetic  acid — 
is  obtained  by  the  oxidation  of  normal  amylic  alcohol.  It  is  an  oily 
liquid,  boils  at  185°  (365°F.),  and  has  an  odor  resembling  that  of 
butyric  acid. 

Ordinary  Valerianic  Acid — Delphinic  acid — Phocenic  acid — Iso- 
valeric  acid — Isopropyl -acetic  acid — Isobutyl-formic  acid — Acidum 
valerianicum  (Br.). — This  acid  exists  in  the  oil  of  the  porpoise,  and 
in  valerian  root  and  in  angelica  root.  It  is  formed  during  putrid 
fermentation  or  oxidation  of  proteins.  It  occurs  in  the  urine  and 


CAEBOXYLIC  ACIDS  283 

faeces  in  typhus,  variola,  and  acute  atrophy  of  the  liver.  It  is  also 
formed  in  a  variety  of  chemical  reactions,  and  notably  by  the  oxida- 
tion of  amylic  alcohol. 

The  ordinary  valerianic  acid  is  an  oily,  colorless  liquid,  having  an 
odor  of  old  cheese,  and  a  sharp,  acrid  taste.  It  solidifies  at  — 51° 
(—59.8°  F.);  boils  at  173°-175°  (343.4°-347°  F.);  sp.  gr.  0.9343- 
0.9465  at  20°  (68°  F.);  burns  with  a  white,  smoky  flame.  It  dis- 
solves in  30  parts  of  water,  and  in  alcohol  and  ether  in  all  proportions. 
It  dissolves  phosphorus,  camphor  and  certain  resins. 

Methyl-ethyl-acetic  Acid— boils  at  175°  (347°  F.).  It  contains 
an  asymmetric  carbon  atom  and  exists  in  two  optically  opposed  modi- 
fications (p.  265). 

Trimethyl-acetic  Acid  —  Pivalic  acid  —  is  a  crystalline  solid, 
which  fuses  at  35.5°  (96°  F.)  and  boils  at  163.7°  (326.7°  F.);  spar- 
ingly soluble  in  EbO;  obtained  by  the  action  of  mercuric  cyanid 
upon  tertiary  butyl  iodid. 

Caproic  Acids — Hexylic  acids— C5Hn.COOH  — 116. — There  exist 
seven  isomeres  having  the  composition  indicated  above,  some  of  which 
have  been  prepared  from  butter,  cocoa -oil  and  cheese,  and  by  decom- 
position of  amyl  cyanid,  or  by  oxidation  of  hexyl  alcohol. 

The  acid  obtained  from  butter,  in  which  it  exists  as  a  glyceric 
ester,  is  a  colorless,  oily  liquid,  boils  at  205°  (401°  F.) ;  sp.  gr.  0.931 
at  15°  (59°  F.) ;  has  an  odor  of  perspiration  and  a  sharp,  acid  taste; 
is  very  sparingly  soluble  in  water,  but  soluble  in  alcohol.  It  is  the 
normal  hexylic  acid:  CH3.(CH2)4.COOH. 

CEnanthylic  Acid — Heptylic  acid — C6Hi3.COOH— 130— exists  in 
spirits  distilled  from  rice  and  maize,  and  is  formed  by  the  action  of 
HNOs  on  fatty  substances,  especially  castor -oil.  It  is  a  colorless  oil; 
sp.  gr.  0.9167;  boils  at  212°  (413.6°  F.). 

Caprylic  Acid—  Octylic  acid  —  C7Hi5. COOH  — 144  —  accompanies 
caproic  acid  in  butter,  cocoa-oil,  etc.  It  is  a  solid;  fuses  at  15°  (59° 
F.) ;  boils  at  236°  (457°  F.) ;  almost  insoluble  in  H2O. 

Pelargonic  Acid — Nonylic  acid — CsHiT.COOH — 158. — A  colorless 
oil,  solid  below  10°  (50°  F.) ;  boils  at  260°  (500°  F.) ;  exists  in  oil  of 
geranium,  and  is  formed  by  the  action  of  HNOs  on  oil  of  rue. 

Capric  Acid—Decylic  Acid— CgHig-COOH — 172— exists  in  butter, 
cocoa-oil,  etc.,  associated  with  caproic  and  caprylic  acids  in  their 
glyceric  esters,  and  in  the  residues  of  distillation  of  Scotch  whisky,  as 
amyl  caprate.  It  is  a  white,  crystalline  solid;  melts  at  27.5°  (81.5° 
F.);  boils  at  273°  (523.4°  F.). 

Laurie  Acid  —  Laurostearic  acid—  CiiHw. COOH— 200— is  a  solid, 
fusible  at  43.5°  (110.3°  F.);  obtained  from  laurel  berries,  cocoa- 
butter  and  other  vegetable  fats. 

Myristic  Acid— Ci3H27.COOH— 228.—  A  crystalline  solid,  fusible 


281  MANUAL    OF    CHEMISTRY 

at  54°  (129.2°  F.) ;  existing  in  many  vegetable  oils,  cow's  butter  and 
spermaceti. 

Palmitic  Acid— Ethalic  acid^C^Usi.COOR— 256— exists  in  palm- 
oil,  in  combination  when  the  oil  is  fresh,  and  free  when  the  oil  is  old; 
it  also  enters  into  the  composition  of  nearly  all  animal  and  vegetable 
fats.  It  is  obtained  from  the  fats,  palm-oil,  etc.,  by  saponification 
with  caustic  potash  and  subsequent  decomposition  of  the  soap  by  a 
strong  acid.  It  is  also  formed  by  the  action  of  caustic  potash  in  fu- 
sion upon  cetyl  alcohol  (ethal),  and  by  the  action  of  the  same  reagent 
upon  oleic  acid. 

Palmitic  acid  is  a  white,  crystalline  solid;  odorless,  tasteless; 
lighter  than  EbO,  in  which  it  is  insoluble;  quite  soluble  in  alcohol 
and  in  ether;  fuses  at  62°  (143.6°  F.) ;  distils  unchanged  with  vapor 
of  water. 

Margaric  Acid — CieHas.COOH — 270 — formerly  supposed  to  exist 
as  a  glycerid  in  all  fats,  solid  and  liquid.  What  had  been  taken  for 
margaric  acid  was  a  mixture  of  90  per  cent,  of  palmitic  and  10  per 
cent,  of  stearic  acid.  It  is  obtained  by  the  action  of  potassium  hy- 
droxid  upon  cetyl  cyanid,  as  a  white,  crystalline  body;  fusible  at 
59.9°  (140°  F.). 

Stearic  Acid — CnHss.COOH  —  284  —  exists  as  a  glycerid  in  all 
solid  fats  and  in  many  oils,  and  also  free  to  a  limited  extent. 

To  obtain  it  pure  the  fat  is  saponified  with  an  alkali,  and  the  soap 
decomposed  by  HC1;  the  mixture  of  fatty  acids  is  dissolved  in  a  large 
quantity  of  alcohol,  and  the  boiling  solution  partly  precipitated  by 
the  addition  of  a  concentrated  solution  of  barium  acetate.  The  pre- 
cipitate is  collected,  washed  and  decomposed  by  HC1;  the  stearic  acid 
which  separates  is  washed  and  recrystallized  from  alcohol.  The  pro- 
cess is  repeated  until  the  product  fuses  at  70°  (158°  F.).  Stearic 
acid  is  formed  from  oleic  acid  (p.  374)  by  the  action  of  iodin  under 
pressure  at  270°-280°  (518°-536°  F.). 

Pure  stearic  acid  is  a  colorless,  odorless,  tasteless  solid;  fusible  at 
70°  (158°  F.) ;  unctuous  to  the  touch;  insoluble  in  H2O,  very  soluble 
in  alcohol  and  in  ether.  The  alkaline  stearates  are  soluble  in  H^Oj 
those  of  Ca,  Ba,  and  Pb  are  insoluble. 

Stearic  and  palmitic  acids  exist  free  in  the  intestine  during 
the  digestion  of  fats,  a  portion  of  which  is  decomposed  by  the 
action  of  the  pancreatic  secretion  into  fatty  acids  and  glycerol. 
The  same  decomposition  also  occurs  in  the  presence  of  putrefying 
proteins. 

Arachic  Acid — CigHsg.COOH — 312 — exists  as  a  glycerid  in  peanut 
oil  (now  largely  used  as  a  substitute  for  olive  oil),  in  oil  of  ben,  and 
in  small  quantity  in  butter.  It  is  a  crystalline  solid,  which  melts  at 
75° 


CARBOXYLIC  ACIDS  285 


PARAFFIN    DICAEBOXYLIC    ACIDS  —OXALIC    SERIES  —  CnH2«-2O4. 

These  acids  are  derivable  from  the  paraffins  by  oxidation  of  two 
groups,  or  from  the  diprimary  alcohols  by  oxidation  of  the 
CH2OH  groups  (pp.  238,  251).  They  contain  two  carboxyl  groups 
and  are  therefore  dibasic.  But  one  acid  is  possibly  derivable  from 
ethane  (oxalic  acid),  and  from  propane  (malonic  acid).  From  the 
two  butanes  two  acids  are  derivable;  from  the  three  pentanes  four 
acids,  and  from  the  five  hexanes  nine  acids;  all  of  which  are  known. 
The  molecular  structure  of  the  acids  derivable  from  the  butanes  and 
pentanes  are  shown  in  the  following  formulae  : 

CH3\ 

CH3.CH2.CH2.CH3  CH3-CH 

CH3/ 

Butane.  Isobutane. 

COOH.CH2.CH2.COOH  COOH\ 

COOH—  CH 

CH3/ 
Succinic  acid.  tsosuccinic  acid. 

CH3.CH2.CH2.CH2.CH3        (CH3)2  :CH.CH2.CH3        (CH3)4  :  :C 

Normal  Pentane.  Dimethyl-ethyl  Methane.         Tetramethyl  Methane. 

COOH.(CH2)3.COOH  (COOH)2:CH.CH2.CH3     (COOH)2:C:(CH3)2 

Glutaric  Acid.  Ethyl-malonic  Acid.  Dimethyl-malonic  Acid. 


Methyl-succinie  Acid. 

The  acids  of  this  series  may  be  obtained:  (1)  By  the  oxidation  of 
the  corresponding  diprimary  alcohols  (p.  251),  dialdehydes  (p.  261), 
primary  oxyaldehydes  -  (  p.  263),  primary  oxy  acids  (p.  289),  aldehyde 
acids  (p.  297),  paraffin  monocarboxylic  acids  (p.  277),  olefin  mono- 
carboxylic  acids  (p.  373),  or  paraffins  (p.  238). 

(2)  By  the  reduction  of  the  olefin  dicarboxylic  acids  (p.  375). 

(3)  By  the  action  of  silver  upon    the  monoiodo  or  monobromo 
fatty  acids:  2BrCH2.COOH+2Ag=2AgBr+COOH.CH2.CH2.COOH. 

(4)  By  the  action  of  acids  or  alkalies  upon  the  cyano  fatty  acids: 
CN.CH2.COOH+2H2O=:NH3+COOH.CH2.COOH;   or  upon   the  di- 
cyanids:    CN.CH2.CH2.CN+4H2O  =  2NH3+COOH.CH2.CH2.COOH. 
(p.  278). 

The  action  of  heat  upon  these  acids  and  their  salts  differs  accord- 
ing to  the  attachment  of  the  carboxyl  groups.  (1)  Oxalic  acid  and 
acids  in  which  the  two  carboxyls  are  attached  to  the  same  carbon 
atom  are  either  decomposed  into  the  two  oxids  of  carbon  and  water: 
COOH.COOH==CO2-fCO+H2O;  or  into  carbon  dioxid  and  a  fatty 
acid:  COOH.COOH=CO2+H.COOH. 

(2)  When  the  two  carboxyls  are  attached  to  neighboring  carbon 
atoms  the  acids  are  decomposed  into  water  and  an  anhydrid  (p.  310)  : 


286  MANUAL    OF    CHEMISTRY 

CH2.CO\ 

COOH.CH2.CH2.COOH=H2O+  I  O  .  3).     When  the  carboxyls 

CH2.CO/ 

are  attached  to  remote  carbon  atoms  their  calcium  salts  are  converted 
by  heat  into  cyclic  ketones  and  carbonate  : 


Oxalic  Acid—  COOH.COOH—  90—  C2H4O2,2Aq—  126—  does  not 
occur  free  in  nature,  but  in  the  oxalates  of  K,  Na,  Ca,  Mg,  and  Fe  in 
the  juices  of  many  plants:  sorrel,  rhubarb,  cinchona,  oak,  etc.;  as  a 
native  ferrous  oxalate;  and  in  small  quantity  in  human  urine.  It  is 
prepared  artificially  by  oxidizing  sugar  or  starch  by  HNOs,  or  by  the 
action  of  an  alkaline  hydroxid  in  fusion  upon  sawdust.  The  soluble 
alkaline  oxalate  obtained  by  the  latter  method  is  converted  into  the 
insoluble  Ca  or  Pb  salt,  which  is  washed  and  decomposed  by  an 
equivalent  quantity  of  H2SO4  or  H2S  ;  and  the  liberated  acid  purified 
by  recrystallization. 

Oxalic  acid  is  also  formed  by  the  oxidation  of  many  organic 
substances:  alcohol,  glycol,  sugar,  etc.;  by  the  action  of  potash  in 
fusion  upon  the  alkaline  formates;  and  by  the  action  of  K  or  Na 
upon  CO2. 

It  crystallizes  in  transparent  prisms,  containing  2  Aq,  which 
effloresce  on  exposure  to  air,  and  lose  their  Aq  slowly  but  completely 
at  100°  (212°  F.),  or  in  a  dry  vacuum.  It  fuses  at  98°  (208.4°  F.) 
in  its  Aq;  at  110°-132°  (230°-269.6°  F.)  it  sublimes  in  the  anhy- 
drous form,  while  a  portion  is  decomposed;  above  160°  (320°  F.) 
the  decomposition  is  more  extensive;  H2O,  C02,  CO,  and  formic  acid 
are  produced,  while  a  portion  of  the  acid  is  sublimed  unchanged.  It 
dissolves  in  15.5  parts  of  water  at  10°  (50°  F.);  the  presence  of 
HNOa  increases  its  solubility.  It  is  quite  soluble  in  alcohol.  It  has 
a  sharp  taste  and  an  acid  reaction  in  solution. 

Oxalic  acid  is  readily  oxidized;  in  watery  solution  it  is  converted 
into  CO2  and  H2O,  slowly  by  simple  exposure  to  air,  more  rapidly  in 
the  presence  of  platinum-black  or  of  the  salts  of  platinum  and  gold, 
under  the  influence  of  sunlight,  or  when  heated  with  HNOs,  mangan- 
ese dioxid,  chromic  acid,  Br,  Cl,  or  hypochlorous  acid.  Its  oxidation, 
when  it  is  triturated  dry  with  lead  dioxid,  is  sufficiently  active  to  heat 
the  mass  to  redness.  H2S04,  HsPO4  and  other  dehydrating  agents 
decompose  it  into  H2O,  CO  and  CO2. 

Analytical  Characters.  —  (1)  In  neutral  or  alkaline  solution:  a 
white  ppt.  with  a  solution  of  Ca  salt.  (2)  Silver  nitrate:  a  white 
ppt.,  soluble  in  HNO3,  and  in  NH4HO.  The  ppt.  does  not  darken 
when  the  fluid  is  boiled,  but  when  dried  and  heated  on  platinum  foil, 
it  explodes.  (3)  Lead  acetate,  in  solutions  not  too  dilute:  a  white 
ppt.,  soluble  in  HNOa,  insoluble  in  acetic  acid. 


CAEBOXYLIC   ACIDS  287 

Toxicology. — Although  certain  oxalates  are  constant  constituents 
of  vegetable  food  and  of  the  human  body,  the  acid  itself,  as  well  as 
monopotassic  oxalate,  is  a  violent  poison  when  taken  internally,  act- 
ing both  locally  as  a  corrosive  upon  the  tissues  with  which  it  comes 
in  contact  and  as  a  true  poison,  the  predominance  of  either  action 
depending  upon  the  concentration  of  the  solution.  Dilute  solutions 
may  produce  death  without  pain  or  vomiting,  and  after  symptoms 
resembling  those  of  narcotic  poisoning.  Death  has  followed  a  dose 
of  4  gm.  of  the  solid  acid,  and  recovery  a  dose  of  30  gm.  in  solution. 
When  death  occurs,  it  may  be  almost  instantaneously,  usually  within 
half  an  hour;  sometimes  after  weeks  or  months,  from  secondary 
causes. 

The  treatment,  which  must  be  as  expeditious  as  possible,  consists 
in  the  administration,  first,  of  lime  or  magnesia,  or  a  soluble  salt  of 
Ca  or  Mg,  suspended  or  dissolved  in  a  small  quantity  of  IbO  or  mu- 
cilaginous fluid;  afterward,  if  vomiting  have  not  occurred  sponta- 
neously, and  if  the  symptoms  of  corrosion  have  not  been  severe,  an 
emetic  may  be  given.  The  alkaline  carbonates  are  of  no  value  in 
cases  of  oxalic- acid  poisoning,  as  the  oxalates  which  they  form  are 
soluble  and  almost  as  poisonous  as  the  acid  itself.  The  ingestion  of 
water,  or  the  administration  of  warm  water  as  an  emetic,  is  contra- 
indicated  when  the  poison  has  been  taken  in  the  solid  form  (or  where 
doubt  exists  as  to  what  form  it  was  taken  in) ,  as  they  dissolve,  and 
thus  favor  the  absorption  of  the  poison. 

Analysis. — In  fatal  cases  of  poisoning  by  oxalic  acid  the  contents 
of  the  stomach  are  sometimes  strongly  acid  in  reaction;  more  usually, 
owing  to  the  administration  of  antidotes,  neutral,  or  even  alkaline. 
In  a  systematic  analysis  the  poison  is  to  be  sought  for  in  the  residue 
of  the  portion  examined  for  prussic  acid  and  phosphorus;  or,  if  the 
examination  for  those  substances  be  omitted,  in  the  ether -extract  from 
the  acid  solution  in  the  process  for  alkaloids.  If  oxalic  acid  alone  is  to 
be  sought  for,  the  contents  of  the  stomach,  or  other  substances  if  acid, 
are  extracted  with  water,  the  liquid  filtered,  the  filtrate  evaporated, 
the  residue  extracted  with  alcohol,  the  alcoholic  fluid  evaporated,  the 
residue  redissolved  in  water  (solution  No.  1).  The  portion  undis- 
solved  by  alcohol  is  extracted  with  alcohol  acidulated  with  hydro- 
chloric acid,  the  solution  evaporated  after  filtration,  the  residue  dis- 
solved in  water  (solution  No.  2).  Solution  No.  1  contains  any  oxalic 
acid  which  may  have  existed  free  in  the  substances  examined;  No.  2 
that  which  existed  in  the  form  of  soluble  oxalates.  If  lime  or  mag- 
nesia have  been  administered  as  an  antidote,  the  substances  must  be 
boiled  for  an  hour  or  two  with  potassium  carbonate  (not  the  hy- 
droxid),  filtered,  and  the  filtrate  treated  as  above.  In  the  solutions 
so  obtained  oxalic  acid  is  characterized  by  the  tests  given  above. 


288  MANUAL    OF    CHEMISTRY 

The  urine  is  also  to  be  examined  microscopically  for  crystals  of  cal- 
cium oxalate.  The  stomach  may  contain  small  quantities  of  oxalates 
as  normal  constituents  of  certain  foods. 

/POOTT 

Malonic  Acid — ^H2<^CQOH —  *S  a  Pro<^uc^  °^  ^e  oxidation  of 
malic  acid  (p.  295),  or  of  normal  propyl  glycol.  It  is  best  obtained 
by  the  general  method  4,  p.  285.  Monochloracetic  acid  is  converted 
into  cyano- acetic  acid  by  heating  in  alkaline  solution  with  KCN: 
CH2C1.COOH+KCN  =  CN.CH2.COOH  +  KC1.  The  cyano-acid  is 
then  hydrolysed  by  heating  with  KHO  or  HC1,  thus:  CN.CH2.- 
COOH+2H2O  =  COOH.CH2.COOH  +  NH3.  It  forms  large  pris- 
matic crystals,  soluble  in  water,  alcohol  and  ether;  fusible  at  132° 
(269.6°  F.),  and  decomposed  at  about  150°  (302°  F.)  into  acetic 
acid  and  carbon  dioxid. 

CH2— COOH 

Succinic  Acid —  |  — 118  —  exists  in  amber,  coal,  fossil 

CH2— COOH 

wood,  and  in  small  quantity  in  animal  and  vegetable  tissues.  Its 
presence  has  been  detected  in  the  normal  urine  after  the  use  of  fruits 
and  of  asparagus,  in  the  parenchymatous  fluids  of  the  spleen,  thyroid, 
and  thymus,  and  in  the  fluids  of  hydrocele  and  of  hydatid  cysts.  It 
is  also  formed  in  small  quantity  during  alcoholic  fermentation;  as  a 
product  of  oxidation  of  many  fats  and  fatty  acids;  and  by  synthesis 
fromethylenecyanid:CN.(CH2)2.CNH-4H20=-COOH.(CH2)2.COOH+ 
2NHa.  It  may  also  be  obtained  by  dry  distillation  of  amber,  or  by  the 
fermentation  of  malic  acid  (p.  295). 

It  crystallizes  in  large  prisms  or  hexagonal  plates,  which  are  color- 
less, odorless,  permanent  in  air,  acid  in  taste,  soluble  in  water,  spar- 
ingly so  in  ether  and  in  cold  alcohol.  It  fuses  at  180°  (356°  F.),  and 
distils  with  partial  decomposition  at  235°  (455°  F.).  It  withstands 
the  action  of  oxidizing  agents.  Reducing  agents  convert  it  into  the 
corresponding  acid  of  the  fatty  series,  butyric  acid.  With  Br  it  forms 
products  of  substitution.  H2SO4  is  without  action  upon  it.  Phos- 
phoric anhydrid  removes  H2O  and  converts  it  into  succinic  an- 
hydrid,  C^Os. 

/POOTT 

Isosuccinic  Acid  —  Methyl -malonic  acid  —  CHa  .CH<^COOH  —  is 
formed  by  the  action  of  hydrating  agents  upon  «  cyanopropionic  acid. 
It  forms  prismatic  crystals,  fusible  at  130°  (266°  F.),  and  is  decom- 
posed at  higher  temperatures  into  propionic  acid  and  carbon  dioxid. 

Glutaric  Acid— COOH.  (CH2)  3. COOK— Normal  Pyrotartaric  acid 
— the  next  superior  homologue  of  succinic  acid,  is  formed  by  reduc- 
tion of  <*  oxyglutaric  acid  (p.  295).  It  crystallizes  in  large  plates, 
very  soluble  in  water,  which  fuse  at  27°  (206.4  °F.).  The  corre- 
sponding amido-acid  is  one  of  the  products  of  decomposition  of  pro- 
tein bodies. 


ALCOHOL- ACIDS  —  OXYACIDS  289 

The  pyrotartaric  acid  obtained  by  the  action  of  heat  on  tartaric 
acid  is  methyl-succinic  acid,  COOH.CH(CH3).CH2.COOH,  which 
may  also  be  produced  synthetically  by  the  action  of  nascent  H  upon 
itaconic  acid,  COOH.C(  :CH2).CH2.COOH,  as  well  as  by  other 
methods.  It  fuses  at  112°  (233.6°  F.),  and  forms  rhombic  prisms, 
very  soluble  in  water,  alcohol,  and  ether. 

Adipic  Acid— COOH.(CH2)4.COOH— is  a  product  of  the  action 
of  nitric  acid  on  fats:  Pimelic  acid,  COOH.(CH2)5.COOH,  and 
Suberic  acid,  COOH.(CH2)6.COOH— are  similarly  obtained  from 
cork.  Azelaic  acid,  CgHieO^t,  Sebacic  acid,  CioHisC^,  Brassylic  acid, 
CnH2oO4,  and  Rocellic  acid,  Ci7H32O4,  also  belong  to  this  series. 


PARAFFIN    TRI-,    TETRA-,    AND    PENTA - C ARBOXYLIC    ACIDS. 

Tricarboxylic  Acids  in  which  more  than  one  carboxyl  are  at- 
tached to  the  same  carbon  atom  exist  only  in  their  esters.  The 
simplest  of  these:  Methenyl  tricarboxylic  ester,  CH(COO.C2H5)3,  is 
a  crystalline  solid,  fusing  at  29°  (84.2°  F.),  and  boiling  at  253° 
(487.4°  F.). 

Tricarballylic  Acid— CH2. (COOH) .CH(COOH) .CH2(COOH)— in 
which  the  carboxyls  are  attached  to  different  carbon  atoms,  is  a  more 
stable  compound.  It  exists  in  unripe  beets  and  in  the  vacuum  pan 
residues  of  beet -sugar  works.  It  is  formed  by  a  variety  of  reactions, 
as  by  heating  tribromhydrin  with  potassium  cyanid  and  decomposing 
the 'cyanid  with  potash:  CH2Br.CHBr.CH2Br+3KCN— CH2CN.- 
CHCN.CH2CN  +  3KBr,  and  CH2CN.CHCN.CH2CN  +  6H2O  =  CH2- 
COOH.CH.COOH.CH2COOH  +  3NH3.  It  forms  rhombic  prisms 
soluble  in  water,  fusible  at  164°  (327.2°  F.). 

Camphoronic  Acid — aa/2  trim  ethyl -tricarballylic  acid — (CH3)2C- 
(COOH).(CH3)C(COOH).CH2(COOH)— is  a  product  of  oxidation  of 
camphor  (q.  v.). 

Dimalonic  Acid— coOH/CH-CH\COOH— the  simplest  of  the 
tetracarboxylic  acids,  is  a  crystalline  solid,  fusible  at  168°  (334.4° 
F.).  On  further  heating  it  yields  ethylene  succinic  acid:  (COOH)2- 
CH.CH(COOH)2=COOH.CH2.CH2.COOH+2CO2. 

Propenyl-pentacarboxylic  acid — C3H3(COOH)5 — is  also  known. 


ALCOHOL-ACIDS— OXYACIDS. 

These   acids   contain,   besides   the   carboxyl   group,    one   of    the 

groups  CH2OH,  CHOH,  or  COH,  which  characterize  the  primary, 

secondary,  and  tertiary  alcohols.     They,  therefore,  have  the  function 

of  alcohols,  primary,  secondary,  or  tertiary,  as  well  as  that  of  acids: 

19 


CH3 

(CH3)2 

CHOH 

II 

COH 

I 

1 

COOH 

COOH 

o  Oxypropionic  acid 

a  Oxyisobutyric  acid 

(secondary). 

(tertiary). 

290  MANUAL    OF    CHEMISTRY 


CH2OH 
OOOH 


Glycollic  acid 
(primary). 

They  may  be  considered  as  derived  either  from  the  di-  and  polya- 
tomic alcohols  (glycols,  glycerols,  etc.)  by  incomplete  oxidation,  as 
COOH.CH2OH  from  CH2OH.CH2OH;  or  from  the  pure  acids  by  sub- 
stitution of  OH  for  H  atoms  in  the  remaining  hydrocarbon  groups, 
as  CH2OH.CH2.CH2.COOH  ;  CH2OH.CHOH.CH2.COOH,  and  CH2- 
OH.CHOH.CHOH.COOH  from  CH3.CH2.CH2.COOH. 

The  basicity  of  these  acids  is  represented  by  the  number  of  car- 
boxyl  groups  which  they  contain,  their  atomicity  by  the  number  of 
hydroxyls.  Thus  CH2OH.CHOH.COOH  is  monobasic  and  triatomic. 

The  algebraic  formulae  of  the  several  monobasic  series  are  C«H2«O3 ; 
C«H2»O4,C«H2wO5,  etc.,  those  of  the  dibasic  series  CWH2«_2O5,C«H2«_2O6, 
etc.;  and  those  of  the  tribasic  series  C«H2«_4O7,C«H2«-4O8,  etc. 

OXYACETIC    SERIES.       C«H2«O3. 

The  acids  of  this  series  contain  one  carboxyl  and  one  alcoholic 
group.  They  are,  therefore,  monobasic  and  diatomic,  and  may  be 
considered  as  derived  from  the  glycols  by  oxidation  of  one  CH2OH 
group,  or  from  the  acids  of  the  acetic  series  by  substitution  of  OH  for 
H  in  a  hydrocarbon  group  (oxyacetic). 

They  are  formed:  (1)  By  the  limited  oxidation  of  the  correspond- 
ing glycols  or  oxyaldehydes :  CH2OH.CH2OH+O2=  CH2OH.COOH+ 
H2O,  or,  2CH2OH.CHO+O2==2CH2OH.COOH;  (2)  By  the  action  of 
nascent  hydrogen  upon  the  aldehyde  or  ketone  acids  (p.  297),  or  upon 
the  acids  of  the  oxalic  series:  CHO.COOH+H2==CH2OH.COOH,  or, 
CH3.CO.COOH+H2=CH3.CHOH.COOH,  or,  COOH.COOH+2H2= 
CH2OH.COOH+H2O  ;  (3)  By  heating  the  monohalogen  fatty  acids 
with  silver  or  potassium  hydroxids,  or  with  water:  CH2C1.COOH+ 
KHO=CH2OH.COOH  +  KC1,  or,  CH2C1.COOH+H2O=HC1 +CH2- 
OH.COOH;  (4)  From  the  aldehydes  and  ketones,  by  their  conver- 
sion, first  into  oxycyanids  by  the  action  of  hydrocyanic  acid:  CH3.- 

CHO+HCN=CH3.CH<(cN,  and  the  action  uP°n  these  of  acids  or 
alkalies:  CH3.CH<^cN+2H2O=CH3.CHOH.COOH+NH3. 

Isomeres — Position  or  Place  Isomery. — Considering  the  oxy- 
butyric  acids  as  derived  from  normal  and  isobutyric  acids  by  substi- 
tution of  one  OH  for  a  hydrogen  atom  in  a  hydrocarbon  group,  the 
following  five  derivatives  are  possible  : 


ALCOHOL-  ACIDS  —  OXYACIDS 


291 


CH3 
CH2 
CH2 
COOH 


I. 
CH3 

CH2 

CHOH 
I 


III. 
CH2OH 


II. 
CH3 

I  I 

CHOH    CH2 

CH2        CH2 

I 


rv. 

V. 

H3C    CH3 

H3C    CH2OH 

H3C    CH3 

\/ 

\/ 

\/ 

CH 

CH 

COH 

COOH 

COOH 

COOH 

COOH  COOH  COOH 

Alpha        Beta  Gamma 
Normal        Oxy-           Oxy-          Oxy 

Butyric     butyric  butyric  butyric 
acid.          acid.         acid.          acid. 


Isobutyric 
acid. 


Beta 

Oxyisobutyric 
acid. 


Alpha 

Oxyisobutyric 
acid. 


While  III,  IV,  and  V  are  obviously  different  in  molecular  struc- 
ture from  each  other  and  from  I  and  II,  in  that  the  latter  contain  the 
group  CHOH,  while  the  former  contain  the  groups  CH20H,CH,  and 
COH,  the  only  difference  between  I  and  II,  whose  molecules  are  com- 
posed of  identical  groups,  is  in  the  position  or  place  of  the  alcoholic 
hydroxyl  with  reference  to  the  carboxyl  group.  Place  isomeres  of 
this  kind  are  distinguished  by  designating  that  in  which  the  second 
substituted  group  (in  this  case  the  OH)  is  attached  to  the  carbon 
atom  contiguous  to  the  first  as  the  alpha,  or  1- compound,  and  the 
others  by  the  succeeding  Greek  letters,  or  by  the  numerals  in  the 
order  of  the  removal  of  the  position  of  the  second  substitution.  Thus 
II  above  is  Beta  oxybutyric  or  2 -oxy butyric  acid.  (See  Orientation, 
p.  381.) 

The  «,  /?,  y,  and  8  acids  differ  in  their  products  of  dehydration: 
The  «  acids  yields  cyclic  double  esters,  called  lactids,  by  elimination 
of  H2O  from  two  molecules  of  the  acid  (p  320).  The  ft  acids  are 
converted  into  unsaturated  acids  by  loss  of  H2O  from  one  molecule  of 
the  acid:  CH2OH.CH2.COOH  =  CH2:CH.COOH+H2O.  The  y  and  8 
acids,  and  those  of  greater  carbon  content,  are  converted  into  simple 
cyclic  esters,  called  lactones,  by  elimination  of  H2O  from  a  single 
molecule  of  the  acid  (p.  320). 

By  further  oxidation  the  primary  oxyacids  containing  CH2OH 
yield  aldehyde  acids:  2CH2OH.COOH+O2  =  2CHO.COOH+2H2O, 
and  then  dibasic  acids:  2CHO.COOH+O2  =  2COOH.COOH;  the  sec- 
ondary acids,  containing  CHOH,  yield  ketoue  acids:  2CHs.CHOH.- 
COOH+O2=2CH3.CO.COOH+2H20,  and  the  tertiary  acids,  con- 

/"^TT     \ 

taining  COH,  yield  ketones,  carbon  dioxid  and  water  :  2CH^COH.- 
COOH+O2=2CH3.CO.CH3H-2CO2+2H2O. 

The  hydrogen  of  their  carboxyl  group  may  be  replaced  to  form 
salts,  esters,  or  amids  ;  and  the  hydroxyl  of  their  alcoholic  group 
may  be  replaced  by  alkali  metals,  alkyls,  or  acidyls.  In  other  words, 
they  behave  as  acids  and  as  alcohols. 

Oxyformic  Acid— Carbonic  acid—  OC( OH) 2.—  Although  this  acid 
does  not  exist  free,  but  is  decomposed  as  soon  as  liberated  into  CO2 
and  H20  (p.  225),  its  salts,  the  carbonates,  are  well  known  and  quite 


292  MANUAL    OF    CHEMISTRY 

stable.  The  position  of  this  acid  in  this  series  is  an  apparent 
anomaly,  as  it  is  dibasic,  not  monobasic  like  the  other  terms  of  the 
series.  But  if  we  bear  in  mind  that  the  basic  nature  of  the  H  atom 
in  a  hydroxyl  depends  upon  its  close  union  with  a  CO  group  (or  some 
other  electro  negative  group),  it  is  evident  that  the  two  H  atoms  in 
the  inferior  homologue  of  glycollic  acid,  being  similarly  united  to  the 
same  CO  group,  must  be  equally  basic  : 

CH2OH  /OH 

—    CH2    =    OC 
COOH  \OH 

Glycollic  acid,  Carbonic  acid. 

Indeed,  carbonic  acid  is  not  an  alcohol  acid,  but  a  pure  acid,  as  it 
contains  no  alcoholic  group. 

Esters  are  also  known  corresponding  to  orthocarbonic  acid : 
C(OH)4,  although  the  acid  itself  is  unknown. 

Glycollic  Acid— Oxyacetic  acid— CH2OH. COOH— is  formed  by 
the  oxidation  of  glycol,  by  the  action  of  nitrous  acid  upon  glycocoll, 
and  by  the  action  of  KHO  upon  monochloracetic  acid,  or  upon 
glyoxal,  CHO.CHO. 

It  forms  deliquescent  acicular  crystals,  very  soluble  in  water,  alco- 
hol and  ether.  It  fuses  at  80°  (176°  F.) .  It  is  oxidized  by  HNO3  to 
oxalic  acid. 

Lactic  Acids — Oxypropionic  acids — Alpha  oxypropionic  acid — 
Ethidene  lactic  acid — CH3.CHOH.COOH— is  formed  from  milk  sugar, 
cane  sugar,  gum  and  starch  by  lactic  fermentation,  induced  by  the 
lactic  acid  bacillus.  It  consequently  exists  in  many  soured  products, 
such  as  soured  milk,  sour-krout,  fermented  beet-juice,  and  the  waste 
liquors  of  starch  works  and  of  tanneries.  It  is  formed  in  the  stomach 
during  digestion  of  carbohydrates.  It  is  prepared  by  allowing  a  mix- 
ture of  cane  sugar,  tartaric  acid,  rotten  cheese,  skim  milk  and  chalk 
to  ferment  for  ten  days  at  35°  (95°  F.).  It  has  also  been  obtained 
by  oxidation  of  alpha  propylene  glycol  :  CH3.CHOH.CH2OH+O2= 
CH3.CHOH.COOH-fH2O. 

Lactic  acid  of  fermentation  is  a  colorless,  or  yellowish,  syrupy 
liquid;  sp.  gr.  1.215  at  20°  (68°  F.);  soluble  in  water,  alcohol  and 
ether.  It  does  not  distil  without  decomposition,  but  when  heated  it 
yields  lactid  (p.  320),  carbon  monoxid,  aldehyde  and  water.  Oxid- 
izing agents  convert  it  into  pyroracemic  acid:  CH3.CO.COOH;  or, 
if  more  energetic,  split  it  up  into  acetic  acid  and  carbon  dioxid: 
CH3.CHOH.COOH+O2=CH3.COOH+C02+H2O.  Heated  to  130° 
(266°  F.)  with  dilute  sulfuric  acid  it  splits  into  aldehyde  and  formic 
acid:  CH3.CHOH. COOH  =  CH3.CHO+H. COOH.  Hydriodic  acid 
reduces  it  to  propionic  acid;  but  hydrobromic  acid  converts  it  into 
a-bromopropionic  acid. 


ALCOHOL- ACIDS  —  OXYACIDS  293 

Ethidene  lactic  acid  contains  an  asymmetric  carbon  atom  (p.  267) : 
CH3.*CHOH.COOH;  and  that  produced  by  lactic  fermentation  is 
optically  inactive  (d+1).  The  dextro  acid,  also  known  as  sarcolactic 
or  paralactic  acid,  is  best  obtained  from  Liebig's  meat  extract;  and 
is  also  produced  by  allowing  Penicillium  glaucum  to  grow  in  a  solu- 
tion of  inactive  ammonium  lactate.  It  exists  in  muscular  tissue  after 
death  and  during  contraction,  and  in  the  spleen,  lymphatic  glands, 
thymus,  thyroid,  blood,  bile,  transudates,  in  the  perspiration  in  puer- 
peral fever,  and  in  the  urine  after  violent  exercise,  in  yellow  atrophy 
of  the  liver  and  in  phosphorus  poisoning,  either  free  or  in  com- 
bination. The  acid  in  muscular  tissue  probably  originates  from 
glycogen . 

Laevolactic  Acid  is  formed  by  the  growth  of  Bacillus  acidi  lae- 
volactici  in  a  solution  of  cane  sugar. 

Ethylene  Lactic  Acid — Beta  oxypropionic  acid  —  Hydracrylic 
acid— CH2OH.CH2.COOH— the  third  form  of  lactic  acid,  is  formed 
by  the  action  of  moist  silver  oxid  upon  /3-iodo-  or  /3-chloropropionic 
acid;  by  the  saponification  of  ethylene  cyanhydrin;  or  by  the  oxida- 
tion of  the  corresponding  glycol.  It  is  a  thick,  uncrystallizable 
syrup,  which  is  converted  by  dehydration  into  acrylic  acid  CH2OH.- 
CH2.COOH=CH2:CH.COOH+H2O.  On  oxidation  it  yields  oxalic 
acid  and  carbon  dioxid:  2(CH2OH.CH2.COOH)  +  5O2  =  2(COOH.- 
COOH)+2CO2+4H2O. 

Oxybutyric  Acids. — Five  isomeres  are  possible  (p.  291).  Beta 
oxybutyric  acid— CH3.*CHOH.CH2.COOH,  is  formed  by  the  action 
of  sodium  amalgam  upon  acetoacetic  ester  (p.  313)  CH3.CO.CH2.- 
COOH+H2  =  CH3.CHOH.CH2.COOH.  The  lavo-acid,  a  colorless 
syrup,  readily  soluble  in  water,  alcohol  and  ether,  occurs,  accom- 
panied by  acetoacetic  acid,  in  the  blood  and  urine  in  severe  cases  of 
diabetes. 

Alpha  Oxycaproic  Acid— CH3.(CH2)3.CHOH.COOH— is  leucic 
acid,  obtained  by  oxidizing  leucin  (p.  365)  by  nitrous  acid. 

HIGHER  MONOCARBOXYLIC  OXYACIDS. 

Representatives  of  the  following  series  are  known : 
Dioxymonocarboxylic  Series,  Glyceric  Series — C»H2»O4. — The 
acids  of  this  series  bear  the  same  relation  to  the  glycerols  that  those 
of  the  oxyacetic  series  bear  to  the  glycols.  Glyceric  acid,  CH2OH.- 
*CHOH.COOH,  is  an  uncrystallizable  syrup  obtained  by  the  limited 
oxidation  of  glycerol. 

Trioxymonocarboxylic  Series — C»H2»O5 — of  which  erythritic,  or 
erythroglucic  acid:  CH2OH.  (CHOH)2.COOH,  derived  from  erythrol 
(p.  254)  is  the  first  term. 


294  MANUAL    OF    CHEMISTRY 

Tetroxymonocarboxylic  Series — C*H2«O6 — are  obtained  by  oxida- 
tion of  the  aidopentoses  (p.  264). 

Pentoxymonocarboxylic  Series — C«H2«O7 — are  obtained  by  oxi- 
dation of  the  hexahydric  alcohols  and  aldohexoses.  Synthetically, 
they  are  produced  from  the  aidopentoses.  by  their  conversion  into 
nitrils  of  the  oxyacids  by  CNH,  and  the  action  upon  these  of  HC1, 
thus  1-arabinose  CH2OH.(CHOH)3.CHO  yields  1-glucononitril,  CH2- 
OH.(CHOH)3.CH(OH)CN,  and  this  yields  1-gluconic  acid,  CH2OH.- 
(CHOH)4.COOH. 

These  acids  are  very  unstable  when  free,  easily  losing  water  to 
form  lactones  (p.  320).  They  readily  unite  with  phenylhydrazin  to 
form  phenylhydrazids,  such  as  gluconophenyl  hydrazid:  CH2OH.(CH- 
OH^.CO.NH.NH.CeHs,  which  crystallize  in  characteristic  forms  (pp. 
264,  430).  They  form  numerous  space  isomeres.  Their  lactones 
treated  with  sodium  amalgam,  take  up  H2  and  produce  the  corre- 
sponding aldohexoses:  thus  gluconolactone  yields  glucose. 

Mannonic  Acids— C5H6(OH)5.COOH.— The  three  acids,  d-,  1-, 
and  (d+1),  derived  from  the  corresponding  mannitols,  yield  the  cor- 
responding dibasic  mannosaccharic  acids  on  oxidation.  They  are 
syrupy  liquids,  which  are  converted  into  their  lactones  by  evaporation 
of  their  solutions.  On  heating  d-  and  1-mannonic  acids  with  quin- 
olin  to  140°  (284°  F.),  they  are,  in  part,  converted  into  d-  and  1- 
gluconic  acids.  By  this  action  and  the  subsequent  conversion  of 
gluconolactone,  referred  to  above,  glucose  may  be  synthetically  ob- 
tained from  mannitol. 

Gluconic  Acids  — CH2OH.(CHOH)4.COOH.— The  d-,  1-,  and 
(d+1)  acids  are  known.  By  oxidation  they  yield  the  corresponding 
saccharic  acids.  The  lactones  yield  d-,  1-,  and  (d+1)  glucose  by 
reduction,  d- Gluconic  acid,  also  known  as  dextronic  or  maltonic 
acid,  is  a  syrup  which  forms  a  crystalline  lactone  on  evaporation  of 
its  solution.  It  is  formed  by  oxidizing  dextrose,  dextrin,  starch,  cane 
sugar,  or  maltose  by  chlorin  or  bromin  water. 

Acids  belonging  to  the  still  higher  series  C«H2nO8,C«H2»O9,  and 
C«H2»Oio,  corresponding  to  the  heptoses,  octoses  and  nonoses  (p.  264) 
are  also  known. 

MONOXYDICAEBOXYLIC    SERIES — C«H2«-2O5. 

The  acids  of  this  series  contain  two  carboxyls  and  one  alcoholic 
group.  They  are,  therefore,  dibasic  and  triatomic,  and  may  be  con- 
sidered as  derived  from  the  glycerols  by  oxidation  of  both  CH2OH 
groups.  They  may  also  be  considered  as  derived  from  the  paraffin 
dicarboxylic  acids  (oxalic  series),  above  the  first,  by  substitution  of 
OH  for  H  in  a  hydrocarbon  group,  in  the  same  manner  as  the  acids 


ALCOHOL- ACIDS  —  OXYACIDS  295 

of  the  oxyacetic  series  are  derived  from  those  of  the  acetic  series 
(p.  290). 

Tartronic  Acid— Oxymalonic  acid~COOH.CHOH.COOH— is 
formed  by  the  action  of  moist  silver  oxid  upon  monochloro-  or 
monobromo-malonic  acid,  or  by  oxidation  of  glycerol  by  potassium 
permanganate.  It  crystallizes  in  large  prisms,  readily  soluble  in 
water,  alcohol,  and  ether,  and  fusible  at  184°  (363.2°  F.). 

Malic  Acid  —  Oxysuccinic  acid—  COOH.CH2.*CHOH.COOH— 
exists  in  three  modifications.  The  lasvo-acid  exists  free,  and  in  com- 
bination with  K,  Na,  Ca,  Mg,  and  organic  bases  in  apples,  pears, 
and  similar  fruits,  and  in  the  berries  of  the  mountain  ash  and  in 
gooseberries.  The  inactive  (d+1),  acid  may  be  obtained  from  mono- 
bromo-succinic  acid  by  the  action  either  of  moist  silver  oxid,  of  dilute 
HC1,  of  dilute  NaHO,  or  even  of  boiling  water;  and  by  several  other 
methods.  The  dextro-acid  is  obtained  by  the  reduction  of  dextro- 
tartaric  acid  by  hydriodic  acid. 

The  natural  malic  acid  crystallizes  in  prismatic  needles;  odorless; 
acid  in  taste;  fusible  at  100°  (212°  F.);  deliquescent;  very  soluble 
in  water  and  in  alcohol.  Heated  to  140°  (284°  F.)  it  loses  water 

with  formation  of  fumaric  acid,  COOH.CH:CH.COOH.  At  180° 

CH.CO\ 

(356°  F.)  it  yields  water,  fumaric  acid  and  male'ic  anhydrid,  II  O. 

CH.CO/ 

Reducing  agents  convert  it  into  succinic  acid.     The  malates  are  oxi- 
dized to  carbonates  in  the  body. 

Oxyglutaric  Acid  exists  in  the  two  isomeres :  «  oxyglutaric  acid, 
COOH.CH(OH).CH2.CH2.COOH,  which  occurs  in  molasses,  crystal- 
lizes with  difficulty,  and  fuses  at  72°  (161.6°  F.);  and  ft  oxyglutaric 
acid,  COOH.CH2.CHOH.CH2.COOH,  which  fuses  at  95°  (203°  F.). 


DIOX  YDIC  ARBOXYLIC  ACIDS — C«H2«_2Oe . 

Tartaric  Acids — Dioxyethylene  Succinic  Acids. — There  exist 
four  acids  having  the  composition  C^eOe,  which  are  readily  convert- 
ible one  into  the  other.  They  are:  Dextro- tartaric,  or  ordinary  tar- 
taric  acid ;  Icevo-tartaric  acid\  mesotartaric,  or  antitartaric  acid-,  and 
racemic,  or  paratartaric  acid.  The  first  three  of  these  are  stereoiso- 
meres,  due  to  the  presence  of  two  asymmetric  carbon  atoms  in  the 
molecule,  whose  molecular  structure  has  been  discussed  under  the 
head  of  space  isomery  (p.  267).  Mesotartaric  acid,  which  is  opti- 
cally inactive,  has  a  molecular  structure  differing  from  those  of  the  d- 
and  1-  acids,  into  which  it  cannot  be  split.  Racemic  acid,  also  opti- 
cally inactive,  is  the  (d+1)  acid,  and  can  be  readily  decomposed  into 
them  or  separated  from  a  mixture  of  them. 

Dextro-tartaric  Acid — Ordinary  tartaric  acid — Acidum  tartaricum 


296  MANUAL    OF    CHEMISTRY 

(U.  S.;  Br.) — occurs,  both  free  and  in  combination,  in  the  sap  of  the 
vine  and  in  many  other  vegetable  juices  and  fruits,  particularly  in 
grape -juice.  Although  this  is  probably  the  only  tartaric  acid  existing 
in  nature,  all  four  varieties  may  occur  in  the  commercial  acid,  being 
formed  during  the  process  of  manufacture.  Tartaric  acid  is  obtained 
in  the  arts  from  hydropotassic  tartrate,  or  cream  of  tartar  (p.  179). 

The  ordinary  tartaric  acid  crystallizes  in  large  prisms;  very  sol- 
uble in  H2O  and  in  alcohol;  acid  in  taste  and  reaction.  Heated  with 
water  at  165°-175°  (329°-347°  F.)  it  is  converted  into  mesotartaric 
and  racemic  acids.  It  fuses  at  170°  (338°  F.) ;  at  180°  (356°  F.)  it 
loses  EbO,  and  is  gradually  converted  into  an  anhydrid;  at  200°-210° 
(392°-410°  F.)  it  is  decomposed  with  formation  of  pyruvic  acid, 
C3H403  (p.  298),  and  pyrotartaric  acid,  C5H8O4,  (p.  289);  at  higher 
temperatures  CO2,  CO,  H2O,  hydrocarbons  and  charcoal  are  produced. 

Tartaric  acid  is  attacked  by  oxidizing  agents  with  formation  of 
CO2,  EbO,  and,  in  some  instances,  formic  and  oxalic  acids.  Certain 
reducing  agents  convert  it  into  malic  and  succinic  acids.  With  fum- 
ing HNOs  it  forms  a  dinitro- compound,  which  is  very  unstable,  and 
which,  when  decomposed  below  36°  (96.8°  F.),  yields  tartaric  acid. 
It  forms  a  precipitate  with  lime-water,  soluble  in  an  excess  of  H2O. 
In  not  too  dilute  solution  it  forms  a  precipitate  with  potassium  sulfate 
solution.  It  does  not  precipitate  with  the  salts  of  Ca.  When  heated 
with  a  solution  of  auric  chlorid  it  precipitates  the  gold  in  the  metallic 
form. 

When  taken  into  the  economy,  as  it  frequently  is  in  the  form  of 
tartrates,  the  greater  part  is  oxidized  to  carbonic  acid  (carbonates) ; 
but,  if  taken  in  sufficient  quantity,  a  portion  is  excreted  unchanged 
in  the  urine  and  perspiration.  The  free  acid  is  poisonous  in  large 
doses.  The  acids  and  its  salts  are  largely  used  in  pharmacy  and  in 
dyeing. 

Lcevo-tartaric  —  forms  crystals  similar  to  those  of  the  dextro  acid, 
but  having  opposite  hemihedral  facets  (p.  11),  so  that  the  crystals  of 
one  acid  resemble  the  reflection  of  those  of  the  other  in  a  mirror. 

Racemic  Acid — (d-\-l)  Tartaric  acid — is  produced  when  concen- 
trated solutions  of  equal  quantities  of  d-  and  1- tartaric  acids  are 
mixed.  It  is  formed  by  oxidation  of  dulcitol  and  of  mannitol.  It  is 
obtained  by  the  action  of  moist  silver  oxid  upon  dibromo  succinic 
acid:COOH.CHBr.CHBr.COOH+2AgHO  =  COOH.CHOH.CHOH.- 
COOH+2AgBr;  and  by  several  other  synthetic  methods.  It  crys- 
tallizes in  rhombic  prisms,  less  soluble  in  water  than  ordinary  tartaric 
acid,  and  fuses  at  205°  (410° F.). 

Mesotartaric  Acid — Inactive  Tartaric  acid — is  obtained  by  oxida- 
tion of  erythrol;  or  by  heating  dextrotartaric  acid  with  water  at  165° 
(329°  F.)  for  two  days. 


ALDEHYDE- ACIDS  297 


HIGHER    DICARBOXYLIC     OXYACIDS. 

The  carbohydrates,  on  oxidation  with  nitric  acid,  yield  tetroxy- 
dicarboxylic  acids:  COOH.(CHOH)4.COOH.  Among  these  are: 
mannosaccharic  acids,  derived  from  the  mannonic  acids  (p.  294); 
saccharic  acids ;  and  mucic  acid.  Of  the  three  saccharic  acids  the 
d-acid  is  the  best  known.  It  is  produced  by  oxidation  of  many  car- 
bohydrates, including  cane  sugar  and  grape  sugar,  by  nitric  acid,  and 
by  the  action  of  bromin  water  on  glucuronic  acid  (p.  299).  Nascent 
H  reduces  it  to  glucuronic  acid.  It  forms  a  syrup  or  a  deliquescent 
solid,  which,  on  standing,  changes  to  a  crystalline  lactone.  Mucic 
acid  is  produced  by  the  oxidation  of  dulcitol,  milk  sugar,  and  the 
gums.  It  is  a  white  solid,  almost  insoluble  in  cold  water  and  in 
alcohol,  which  fuses  at  210°  (410°  F.).  When  heated  it  loses  CO2 
and  forms  pyromucic,  or  furfurane  monocarboxylic  acid  (p.  455). 

Pentoxydicarboxylic  acids  are  also  known,  of  which  the  type  is 
pentoxypimelic  acid:  COOH.(CHOH)5.COOH. 

OXYTRICARBOXYLIC    ACIDS— C*H2«-4O7. 
/CH2.COOH 

Citric  Acid — HO.C— COOH  exists  in  the  juices  of  many  fruits, 

\CH2.COOH 

lemon,  strawberry,  currant,  and  in  small  quantity,  as  calcium  citrate, 
in  cow's  milk.  It  is  obtained  commercially  from  lemon  juice.  It 
crystallizes  in  large,  rhombic  prisms,  very  soluble  in  water  and  in 
alcohol.  It  fuses  at  100°  (212°  F.);  at  175°  (347°  F.)  it  is  decom- 
posed with  loss  of  water  and  formation  of  aconitic  acid  (p.  376) ;  and 
at  a  higher  temperature  CO2  is  given  off  and  citraconic  and  itaconic 
acids  are  produced.  In  the  body  its  salts  are  oxidized  to  carbonates. 


ALDEHYDE- ACIDS. 

These  are  substances  having  both  aldehyde  and  acid  functions, 
and  containing  the  groups  CHO  and  COOH.  The  simplest  of  the 
class  is  formic  acid,  already  referred  to  as  the  first  term  of  the  acetic 
series  (p.  278),  in  which,  however,  the  carbon  atom  is  common  to  the 

two  groups  :    0:C\oH. 

Glyoxylic  Acid — CHO. COOH — when  produced  unites  with  water 
to  form  a  hydrate:  (OHhrCH.COOH,  corresponding  to  chloral  hy- 
drate (p.  259)  :(OH)2:CH.CC13.  This  is  a  thick  syrup,  or  it  forms 
rhombic  prisms.  It  is  produced  by  heating  dichloracetic  acid  with 
water  at  230°  (446°  F.)  :  CHCl2.COOH+H2O=CHO.COOH-h2HCl. 
It  has  the  reducing  power  and  other  properties  of  the  aldehydes. 


298  MANUAL    OF    CHEMISTRY 

KETONE-  ACIDS. 

These  compounds  contain  both  the  ketonic  and  carboxyl  groups, 
CO  and  COOH. 

The  monoketone  -  monocarboxylic  acids  contain  one  CO  and  one 
COOH.  According  as  the  CO  group  occupies  the  position  adjacent 
to  the  carboxyl,  or  further  removed  therefrom,  these  acids  are  desig- 
nated as  a,  j8f  y,  etc.;  thus  CH3.CH2.CO.COOH=a,  CH3.CO.CH2.- 
COOH=/2,  etc. 

The  a,  y,  8?  etc.,  acids  are  much  more  stable  than  the  /3-acids,  and 
may  be  obtained  by  oxidation  of  the  corresponding  secondary  alcohol 
acids.  The  <*  acids  are  derivable  from  formic  acid  by  substitution  of 
acidyls  for  the  extra  -carboxylic  hydrogen:  (CH3.CO).COOH. 

Pyruvic  Acid  —  Pyroracemic  acid  —  CH3.CO.COOH  —  is  formed  by 
oxidation  of  a-oxypropionic  acid  :  2CH3.CHOH.COOH+O2=2CH3.- 
CO.COOH+2H2O.  It  is  also  formed  by  distillation  of  tartaric  acid  : 
COOH.CHOH.CHOH.COOH=CH3.CO.COOH+C02+H2O. 

The  /?-  ketone  acids  are  more  unstable,  and  are  decomposed  by 
heat  with  formation  of  ketone  and  carbon  dioxid:  COOH.CH2.CO.- 
CH3=CO2+CH3.CO.CH3.  Their  esters  are,  however,  quite  stable, 
and  are  employed  in  many  syntheses.  The  ft  acids  bear  the  same 
relation  to  acetic  acid  that  the  <*  acids  do  to  formic  acid:  (CH3.CO).- 
CH2.COOH. 

Aceto-acetic  Acid—  CH3.  CO.  CH2.  COOH—  may  be  obtained  as  a 
thick,  strongly  acid  liquid  by  saponification  of  its  esters.  Heat  de- 
composes it  into  acetone  and  carbon  dioxid,  according  to  the  equation 
given  above.  Aceto-acetic  acid  accompanies  /3-oxybutyric  acid  and 
acetone  in  the  urine  in  diabetes.  (See  Aceto-acetic  ester,  p.  313). 
Diketone-monocarboxylic  acids,  such  as  CH3.CO.CO.COOH,  are  also 
known,  as  well  as  triketone  monocarboxylic  acids,  and  mono-,  di-, 
and  triketone  dicarboxylic  acids.  Aldehyde-ketone  acids,  such  as 
CHO.CO.COOH,  also  exist. 


TTO\ 

Mesoxalic  Acid  —  Dioxymalonic  acid  —  HO/C\COOH  —  *s  ^ne  mono' 
ketone  -dicarboxylic  acid,  COOH.  CO.  COOH,  combined  with  water  in 
the  same  manner  as  chloral  hydrate  and  glyoxylic  acid  (see  above  and 
pp.  225,  259).  Esters  are  known  corresponding  to  both  forms: 
oxymalonic  esters,  CO:  (COO.C2H5)2,i  and  dioxymalonic  esters, 
C(OH)2:  (COO.C2H5)2.  Mesoxalic  acid  is  obtained  by  the  action  of 
boiling  barium  hydroxid  upon  dibromomalonic  acid  :  COOH.CBr2.- 
COOH-fBa(OH)2=COOH.C(OH)2.COOH-f  BaBr2,  or  upon  alloxan 
(mesoxalylurea).  It  crystallizes  in  prisms,  very  soluble  in  water, 
fusible  at  115°  (239°  F.)  On  evaporation  of  its  aqueous  solution  it 
decomposes  into  carbon  monoxid,  water  and  oxalic  acid;  at  higher 
temperatures  it  yields  carbon  dioxid  and  glyoxylic  acid. 


ACIDS  AND  ETHERS  299 

OXYALDEHYDE  AND  OXYKETONE  ACIDS. 

These  acids  contain  alcoholic  groups,  CH2OH,  CHOH,  or  COH  in 
addition  to  carboxyl  and  either  the  aldehyde  or  ketone  group,  CHO 
or  CO. 

Glucuronic  Acid  — CHO.  (CHOH) 4.COOH  — is  a  derivative  of 
glucose:  CHO.(CHOH)4.CH20H.  It  is  a  syrup  which  passes  into  a 
crystalline  lactone  on  warming.  It  occurs  in  the  urine  in  small  quan- 
tity normally,  in  combination  with  phenol,  skatole  and  indole,  and 
with  camphors,  chloral  and  other  substances  when  these  are  present. 

SIMPLE   ETHERS. 

These  substances  have  been  referred  to  (p.  237)  as  the  simplest 
products  of  oxidation  of  the  hydrocarbons.  The  term  ether  was  for- 
merly applied  to  any  substance  produced  by  the  action  of  an  acid 
upon  an  alcohol.  Such  products  belong,  however,  to  two  distinct 
classes : 

(1)  The  simple  ethers,  or  ethers,  which  are  the  oxids  of  the  hy- 
drocarbon radicals,  and  the  counterparts  of  the  metallic  oxids,  bearing 
the  same  relation  to  the  alcohols  that  the  metallic  oxids  do  to  their 
hydroxids : 

CH3.CH2\0  CH3.CH2\0 

CH3.CH2/°  H/° 

Ethyl  oxid.  Ethyl  hydroxid.  Potassium  Potassium 

(Ether.)  (Alcohol).  oxid.  hydroxid. 

(2)  The   compound   ethers,  now  called  esters,   which  are  the 
products  of  the  reaction  between  an  acid  and  the  alcohol,  the  latter 
behaving  as  a  basic  hydroxid  (p.  239).    They  are  the  counterparts  of 
the  metallic  salts: 

CH3.CH2.0\go  CH3.CH2.0\go              KO\SO  KOX^ 

HO/S°2  CH3.CH2.0/S°2             HO/S°2  KO/S°2 

Monoethylio  Diethylic  Monopotassic              Dipotassic 

sulfate.  sulfate.                               sulfate.                      sulfate 

(Ester-acid.)  (Neutral  ester.)                     (Acid  salt.)  (Neutral  salt.) 

Mixed  ethers  differ  from  simple  ethers  in  that  they  contain  differ- 
ent, in  place  of  similar,  alkyls,  as  methyl-ethyl  oxid:  CH3.O.CH2.- 
CH3 

Simple  and  mixed  ethers  are  formed:  (1)  By  interaction  of  the 
alcohols  and  alkyl-sulfuric  acids.  Thus  methyl -sulf uric  acid  and 
ethylic  alcohol  form  methyl-ethyl  oxid:  S02<^gH3-|-C2H5.0.H  = 
C2H5.O.CH3+S02:  (OH)2.  (2)  By  the  action  of  alkyl  haloids  upon 
sodium  alcoholates:  CH3.Cl+C2H5.O.Na=NaCl-t-C2H5.O.CH3.  (3) 
By  the  action  of  silver  oxid  upon  alkyl  haloids:  2C2HgH-Ag2O= 
2AgI-i-0  (C2H5)2. 


300  MANUAL    OF    CHEMISTRY 

Methyl  oxid — CHa.O.CHs — 46  —  isomeric  with  ethyl  alcohol,  is 
obtained  by  the  action  of  silver  oxid  upon  methyl  iodid,  or  by  the 
action  of  HaSC^  and  boric  acid  upon  methyl  alcohol.  It  is  a  colorless 
gas,  has  an  ethereal  odor,  burns  with  a  pale  flame,  liquefies  at  — 36° 
(—32.8°  F.),  and  boils  at  —21°  (—5.8°  F.),  is  soluble  in  H2O, 
H2SO4  and  ethylic  alcohol. 

Ethyl  Oxid— Ethylic  ether— Sulf uric  ether— ^ther  fortier  (U.  S.) ; 
JEther  purus  (Br.) — C2H5.O.C2Hs. — In  the  manufacture  of  ether  a 
mixture  is  made  of  5  pts.  of  90%  alcohol  and  9  pts.  of  concentrated 
H2SO4,  in  a  vessel  surrounded  by  cold  water,  This  mixture  is  intro- 
duced into  a  retort,  into  which  a  slow  stream  of  alcohol  is  allowed  to 
flow  during  the  remainder  of  the  process.  Heat,  so  regulated  as  not 
to  exceed  140°  (284°  F.),  is  then  applied  to  the  retort,  which  is  con- 
nected with  a  well -cooled  condenser,  and  continued  until  the  tempera- 
ture rises  above  the  point  indicated.  The  distillate  contains  ether, 
alcohol,  water  and  dissolved  gases,  notably  S(>2.  It  is  shaken  with 
water  containing  potash  or  lime,  and  the  ether  decanted  off.  The 
product  is  "washed  ether."  For  further  purification  it  is  treated  with 
calcium  chlorid,  or  recently  burnt  lime,  with  which  it  is  left  in  con- 
tact for  24  hours,  and  from  which  it  is  then  distilled. 

In  the  conversion  of  alcohol  into  ether,  sulfovinic  or  ethyl-sulfuric 
acid  behaves  as  a  "contact  substance"  and  serves  to  carry  an  ethyl 
radical  from  one  alcohol  molecule  to  another,  with  formation  of  water 
and  regeneration  of  sulfuric  acid.  In  the  first  stage  of  the  reaction 
ethyl-sulfuric  acid  is  formed  by  the  action  of  H2S04  upon  alcohol, 
molecule  for  molecule  :  H2SO4+C2H5.OH=H20+C2H5.HSO4.  The 
ethyl-sulfuric  acid  then  reacts  with  another  molecule  of  alcohol, 
according  to  the  general  reaction  (1)  for  the  formation  of  ethers,  to 
form  ether  and  sulfuric  acid:  C2H5.HSO4  +  C2H5.OH  =  H2SO4  + 
(C2Hs)2O.  It  would  seem,  therefore,  that  a  given  quantity  of  H2SO4 
could  convert  an  unlimited  amount  of  alcohol  into  ether.  But  the 
gradual  accumulation  of  the  H2O  formed  in  the  first  stage  of  the 
reaction,  and  the  occurrence  of  secondary  reactions  in  practice  limit 
the  amount  of  ether  produced  to  about  four  or  five  times  the  bulk  of 
acid  used. 

Ether  is  a  colorless  liquid  ;  has  a  sharp,  burning  taste,  and  a  pe- 
culiar, tenacious  odor,  characterized  as  ethereal.  Sp.  gr.  0.723  at 
12.5°  (54.5°  F);  it  boils  at  34.5°  (94.1°  F.).  Its  tension  of  vapor 
is  very  great,  especially  at  high  temperatures;  and  it  is  exceedingly 
volatile.  Water  dissolves  one -ninth  its  weight  of  ether.  Ethylic 
and  methylic  alcohols  are  miscible  with  it  in  all  proportions.  Ether 
is  an  excellent  solvent  of  many  substances  not  soluble  in  water  and 
alcohol.  The  resins  and  fats  are  readily  soluble  in  ether.  The  salts 
of  the  alkaloids  and  many  vegetable  coloring  matters  are  soluble  in 


SIMPLE    ETHERS  301 

alcohol  and  water,  but  insoluble  in  ether,  while  the  free  alkaloids  are 
for  the  most  part  soluble  in  ether,  but  insoluble,  or  very  sparingly 
soluble,  in  water. 

Ether  is  highly  inflammable;  and  burns  with  a  luminous  flame. 
The  vapor  forms  with  air  a  violently  explosive  mixture.  It  is  denser 
than  air,  through  which  it  falls  and  diffuses  itself  to  a  great  dis- 
tance ;  caution  is  therefore  required  in  handling  ether  in  a  locality  in 
which  there  is  a  light  or  fire,  especially  if  the  fire  be  near  the  floor. 

Pure  ether  is  neutral  in  reaction.  H2SO4  mixes  with  it,  with 
elevation  of  temperature,  and  formation  of  sulfovinic  acid.  With  sul- 
furic  anhydrid  it  forms  ethyl  sulfate.  HNO2,  aided  by  heat,  oxidizes  it 
to  carbon  dioxid  and  acetic  and  oxalic  acids.  Ether,  saturated  with 
HC1  and  distilled,  yields  ethyl  chlorid.  Cl,  in  the  presence  of  H2O, 
oxidizes  it,  with  formation  of  aldehyde,  acetic  acid,  and  chloral. 
In  the  absence  of  EbO,  however,  a  series  of  products  of  substitution 
are  produced,  in  which  2,  4,  and  10  atoms  of  H  are  replaced  by  a  cor- 
responding number  of  atoms  of  Cl.  These  substances  in  turn,  by 
substitution  of  alcoholic  radicals,  or  of  atoms  of  elements,  for  atoms 
of  Cl,  give  rise  to  other  derivatives.* 

Action  on  the  Economy. — Ether  is  largely  used  in  medicine  for 
producing  anaesthesia,  either  locally  by  diminution  of  temperature, 
due  to  its  rapid  evaporation,  or  generally  by  inhalation.  When  taken 
in  overdoses,  it  causes  death,  although  it  is  by  no  means  as  liable  to 
give  rise  to  fatal  accidents  as  is  chloroform.  Patients  suffering  from 
an  overdose  may,  in  the  vast  majority  of  cases,  be  resuscitated  by 
artificial  respiration  and  the  induced  current,  one  pole  to  be  applied 
to  the  nape  of  the  neck,  and  the  other  carried  across  the  body  just 
below  the  anterior  attachments  of  the  diaphragm. 

In  cases  of  death  from  ether  the  odor  is  generally  well  marked  in 
the  clothing  and  surroundings,  and  especially  on  opening  the  thoracic 
cavity.  In  the  analysis  it  is  sought  for  in  the  blood  and  lungs  at  the 

same  time  as  chloroform  (p.  235). 

CH2\ 
Ethylene  Oxid —  I        O — is  a  cyclic  ether  corresponding  to  glycol: 

CH2/ 

CH2OH.CH2OH=(CH2)2O+H20,  as  ethyl  oxid  corresponds  to  ethylic 
alcohol:  2CH3,CH2.OH=(C2H5)2O+H2O.  It  is  prepared  by  the 
action  of  caustic  potash  on  ethylene  chlorhydrin  (p.  315) :  CEbOH.- 
CH2C1+KHO=(CH2)2O+KC1+H2O.  It  is  a  volatile  liquid,  boils 
at  13.5°  (54.3°  F.),  is  neutral  in  reaction  and  mixes  with  water.  It 
unites  with  H2O  to  form  glycol,  and  with  HC1  to  regenerate  ethylene 
chlorhydrin.  Nascent  H  converts  it  into  ethyl  alcohol.  Aliphatic 
ethers  are  also  derivable  from  the  glycols,  such  as  glycol  diethyl 
ether,  C2H5.O.C2H4.O.C2H5,  and  diethylene  glycol  ether,  HOCH2.- 
CH2.O.CH2.CH2OH. 


302  MANUAL    OF    CHEMISTRY 

ANHYDRIDS. 

The  organic  anhydrids  are  the  oxids  of  the  acid  radicals  (acidyls) ; 
and  bear  the  same  relation  to  the  acids  that  the  simple  ethers  bear  to 
the  alcohols: 

CHa.COOH  CH3.CH2OH 

Acetic  acid.  Ethylic  alcohol. 

CH3.CO\n  CH3.CH2\n 

CH3.CO/U  CH3.CH2/U 

Acetic  anhydrid.  Ethylic  ether. 

The  two  oxids  of  carbon  are  also  anhydrids  in  that  they  combine 
with  water  to  produce  acids,  or,  what  amounts  to  the  same  thing, 
with  KHO  to  form  the  K  salts,  thus  : 

CO  +          KHO  H.COOK 

Carbon  Potassium  Potassium 

monoxid.  hydroxid.  formate. 

C02  +          KHO  0:C\OK 

Carbon  Potassium  Monopotassic 

dioxid.  hydroxid,  carbonate. 


OXIDS    OF    CARBON. 

Carbon  Monoxid — Carbonous  oxid — Carbonic  oxid — CO — 28 — is 
formed:  (1)  By  burning  C  with  a  limited  supply  of  air.  (2)  By 
passing  dry  carbon  dioxid  over  red-hot  charcoal.  (3)  By  heating 
oxalic  acid  with  sulfuric  acid  C2O4H2  =  H2O-hCO-|-CO2;  and  passing 
the  gas  through  sodium  hydroxid  to  separate  CO2.  (4)  By  heating 
potassium  ferrocyanid  with  E^SCU. 

It  is  a  colorless,  tasteless  gas:  sp.  gr.  0.9678A;  very  sparingly 
soluble  in  H2O  and  in  alcohol.  It  burns  in  air  with  a  blue  flame  to 
CO2,  and  it  forms  explosive  mixtures  with  air  and  oxygen.  It  is  a 
valuable  reducing  agent,  and  is  used  for  the  reduction  of  metallic 
oxids  at  a  red  heat.  Ammoniacal  solutions  of  the  cuprous  salts 
absorb  it  readily.  Being  non- saturated,  it  unites  readily  with  O  to 
form  CO2,  and  with  Cl  to  form  COC12,  the  latter  a  colorless,  suffo- 
cating gas,  known  as  phosgene,  or  carbonyl  chlorid,  which  is  of 
service  in  the  formation  of  acid  chlorids  and  anhydrids  (p.  310)  and 
in  a  variety  of  other  syntheses. 

Toxicology. — Carbon  monoxid  is  an  exceedingly  poisonous  gas, 
and  is  the  chief  toxic  constituent  of  the  gases  given  off  from  blast- 
furnaces, from  defective  flues,  from  open  coal  or  charcoal  fires;  and  of 
illuminating  gas. 

Poisoning  by  CO  may  occur  in  several  ways.  By  inhalation  of 
the  gases  discharged  from  blast-furnaces  and  from  copper -furnaces, 
the  former  containing  25  to  32  per  cent,  and  the  latter  13  to  19  per 


ANHYDEIDS  303 

cent,  of  CO.  By  the  fumes  given  off  from  charcoal  burned  in  a  con- 
fined space,  which  consists  of  a  mixture  of  the  two  oxids  of  carbon, 
the  dioxid  predominating  largely,  especially  when  the  combustion  is 
most  active.  The  following  is  the  composition  of  an  atmosphere 
produced  by  burning  charcoal  in  a  confined  space,  and  which  proved 
rapidly  fatal  to  a  dog:  oxygen,  19.19;  nitrogen,  76.62;  carbon  dioxid, 
4.61;  carbon  monoxid,  0.54;  marsh-gas,  0.04.  Obviously  the  dele- 
terious effects  of  charcoal-fumes  are  more  rapidly  fatal  in  proportion 
as  the  combustion  is  imperfect  and  the  room  small  and  ill- ventilated. 

A  fruitful  source  of  CO  poisoning,  sometimes  fatal,  but  more  fre- 
quently producing  languor,  headache  and  debility,  is  to  be  found  in 
the  stoves,  furnaces,  etc.,  used  in  heating  our  dwellings  and  other 
buildings,  especially  when  the  fuel  is  anthracite  coal.  This  fuel  pro- 
duces in  its  combustion,  when  the  air  supply  is  not  abundant,  consid- 
erable quantities  of  CO,  to  which  a  further  addition  may  be  made  by 
the  reduction  of  the  dioxid,  also  formed,  in  passing  over  red-hot  iron. 

Of  late  years  cases  of  fatal  poisoning  by  illuminating  gas  are  of 
very  frequent  occurrence,  caused  either  by  accidental  inhalation,  by 
inexperienced  persons  blowing  out  the  gas,  or  by  suicides.  The  most 
actively  poisonous  ingredient  of  illuminating  gas  is  CO,'  which  exists 
in  the  ordinary  coal-gas  in  the  proportion  of  4  to  7.5  per  cent.,  and 
in  water-gas,  made  by  decomposing  superheated  steam  by  passage 
over  red-hot  coke,  and  subsequent  charging  with  vapor  of  hydrocar- 
bons, in  the  large  proportion  of  30-35  per  cent. 

The  method  in  which  CO  produces  its  fatal  effects  is  by  forming 
with  the  blood-coloring  matter  a  compound  which  is  more  stable  than 
oxyhasmoglobin,  and  thus  causing  asphyxia  by  destroying  the  power 
of  the  blood  corpuscles  of  carrying  O  from  the  air  to  the  tissues. 
This  compound  of  CO  and  hemoglobin  is  quite  stable,  and  hence  the 
symptoms  of  this  form  of  poisoning  are  very  persistent,  lasting  until 
the  place  of  the  coloring-matter  thus  rendered  useless  is  supplied  by 
new  formation.  The  prognosis  is  very  unfavorable  when  the  amount 
of  the  gas  inhaled  has  been  at  all  considerable,  the  treatment  usu- 
ally followed,  i.e.,  artificial  respiration  and  inhalation  of  O,  failing  to 
restore  the  altered  coloring  matter.  There  would  seem  to  be  no  form 
of  poisoning  in  which  transfusion  of  blood  is  more  directly  indicated 
than  in  that  by  CO,  but  it  has  been  found  to  be  detrimental  rather 
than  beneficial. 

Detection  after  death. — The  blood  of  those  asphyxiated  by  CO  is 
persistently  bright-red  in  color.  When  suitably  diluted  and  examined 
with  the  spectroscope,  it  presents  an  absorption  spectrum  (No.  6, 
fig.  37,  p.  547)  of  two  bands  similar  to  that  of  oxyhsemoglobin  (No. 
3,  fig.  37),  but  in  which  the  two  bands  are  more  equal  and  somewhat 
nearer  the  violet  end  of  the  spectrum.  Owing  to  the  greater  stability 


304  MANUAL    OF    CHEMISTRY 

of  the  CO  compound,  its  spectrum  may  be  readily  distinguished  from 
that  of  the  O  compound  by  the  addition  of  a  reducing  agent  (an  am- 
moniacal  solution  of  ferrous  tartrate),  which  changes  the  spectrum 
of  oxyhaemoglobin  to  the  single-band  spectrum  of  hemoglobin  (No. 
1,  fig.  37),  while  that  of  the  CO  compound  remains  unaltered,  or 
only  fades  partially. 

If  a  solution  of  caustic  soda  of  sp.  gr.  1.3  be  added  to  normal 
blood,  a  black,  slimy  mass  is  formed,  which,  when  spread  upon  a 
white  plate,  has  a  greenish-brown  color.  The  same  reagent  added  to 
blood  altered  by  CO  forms  a  firmly  clotted  mass,  which  in  thin  layers 
upon  a  white  surface  is  bright  red  in  color. 

A  piece  of  gun-cotton  upon  which  platinum-black  has  been  dusted 
fires  in  air  containing  2.5  in  1,000  of  CO. 

For  the  method  of  determining  CO  in  gaseous  mixtures,  see  p.  309. 

Carbon  Dioxid — Carbonic  anhydrid — Carbonic  acid  gas — CO2 — 
44 — is  obtained:  (1)  By  burning  C  in  air  or  O.  (2)  By  decomposing 
a  carbonate  (marble^CaCOs)  by  a  mineral  acid  (HC1  diluted  with  an 
equal  volume  of  EbO). 

At  ordinary  temperatures  and  pressures  it  is  a  colorless,  suffo- 
cating gas;  has  an  acidulous  taste;  sp.  gr.  1.529  A;  soluble  in  an 
equal  volume  of  B^O  at  the  ordinary  pressure,  much  more  soluble  as 
the  pressure  increases.  Soda  water  is  a  solution  of  carbonic  acid  in 
H2O  under  increased  pressure.  When  compressed  to  the  extent  of 
38  atmospheres  at  0°  (32°  F.);  50  atm.  at  15°  (59°  F.);  or  73  atm. 
at  30°  (86°  F.)  it  forms  a  transparent,  mobile  liquid,  by  whose  evapo- 
ration, when  the  pressure  is  relieved,  sufficient  cold  is  produced  to 
solidify  a  portion  into  a  snow-like  mass,  which,  by  spontaneous 
evaporation  in  air,  produces  a  temperature  of  — 90°  ( — 130°  F.). 

Carbon  dioxid  neither  burns  nor  does  it  support  combustion. 
When  heated  to  1,300°  (2,370°F.),  it  is  dissociated  into  CO  and  O. 
A  similar  decomposition  is  brought  about  by  the  passage  through  it 
of  electric  sparks.  When  heated  with  H  it  yields  CO  and  H2O, 
When  K,  Na,  or  Mg  is  heated  in  an  atmosphere  of  CO2,  the  gas  is 
decomposed  with  formation  of  a  carbonate  and  separation  of  carbon. 
When  caused  to  pass  through  solutions  of  the  hydroxids  of  Na,  K, 
Ca,  or  Ba,  it  is  absorbed,  with  formation  of  the  carbonates  of  those 
metals,  which,  in  the  case  of  the  last  two,  are  deposited  as  white 
precipitates.  Solution  of  potash  is  frequently  used  in  analysis  to 
absorb  CO2,  and  lime  and  baryta  water  as  tests  for  its  presence.  The 
hydroxids  mentioned  also  absorb  CO2  from  moist  air. 

Atmospheric  Carbon  Dioxid. — Carbon  dioxid  is  a  constant  con- 
stituent of  atmospheric  air  in  small  and  varying  quantities;  the  mean 
amount  in  free  country  air  being  about  4  in  10,000.  On  land  the 
amount  is  greater  by  night  than  by  day,  while,  the  reverse  is  the  case  at 


ANHYDRIDS  305 

sea.  On  land  the  green  parts  of  plants  absorb  CO2  during  the  hours 
of  sunlight,  but  not  during  those  of  darkness.  The  increase  in  the 
amount  in  air  over  large  bodies  of  water  during  the  daytime  is  due  to 
the  less  solubility  of  C(>2  in  the  surface-water  when  heated  by  the 
sun's  rays.  The  absence  of  vegetation  accounts  for  the  large  quan- 
tity of  C(>2  in  the  air  of  the  polar  regions,  and  the  same  cause,  aided 
by  an  increased  production,  for  its  excess  in  the  air  of  cities  over  that 
of  the  country. 

The  sources  of  atmospheric  C(>2  are  : 

(1)  The  respiration  of  animals. — The  expired  air  under  ordinary 
conditions  contains  about  4.5  per  cent,  by  volume  of  €62,  the  pro- 
portion being  greater  the  slower  the  respiration. 

(2)  Combustion. — The  greater  part  of  the  atmospheric  CO2  is  a 
product  of  the  oxidation  of  C  in  some  form  as  a  source  of  light  and 
heat.     In   equal  times,  an  ordinary  gas-burner  produces  nearly  six 
times  as  much  C(>2,  and  consumes  nearly  ten  times  as  much  air  as  a 
man. 

(3)  Fermentation.  —  Most   fermentations,  including   putrefactive 
changes,   are  attended    by  the   liberation  of   C(>2.     Thus,   alcoholic 
fermentation  takes  place  according  to  the  equation  : 

C6Hi2O6         =          2C2H6O         +         2CO2 
180  92  88 

and  consequently  discharges  into  the  air  88  parts  by  weight  of  CO2 
for  every  92  parts  of  alcohol  formed,  or  384  litres  of  gas  for  every 
litre  of  absolute  alcohol  obtained. 

(4)  Tellural  sources. — Volcanoes  in  activity  discharge  enormous 
quantities  of  CO2,  and,  in  volcanic  countries  the  same  gas  is  thrown 
out  abundantly  through  fissures  in  the  earth.     All  waters,  sweet  and 
mineral,   hold  this  gas  in  solution,   and   those  which  have   become 
charged  with  it  under  pressure  in  the  earth's  crust,  upon  being  re- 
lieved of  the  pressure  when  they  reach  the  surface,   discharge  the 
excess  into  the  air. 

(5)  Manufacturing  processes. — Large  quantities  of  CO2  are  added 
to  the  air  in  the  vicinity  of  lime-  and  brick-kilns,  cement-works,  etc. 

(6)  In  mines,  after  explosions  of  "fire-damp."     These  explosions 
are  caused  by  the  sudden  union  of  the  C  and  H  of  CEU,  with  the  O 
of  the  air,  and  are  consequently  attended  by  the  formation  of.  large 
volumes  of  CO2,  known  to  miners  as  after -damp. 

Constancy  of  the  amount  of  atmospheric  carbon  dioxid. — It  has  been 
roughly  estimated  by  Poggendorff  that  2,500,000,000,000  cubic  metres 
of  CO2  are  annually  discharged  into  our  atmosphere,  and  that  this 
quantity  represents  one  eighty -sixth  of  the  total  amount  at  present 
existing  therein.  This  being  the  case,  with  the  present  production, 
20 


306  MANUAL    OF    CHEMISTRY 

tke  percentage  of  atmospheric  COz  would  be  doubled  in  eighty -six 
years.  No  such  increase  has,  however,  been  observed.  The  CO2 
discharged  into  the  air  is,  therefore,  removed  from  it  about  as  fast  as 
it  is  produced.  This  removal  is  effected  in  two  ways:  (1)  by  the 
formation  of  deposits  of  earthy  carbonates  by  animal  organisms, 
corals,  mollusks,  etc.;  (2)  principally  by  the  process  of  nutrition  of 
vegetables,  which  absorb  CO2  both  by  their  roots  and  leaves,  and  in 
the  latter,  under  the  influence  of  the  sun's  rays,  decompose  it,  re- 
taining the  C,  which  passes  into  more  complex  molecules;  and  dis- 
charging a  volume  of  O  about  equal  to  that  of  the  CO2  absorbed. 

Air  contaminated  with  excess  of  carbon  dioxid,  and  its  effects  upon 
the  organism. — When,  from  any  of  the  above  sources,  the  air  of  a 
given  locality  has  received  sufficient  C(>2  to  raise  the  proportion  above 
7  in  10,000  by  volume,  it  is  to  be  considered  as  contaminated;  the 
seriousness  of  the  contamination  depending  not  only  upon  the  amount 
of  the  increase,  but  also  upon  the  source  of  the  C02.  If  the  gas  be 
derived  from  fermentation,  or  from  tellural  or  manufacturing  sources, 
it  is  simply  added  to  the  otherwise  unaltered  air,  and  the  absolute 
amount  of  oxygen  present  remains  the  same.  When,  however,  it  is 
produced  in  a  confined  space  by  the  processes  of  combustion  and 
respiration,  the  composition  of  the  air  is  much  more  seriously  modi- 
fied, as  not  only  is  there  addition  of  a  deleterious  gas,  but  a  simul- 
taneous removal  of  an  equal  volume  of  O;  hence  the  importance  of 
providing,  by  suitable  ventilation,  for  the  supply  of  new  air  from 
without  to  habitations  and  other  places  where  human  beings  are  col- 
lected within  doors,  especially  where  the  illumination  is  by  gas-lights. 

Although  an  adult  man  deoxidizes  a  little  over  100  litres  of  air  in 
an  hour,  a  calculation  of  the  quantity  which  he  would  require  in  a 
given  time  cannot  be  based  exclusively  upon  that  quantity,  as  the  de- 
oxidation  cannot  be  carried  to  completeness;  indeed,  when  the  pro- 
portion of  CO2  in  air  exceeds  five  per  cent,  it  becomes  incapable  of 
supporting  life,  while  a  much  smaller  quantity,  one  per  cent.,  is  provo- 
cative of  severe  discomfort,  to  say  the  least. 

In  calculating  the  quantity  of  air  which  should  be  supplied  to  a 
given  enclosed  space,  most  authors  have  agreed  to  adopt  as  a  basis 
that  the  percentage  of  C(>2  should  not  be  allowed  to  exceed  0.6  vol- 
ume per  1,000;  of  which  0.4  is  normally  present  in  air,  and  0.2  the 
product  of  respiration  or  combustion.  Taking  the  amount  of  CO2 
eliminated  by  an  adult  at  19  litres  (=0.7  cubic  foot)  per  hour,  a  man 
will  have  brought  the  air  of  an  air-tight  space  of  100  cubic  metres 
(=3t500  cubic  feet)  up  to  the  permissible  maximum  of  impurity  in 
an  hour. 

Practically,  owing  to  the  imperfect  closing  of  doors  and  windows, 
and  to  ventilation  by  chimneys,  inhabited  spaces  are  never  hermeti- 


ANHYDRIDS 


307 


cally  closed,  and  a  less  quantity  of  air-supply  than  would  be  required 
in  an  air-tight  space  will  suffice. 

A  sleeping-room  occupied  by  a  single  person  should  have  a  cubic 
space  of  30  to  50  cubic  metres  (=1,050  to  1,800  cubic  feet),  condi- 
tions which  are  fulfilled  in  rooms  measuring  10X13X8  feet  and  13  X 
15.6X9  feet. 

In  calculating  the  space  of  dormitories  to  be  occupied  by  several 
healthy  people,  the  smallest  air-space  that  should,  under  any  circum- 
stances, be  allowed,  is  12  cubic  metres  (=420  cubic  feet)  for  each 
person.  To  determine  the  number  of  individuals  that  may  sleep  in  a 
room,  multiply  its  length,  width  and  height  together,  and  divide  the 
product  by  420  if  the  measurement  be  in  feet,  or  by  12  if  it  be  in 
metres.  Thus,  a  dormitory  40  feet  long,  20  feet  wide  and  10  feet 
high  is  fitted  for  the  accommodation  of  19  persons  at  most ;  for 
40X20X10=8,000  and  *fff-  =19.05. 

As  a  rule,  in  places  where  many  persons  are  congregated,  it  is 
necessary  to  resort  to  some  scheme  of  ventilation  by  which  a  suffi- 
cient supply  of  fresh  air  shall  be  introduced  and  the  vitiated  air 
removed,  the  quantity  to  be  supplied  varying  according  to  circum- 
stances. Experiment  has  shown  that,  in  order  to  keep  the  air  pure 
to  the  senses,  the  quantity  of  air  which  must  be  supplied  per  head 
and  per  hour  in  temperate  climates  is  as  shown  in  the  table : 


Situation. 

Cubic 
metres. 

Cubic 
feet. 

Situation. 

Cubic 
metres. 

Cubic 
feet. 

Barracks  (day  time)  

35 

70 

1,236 
2  472 

Hospital  wards  (surgical)  .   .   . 

170 
170 

6,004 
6  004 

Workshops  (mechanical)      .    - 

70 
35 

2,472 
1  236 

Mines,  metaliferous     .... 

150 
170 

5,297 
6  004 

85 

3*002 

The  amounts  given  are  the  smallest  permissible,  and  should  be 
exceeded  wherever  practicable. 

Lights. — Each  cubic  foot  of  illuminating  gas  consumes  in  its  com- 
bustion a  quantity  of  O  equal  to  that  contained  in  7.14  cubic  feet  of 
air,  and  produces  0.8  cubic  feet  of  CO2,  besides  a  large  quantity  of 
watery  vapor,  and  less  amounts  of  H2SO4,  862  and  sometimes  CO;  and 
an  ordinary  gas-burner  consumes  about  three  feet  per  hour.  It  is  ob- 
vious, therefore,  that  a  much  larger  quantity  of  pure  air  must  be 
furnished  to  maintain  the  atmosphere  of  an  apartment  at  the  standard 
of  0.6  per  1,000  of  C(>2,  when  the  vitiation  is  produced  by  the  com- 
bustion of  gas,  than  when  it  is  the  result  of  the  respiration  of  a 
human  being,  and  that  to  such  an  extent  that  a  single  three -foot 
burner  requires  a  supply  of  air  which  would  be  sufficient  for  six 
human  beings. 


308  MANUAL    OF    CHEMISTRY 

In  theaters  the  contamination  of  the  air  by  the  burning  of  gas 
should  be  entirely  eliminated  by  the  use  of  electricity  or  by  placing 
the  gas-burners  either  under  the  dome  ventilator,  or  in  boxes  which 
open  to  the  air  of  the  house  only  below  the  level  of  the  burner,  and 
which  are  in  communication  with  a  ventilating- shaft. 

When  artificial  illumination  is  obtained  from  lamps  or  candles,  or 
from  gas  in  small  quantity  and  for  a  short  time,  the  contamination 
of  the  air  is  sufficiently  compensated  by  the  ventilation  through  im- 
perfect closing  of  the  windows.  A  room  without  a  window  should 
never  be  used  for  human  habitation. 

One  important  advantage  of  the  electric  light  is  that  it  consumes 
no  O  and  produces  no  C(>2. 

Although,  by  the  combustion  of  fuel,  O  is  consumed  and  C(>2  pro- 
duced, heating  arrangements  only  become  a  source  of  vitiation  of  air 
when  they  are  improperly  constructed.  Indeed,  in  the  majority  of 
cases,  if  properly  arranged,  they  are  the  means  of  ventilation,  either 
by  aspirating  the  vitiated  air  of  the  apartment,  or  by  the  introduction 
of  air  from  without. 

Action  on  the  Economy. — An  animal  introduced  into  an  atmos- 
phere of  pure  CO2  dies  almost  instantly,  and  without  entrance  of  the 
gas  into  the  lungs,  death  resulting  from  spasm  of  the  glottis,  and 
consequent  apnoea. 

When  diluted  with  air,  the  action  of  CO2  varies  according  to  its 
proportion,  and  according  to  the  proportion  of  O  present. 

When  the  proportion  of  O  is  not  diminished,  the  poisonous  action 
of  C(>2  is  not  as  manifest,  in  equal  quantities,  as  when  the  air  is 
poorer  in  oxygen.  An  animal  will  die  rapidly  in  an  atmosphere  com- 
posed of  21  per  cent.  O,  59  per  cent.  N,  and  20  per  cent.  CO2  by  vol- 
ume; but  will  live  for  several  hours  in  an  atmosphere  whose  compo- 
sition is  40  per  cent.  O,  37  per  cent.  N,  23  per  cent.  CO2.  If  C02  be 
added  to  normal  air,  of  course  the  relative  quantity  of  O  is  slightly 
diminished,  while  its  absolute  quantity  remains  the  same.  This  is 
the  condition  of  affairs  existing  in  nature  when  the  gas  is  discharged 
into  the  air;  under  these  circumstances  an  addition  of  10-15  per  cent, 
of  CO2  renders  an  air  rapidly  poisonous,  and  one  of  5-8  per  cent,  will 
cause  the  death  of  small  animals  more  slowly.  Even  a  less  pro- 
portion than  this  may  become  fatal  to  an  individual  not  habituated. 

When  present  in  large  proportion,  C02  produces  immediate  loss  of 
muscular  power,  and  death  without  a  struggle;  when  more  dilute,  a 
sense  of  irritation  of  the  larynx,  drowsiness,  pain  in  the  head,  giddi- 
ness, gradual  loss  of  muscular  power,  and  death  in  coma. 

If  the  C02  present  in  air  be  produced  by  respiration,  or  com- 
bustion, the  proportion  of  O  is  at  the  same  time  diminished,  and 
much  smaller  absolute  and  relative  amounts  of  the  poisonous  gas  will 


;    ANHYDRIDS  309 

produce  the  effects  mentioned  above.  Thus,  an  atmosphere  con- 
taining in  volumes  19.75  per  cent.  O,  74.25  per  cent.  N,  6  per  cent. 
CO2,  is  much  more  rapidly  fatal  than  one  composed  of  21  per  cent. 
O,  59  per  cent.  N,  20  per  cent.  CO2.  With  a  corresponding  reduc- 
tion of  O,  5  per  cent,  of  CO2  renders  an  air  sufficiently  poisonous  to 
destroy  life;  2  per  cent,  produces  severe  suffering;  1  per  cent,  causes 
great  discomfort,  while  0.1  per  cent.,  or  even  less,  is  recognized  by  a 
sense  of  closeness. 

The  treatment  in  all  cases  of  poisoning  by  C(>2  consists  in  the 
inhalation  of  pure  air  (to  which  an  excess  of  O  may  be  added),  aided, 
if  necessary,  by  artificial  respiration,  the  cold  douche,  galvanism,  and 
friction. 

Detection  of  Carbon  Dioxid  and  Analysis  of  Confined  Air. — Car- 
bon dioxid,  or  air  containing  it,  causes  a  white  precipitate  when 
caused  to  bubble  through  lime  or  baryta  water.  Normal  air  contains 
enough  of  the  gas  to  form  a  scum  upon  the  surface  of  these  solutions 
when  exposed  to  it. 

It  was  at  one  time  supposed  that  air  in  which  a  candle  continued 
fco  burn  was  also  capable  of  maintaining  respiration.  This  is,  how- 
ever, by  no  means  necessarily  true.  A  candle  introduced  into  an 
atmosphere  in  which  the  normal  proportion  of  0  is  contained,  burns 
readily  in  the  presence  of  8  per  cent,  of  C02;  is  perceptibly  dulled  by 
10  percent.;  is  usually  extinguished  with  13  percent.;  always  ex- 
tinguished with  16  per  cent.  Its  extinction  is  caused  by  a  less  pro- 
portion of  CO2,  4  per  cent.,  if  the  quantity  of  0  be  at  the  same  time 
diminished.  Moreover,  a  contaminated  atmosphere  may  not  contain 
enough  CO2  to  extinguish,  or  perceptibly  dim  the  flame  of  a  candle, 
and  at  the  same  time  contain  enough  of  the  monoxid  to  render  it 
fatally  poisonous  if  inhaled. 

The  presence  of  CO2  in  a  gaseous  mixture  is  determined  by  its 
absorption  by  a'solution  of  potash;  its  quantity  either  by  measuring 
the  diminution  in  bulk  of  the  gas,  or  by  noting  the  increase  in  weight 
of  an  alkaline  solution. 

To  determine  the  proportions  of  the  various  gases  present  in  air 
the  apparatus  shown  in  Fig.  36  is  used.  A  is  an  aspirator  of  known 
capacity,  filled  with  water  at  the  beginning  of  the  operation.  It  con- 
nects by  a  flexible  tube  from  its  upper  part  with  an  absorbing  appa- 
ratus consisting  of  a,  a  U-shaped  tube  containing  fragments  of 
pumice-stone,  moistened  with  IbSOi;  by  the  increase  in  weight  of 
this  tube  the  weight  of  watery  vapor  in  the  volume  of  air  drawn 
through  by  the  aspirator  is  determined;  &,  a  Liebig's  bulb  filled  with 
a  solution  of  potash;  c,  a  U-tube  filled  with  fragments  of  pumice 
moistened  with  112864;  &  and  c  are  weighed  together  and  their  in- 
crease in  weight  is  the  weight  of  CC>2  in  the  volume  of  air  operated 


310 


MANUAL    OP    CHEMISTRY 


on.  Every  gram  of  increase  in  weight  represents  0.50607  litre,  or 
31.60356  cubic  inches;  d  is  a  tube  of  difficultly  fusible  glass,  filled 
with  black  oxid  of  copper  and  heated  to  redness;  e  is  a  U-tube  filled 
with  pumice  moistened  with  H2SO4;  its  increase  in  weight  represents 
BfoO  obtained  from  decomposition  of  CEU.  Every  gram  of  increase 
in  weight  of  e  represents  0.444  gram,  or  0.621  litre,  or  38.781  cubic 
inches  of  marsh-gas;  /and  g  are  similar  to  b  andc,  and  their  increase 


FIG.  36. 

in  weight  represents  C02  formed  by  oxidation  of  CO  and  CH4  in  d. 
From  this  the  amount  of  CO  is  thus  calculated  :  First,  2.75  grams 
are  deducted  from  the  increase  of  weight  of  /  and  g  for  each  gram  of 
CILt  found  by  e;  of  the  remainder,  every  gram  represents  0.6364 
gram,  or  0.5085  litre,  or  31.755  cubic  inches  of  CO.  The  air  is 
drawn  through  the  apparatus  by  opening  the  stopcock  of  A  to  such 
an  extent  that  about  thirty  bubbles  a  minute  pass  through  b. 


ACIDYL    ANHYDRIDS. 

The  acidyl  anhydrids  of  the  monobasic  acids  are  produced  by  the 
action  of  the  acidyl  chlorids  upon  anhydrous  salts:  C2HaO.OK-h 
C2H3O.Cl=(C2H3O)2O-f  KC1;  or  by  the  action  of  phosphorus  oxy- 
chlorid  upon  the  alkali  salts  of  the  acids.  In  this  method  of  formation 
the  acidyl  chlorid  is  first  produced:  2C2H3O.OK+POCl3=2C2H3O.Cl+ 
POsK+KCl;  and  this  acts  upon  an  excess  of  the  salt  according  to 
the  above  equation. 

Acetic  Anhydrid — ^HsOhO — is  a  pungent  liquid  which  boils 
at  137°  (278.6°  F.).  It  is  formed  by  the  general  methods  and 
also  by  heating  lead  acetate  with  carbon  disulfid  at  165°  (329°  F.). 


ACIDYL    HALOIDS  — ESTERS— COMPOUND    ETHERS  311 

It   serves    for  the    introduction   of    the   radical    acetyl    into   other 
molecules. 

Anhydrids  of  the  oxyacids  and  of  the  pure  dicarboxylic  acids  also 
exist. 

ACIDYL  HALOIDS. 

These  compounds,  also  known  as  haloid  anhydrids,  are  the  halo- 
gen compounds  of  the  acidyls.  They  are  produced:  (1)  by  the 
action  of  the  phosphorus  haloids  upon  the  acids  or  their  salts  (see 
above) ;  (2)  by  the  action  of  phosgene  upon  the  acids,  or  their  salts: 
COC12  +  CH3.COOH  =  CH3.CO.C1+CO2+HC1;  (3)  by  the  action  of 
phosphorus  pentoxid  upon  the  acids  in  presence  of  hydrochloric  acid: 
3CH3.COOH+3HC1+P2O5  =  3CH3.CO.C1+2PO4H3;  or  (4)  by  the 
action  of  chlorin  upon  the  aldehydes:  C12+CH3.CO.H=CH3.CO.C1+ 
HCL 

Acetyl  Chlorid — CH3.CO.C1 — is  a  colorless,  pungent  liquid,  which 
boils  at  55°  (131°  F.)  It  is  decomposed  by  water  with  formation  of 
acetic  and  hydrochloric  acids.  With  acetic  acid  it  forms  acetic  anhy- 
drid.  It  is  used  to  produce  acetyl  derivatives. 


ESTERS— COMPOUND  ETHERS. 

As  the  alcohols  resemble  the  mineral  bases,  and  the  organic  acids 
resemble  those  of  mineral  origin,  so  the  esters  are  similar  in  constitu- 
tion to  the  salts,  being  formed  by  the  double  decomposition  of  an  alco- 
hol with  an  acid,  mineral  or  organic,  as  a  salt  is  formed  by  double 
decomposition  of  an  acid  and  a  mineral  base,  the  radical  playing  the 
part  of  an  atom  of  corresponding  valence  : 


o      = 

Potassium  hydroxid.  Nitric  acid.  Water.  Potassium  nitrate. 

(N02nQ  H\ft  _,_  (N02) 

H  J 


(C2H5)' 

Ethyl  nit 
(alcohol).  (nitric  ether). 


Ethyl  hydroxid  Nitric  acid.  Water.  Ethyl  nitrate 

ohol). 


Therefore  the  esters  are  acids  whose  hydrogen  has  been  par- 
tially or  completely  displaced  by  a  hydrocarbon  radical  or  radicals. 

Some  of  the  esters  still  contain  a  portion  of  the  acid  hydrogen 
which,  being  replaceable  by  another  radical  or  by  a  metal,  commu- 
nicates acid  qualities  to  the  substance,  which  is  at  the  same  time  an 
ester  and  a  true  acid.  Or  di-  and  polyhydric  alcohols,  in  combining 
with  acids  of  inferior  basicity,  may  form  esters  which  still  retain 
alcoholic  hydroxyls,  and  which  are,  therefore,  alcohol-esters. 


312  MANUAL    OF    CHEMISTRY 

ESTERS    OP    THE    MONOHYDRIC    ALCOHOLS. 

These  esters  are  produced  : 

(1)  By  the  action  of  the  acid  upon  the  alcohol:  H2SO4+CH3.CH2- 
OH=CH3.CH2.HSO4+H2O;   or  H2SO4+2CH3.CH2OH=(CH3.CH2)2- 
SO4+2H2O. 

(2)  By  the  action  of  the  corresponding  haloid  esters  upon  the 
silver  salt  of  the  acid  :  AgNO3+C2H5I=AgI+C2H5.NO3. 

(3) By  the  action  of  the  acidyl  chlorids  upon  the  sodium  deriva- 
tives of  the  alcohols,  and  in  some  instances  upon  the  alcohols  them- 
selves: C2H3O.Cl+C2H5.O.Na=NaCl-hC2H3O2.C2H5. 

All  esters  are  decomposed  into  acid  and  alcohol  by  the  action  of 
water  at  high  temperatures,  or  of  caustic  potash  or  soda  :  (C2H5)NO3- 
+KHO=KN03-fC2H5HO. 

As  this  decomposition  is  analogous  to  that  utilized  in  the  manu- 
facture of  soap  (p.  318),  it  is  known  as  saponification,  and  whenever 
an  ester  is  so  decomposed  it  is  said  to  be  saponified.  When  the  de- 
composition is  effected  by  H2O  the  free  acid  and  the  alcohol  are 
formed,  and  it  is  known  as  hydrolysis  (p.  70):  (C2H5)C2H3O2+ 
H2O=C2H5.HO+H.C2H3O2. 

Ethyl  Nitrate— Nitric  ether— ^l}0— 91.—  A  colorless  liquid; 
has  a  sweet  taste  and  bitter  after-taste;  sp.  gr.  1.112  at  17°  (62.6° 
F.);  boils  at  85°  (185°  F.);  gives  off  explosive  vapors.  Prepared 
by  distilling  a  mixture  of  HNO3  and  C2HeO  in  the  presence  of  urea. 

Ethyl  Nitrite— Nitrous  ether— c™ } 0— 75— -is  prepared  by  di- 
recting nitrous  fumes  into  alcohol,  contained  in  a  retort  connected 
with  a  well -cooled  receiver. 

It  is  a  yellowish  liquid;  has  an  apple -like  odor,  and  a  sharp, 
sweetish  taste:  sp.  gr.  0.947;  boils  at  18°  (64.4°  F.);  gives  off  in- 
flammable vapor;  very  sparingly  soluble  in  H20;  readily  soluble  in 
alcohol  and  ether.  It  is  decomposed  by  warm  H2O,  by  alkalies,  by 
H2SO4,  H2S,  and  the  alkaline  sulfids,  and  is  liable  to  spontaneous 
decomposition,  especially  in  the  presence  of  H2O.  Its  vapor  produces 
anaesthesia,  and  it  exists  in  alcoholic  solution  in  Spiritus  aetheris 
nitrosi  (U.  S.;  Br.). 

Ethyl  Sulfates—  (C2H5)HSO4=^^  sulfuric  or  sulfovinic  acid 
and  (C2H5)2SO4— Ethyl  sulfate — Sulfuric  ether. 

Ethyl-sulfuric  Acid — C2H]jo/S02 — is  formed  as  an  intermediate 
product  in  the  manufacture  of  ethylic  ether  (p.  300) .  It  is  a  colorless, 
syrupy,  highly  acid  liquid;  sp.  gr.  1.316;  soluble  in  water  and  alco- 
hol in  all  proportions,  insoluble  in  ether. 

It  decomposes  slowly  at  ordinary  temperatures,  more  rapidly  when 
heated.  When  heated  with  alcohol,  it  yields  ethylic  ether  and  H2SO4. 


ESTERS  —  COMPOUND    ETHERS  313 


When  heated  with  EbO,  it  yields  alcohol  and  EbSCU.  It  forms  crys- 
talline salts,  known  as  sulfovinates,  or  sulfethylates,  one  of  which, 
sodium  sulfovinate  (C2Hs)NaS04,  has  been  used  in  medicine.  It  is 
a  white,  deliquescent  solid;  soluble  in  H2O. 

Ethyl  Sulfate  —  (C2H5)2SO4  —  the  true  sulfuric  ether,  is  obtained 
by  passing  vapor  of  SOa  into  pure  ethylic  ether,  thoroughly  cooled. 
It  is  a  colorless,  oily  liquid;  has  a  sharp,  burning  taste,  and  the  odor 
of  peppermint;  sp.  gr.  1.120.  It  cannot  be  distilled  without  decom- 
position. With  EbO  it  forms  sulfovinic  acid. 

Sulfurous  and  Hyposulfurous  Esters.  —  These  compounds  have 
recently  assumed  medical  interest  from  their  relationship  to  mer- 
captan,  sulfonal  and  a  number  of  aromatic  derivatives  used  as 
medicines. 

There  exist  two  isomeric  sulfurous  acids  (p.  97),  both  of  which 
yield  neutral  esters,  but  only  one  of  which,  the  unsymmetrical, 

O/S\OH>  f°rms  acid  esters.  These  acid  esters  are  known  as  sulfonic 
acids.  (See  Aromatic  sulfonic  acids,  mercaptan,  sulfones,  sulfonal.) 
Diethyl  Sulfite  —  (€2115)  2863  —  is  produced  by  the  action  of  thionyl 
chlorid  on  absolute  alcohol  :  SOC12+2C2H5HO=SO3(C2H5)2+2HC1. 
It  is  a  colorless  liquid,  having  a  powerful  odor:  sp.  gr.  1.085,  boils 
at  161°  (321.8°  F.).  H2O  decomposes  it  into  alcohol  and  sulfurous 
acid. 

Ethyl  Sulfonic  Acid—  SO^lf5—  is  formed  by  tne  action  of 
ethyl  iodid  on  potassium  sulfite:  C2H5I+S03K2=C2H5.SO2OK-|-KI. 
It  forms  salts  and  esters. 

Sulfinic    Acids  —  are    the    acid    esters    of    hyposulfurous    acid 

/TT 

SOx'  QJJ   and  are  analogous  to  the  sulfonic  acids. 

Ethyl  Acetate  —  Acetic  ether  —  ^Ether  aceticus  —  (U.  S.)  — 
CoHs/O  —  ig  obtained  by  distilling  a  mixture  of  sodium  acetate,  alco- 
hol and  £[2804;  or  by  passing  carbon  dioxid  through  an  alcoholic 
solution  of  potassium  acetate. 

It  is  a  colorless  liquid,  has  an  agreeable,  ethereal  odor:  boils  at 
74°  (165.2°  F.)  ;  sp.  gr.  0.89  at  15°  (59°  F.)  ;  soluble  in  6  pts.  water, 
and  in  all  proportions  in  methyl  and  ethyl  alcohols  and  in  ether;  a 
good  solvent  of  essences,  resins,  cantharidin,  morphin,  gun  cotton, 
and  in  general,  of  substances  soluble  in  ether;  burns  with  a  yellowish- 
white  flame.  Chlorin  acts  energetically  upon  it,  producing  products 
of  substitution,  varying  according  to  the  intensity  of  the  light  from 
C4H6C12O2  to  C4C18O2. 

Ethyl  Aceto-acetate  —  Aceto-acetic  ester  —  CH3.CO.CH2.COO- 
(C2H5)  —  is  the  most  important  representative  of  the  class  of  /3-ketonic 
acid  esters  (p.  298),  which  are  important  synthetic  reagents.  It  is 


314  MANUAL    OF    CHEMISTRY 

prepared  by  dissolving  6  pits,  of  metallic  sodium  in  200  pts.  of  anhy- 
drous ethyl  acetate,  distilling  off  the  excess  of  the  ester,  mixing  the 
residue  with  50%  acetic  acid  in  slight  excess,  decanting  the  oil 
which  separates,  and  fractioning. 

The  formation  of  aceto-  acetic  ester  in  this  process  occurs  in  sev- 
eral reactions,  the  sum  of  which  may  be  expressed  by  the  equation: 
2CH3.COO  (C2H5)  =  CH3.CO.CH2.COO  (C2H5)  +  CH3.CH2OH  ;  two 
molecules  of  ethyl  acetate  forming  one  molecule  of  aceto  -acetic  ester 
and  one  of  ethylic  alcohol.  In  one  stage  of  the  reaction  sodium  acts 
upon  ethyl  acetate  to  form  ethyl  acetyl-sodacetate,  sodium  ethylate 
and  hydrogen:  2CH3.COO(C2H5)+Na2=CH3.CO.CHNa.COO(C2H5)- 
-hC2H5.O.Na+H2.  In  another,  sodium  ethylate  acts  upon  ethyl  ace- 
tate to  form  ethyl  acetyl-sodacetate  and  ethylic  alcohol:  2CHs.COO- 


and,  when  the  operation  is  properly  conducted,  little  or  no  hydrogen  is 
evolved,  because  that  produced  in  the  above  reaction  acts  with  sodium 
upon  ethyl  acetate  to  form  sodium  ethylate:  CH3.COO(C2H5)+Na2-f- 
H2=2C2H5.O.Na.  The  aceto-acetic  ester  is  liberated  from  its  sodium 
derivative  by  acetic  acid:  CH3.CO.CHNa.COO(C2H5)+CH3.COOH= 
CH3.COONa+CH3.CO.CH2.COO(C2H5). 

Other  esters  of  /3-ketonic  acids  are  derived  from  ethyl  acetyl- 
sodacetate  by  the  action  of  alkyl  iodids.  Thus:  CH3.CO.CHNa.COO- 
(C2H5)H-CH3I=CH3.CO.CH(CH3).COO(C2H5)-fNaI;  then,  2CH3.- 
CO.CH.(CH3).COO(C2H5)+Na2  =  2CH3.CO.CNa(CH3).COO(C2H5)- 
+  H2  ;  and  CH3.CO.CNa  (CH8).COO  (C2H5)  +  CH3I  =  CH3.CO.C- 
(CH3)2.COO(C2H5)+NaI. 

Heating  with  dilute  alkalies  decomposes  the  /?-ketonic  esters,  with 
formation,  either  of  ketones  :  CH3.CO.CH2.COO(C2H5)-f  2KHO= 
CH3.CO.CH3+C03K2+C2H5.OH;  or  of  acetates  and  salts  of  higher 
acids  of  the  same  series:  CH3.CO.CH(CH3).COO(C2H5)+2KHO= 
CHg.COOK-f  CH3.CH2.COOK+C2H5.OH.  Nascent  hydrogen  con- 
verts them  into  the  corresponding  /3-oxy-  acids.  Thus  ethyl  aceto- 
acetate  yields  ethyl  /3-oxy-butyrate  :  CH3.CO.CH2.COO(C2H5)  + 
H2=CH3.CHOH.CH2.COO(C2H5). 

Acetyl-  acetic  ester  is  utilized  in  a  great  number  of  syntheses  of 
both  aromatic  and  aliphatic  compounds.  It  is  a  colorless  liquid,  b. 
p.  181°  (357.8°  F.),  having  a  pleasant  odor,  and  almost  insoluble  in 
water.  It  is  colored  violet  by  ferric  chlorid. 

Amyl  Nitrate  —  c5n!i}o  —  obtained  by  distilling  a  mixture  of 
HNO3  and  amylic  alcohol  in  the  presence  of  a  small  quantity  of  urea. 
It  is  a  colorless,  oily  liquid;  sp.  gr.  0.994  at  10°  (50°  F.);  boils  at 
148°  (298.  4°  F.)  with  partial  decomposition. 

Amyl    Nitrite—  Amyl    nitris    (U.  S.)—  c          O—  117—  prepared 


ESTERS  —  COMPOUND    ETHERS  315 

by  directing  nitrous  fumes  into  amyl  alcohol,  contained  in  a  retort 
heated  over  a  water -bath;  purifying  the  distillate  by  washing  with 
an  alkaline  solution,  and  rectifying. 

It  is  a  slightly  yellowish  liquid;  sp.  gr.  0.877;  boils  at  95°  (203° 
F. ) .  Its  vapor,  which  is  orange -colored,  explodes  when  heated  to  260° 
(500°  F.).  It  is  insoluble  in  water  ;  soluble  in  alcohol  in  all  propor- 
tions. Alcoholic  solution  of  potash  decomposes  it  slowly,  with  forma- 
tion of  potassium  nitrite  and  ethyl  and  amyl  oxids.  When  dropped 
upon  fused  potash,  it  ignites  and  yields  potassium  valerianate. 

Amyl  Acetate — Pear  oil — c5Hu/0 — is  prepared  by  distilling  a 
mixture  of  sulfuric  acid,  amylic  alcohol  and  potassium  acetate.  It 
has  the  odor  of  pears,  is  insoluble  in  water,  soluble  in  alcohol;  and 
boils  at  125°  (257°  F.).  It  is  used  as  a  flavoring  agent  and  as  a  sol- 
vent for  celluloid. 

Cetyl  Palmitate— Cetin— Clc6^g2}  0—480— is  the  chief  constit- 
uent of  spermaceti=cetaceum  (U.  S.,  Br.),  which,  besides  cetin, 
contains  esters  of  palmitic,  stearic,  myristic,  and  laurostearic  acids; 
and  of  the  alcohols:  lethol,  C^EbO;  methol,  Ci4H3oO;  ethol,  CieH^O, 
and  stethol,  CisHasO. 

Melissyl  Palmitate  —  Melissin—C}^$°}O— 676.— Beeswax  con- 
sists mainly  of  two  substances:  cerotic  acid,  C27H53O.OH,  which  is 
soluble  in  boiling  alcohol,  and  melissyl  palmitate,  insoluble  in  that 
liquid,  united  with  minute  quantities  of  substances  which  communi- 
cate to  the  wax  its  color  and  odor.  Yellow  wax  melts  at  62°-63° 
(143.6°-145.4°  F.).  After  bleaching,  which  is  brought  about  by  ex- 
posure to  light,  air,  and  moisture,  it  does  not  fuse  below  66°  (150.8° 
F.).  China  wax,  a  white  substance  resembling  spermaceti,  is  a  vege- 
table product,  consisting  chiefly  of  ceryl  cerotate,  €27115302(0271155) . 

ESTERS    OF    DIHYDEIC    ALCOHOLS    OR    GLYCOLS. 

The  glycols  behave  as  diacid  bases  and  form  with  the  monobasic 
acids  basic  and  also  neutral  esters  :  • 

CH2OH  CH2.OOC.CH3  CH2OOC.CH3 

CH2OH  CH2OH  CH2.OOC.CH3 

Glycol.  Glycol  mono-acetate.  Glycol  diacetate. 

The  haloid  esters  of  the  glycols  are  also  basic  or  neutral.  The 
basic  compounds  are  the  glycol  halohydrins,  e.  g.,  CH^OH.CEbCl^ 
Ethylene  chlorhydrin,  produced  by  the  action  of  the  hydracids  upon 
the  glycols,  or  upon  ethylene  oxid  and  its  homologues. 

The  neutral  haloid  esters  are  among  the  haloid  derivatives  of  the 


316  MANUAL    OF    CHEMISTRY 

paraffins,  higher  than  the  first  (pp.  233-237).  They  are  produced  by 
(1)  the  substitution  of  the  halogen  in  the  paraffin  or  in  the  mono- 
halogen  paraffin;  thus  ethyl  chlorid  :  CHs.CH^Cl  yields  ethylene 
chlorid;  CH2C1.CH2C1;  (2)  by  addition  of  the  halogens  to  the  olefins 
(p.  368),  thus  ethylene:  CH2:  CH2  yields  ethylene  bichlorid;  CH2CL- 
CH2C1;  (3)  by  the  action  of  the  hydracids  upon  the  monohalogen 
olefins,  or  upon  the  glycols,  or  upon  the  glycol  chlorhydrins.  Thus 
ethylene  bichlorid  is  obtained  from  ethylene  monochlorid:  CHC1:CH2; 
ethylene  glycol:  CH2OH.CH2OH;  or  ethylene  chlorhydrin:  CH2OH.- 
CH2C1.  By  this  latter  method  two  isomeres:  CHC12.CH3  and  CH2- 
C1.CH2C1  may  be  produced. 

The  neutral  haloid  esters  of  the  glycols  are  the  starting  points  in 
the  preparation  of  the  glycols:  CH2Br.CH2Br+2AgHO=2AgBr+ 
CH2OH.CH2OH.  Nascent  hydrogen  converts  them  into  the  paraffins: 
CH2C1.CH2C1+2H2=2HC1+CH3.CH3. 

Ethylene  Chlorid— Elayl  chlorid— Dutch  liquid— CH2C1.CH2C1- 
is  obtained  by  passing  ethylene  through  a  retort  in  which  chlorin  is 
generated.  It  is  a  colorless,  oily  liquid,  has  a  sweetish  taste  and  an 
ethereal  odor;  boils  at  84°  (183.2°  F.).  It  is  capable  of  fixing  other 
atoms  of  chlorin  by  substitution  to  form  a  series  of  compounds,  the 
most  highly  chlorinated  of  which  is  carbon  trichlorid,  C2Cl6. 

ESTERS     OF    THE    TRIHYDEIC    ALCOHOLS    OR    GLYCEROLS — GLYCERIDS. 

The  glycerols  behave  as  triacid  bases,  forming  three  series  of 
esters  with  the  monobasic  acids.  These  esters  are  the  mono-,  di-, 
and  triglycerids.  Moreover,  as  two  of  the  hydroxyls  of  the  alcohol 
are  in  the  primary  groups  CH2OH,  while  the  third  is  in  the  secondary 
group,  CHOH,  there  are  two  isomeres  of  each  mono-  and  diglycerid: 


CH2OH  CH2.C2H3O2  CH2.C2H3O2  CH2.C2H3O2 

I  I  I  I  I 

CHOH  CH.CoH3O2  CHOH  CH.C2H3O<>  CH.C2H3O2 

I  I  I  I  I 

CH2OH  CH2.OH  CH2.C2H3O2  CH2OH  CH2. 


a-Monacetin.  /3-Monacetin.  a-Diacetin.  /3-Diacetin.  Triacetin. 

The  haloid  esters  are  known  as  the  glycerol  halohydrins.  Of  the 
glycerol  esters  of  mineral  oxyacids  those  of  nitric  and  phosphoric 
acids  are  of  interest. 

Trinitroglycerol  —  Nitroglycerine —  Glonoin  —  CsH^NOsh —  is 
formed  by  the  action  of  a  mixture  of  H2SOi  and  HNO3  upon  glycerol. 
It  is  an  odorless,  yellowish  oil;  has  a  sweetish  taste;  sp.  gr.  1.6;  in- 
soluble in  water,  soluble  in  alcohol  and  in  ether;  not  volatile;  crys- 
tallizes in  prismatic  needles  when  kept  for  some  time  at  0°  (32°  F.) ; 
fuses  again  at  8°  (46.4°  F.).  When  suddenly  heated,  or  when  sub- 


ESTERS  — COMPOUND    ETHERS  317 

jected  to  shock  it  is  explosively  decomposed  into  CO2;N;H20  and  O. 
Alkalies  saponify  it  to  glycerol  and  nitric  acid. 

Nitroglycerol  is  mixed  with  diatomaceous  earth  and  with  other 
inert,  absorbent  substances  in  dynamite  and  in  other  high  explosives; 
and,  combined  with  nitrocellulose,  it  forms  "smokeless  powder." 

It  is  used  in  medicine  as  a  cardiac  stimulant,  and,  in  overdose,  is 
an  active  poison,  producing  effects  somewhat  similar  to  those  caused 
by  strychnin. 

Glycero-phosphoric  Acid — C3H5(OH)2.O.PO3H2 — is  the  mono- 
glycerid  of  phosphoric  acid.  It  is  a  product  of  decomposition  of  the 
lecithins,  or  phosphorized  fats  (p.  319),  or  may  be  formed  by  mixing 
glycerol  and  metaphosphoric  acid.  It  is  a  thick  syrup,  which  is  de- 
composed into  glycerol  and  phosphoric  acid  when  heated  with  water. 
It  is  a  dibasic  acid. 

Glycerol  Esters  of  Organic  Acids. — The  triacid  glycerol  esters 
of  the  acids  of  the  acetic  and  acrylic  series  containing  an  even  number 
of  carbon  atoms  occur  in  the  animal  and  vegetable  fats  and  oils. 

Tributyrin — C3H5(O.C4H7O)3 — 302 — exists  in  butter.  It  may  also 
be  obtained  by  heating  glycerol  with  butyric  acid  and  H^SO-t.  It  is  a 
pungent  liquid,  very  prone  to  decomposition,  with  liberation  of 
butyric  acid. 

Tricaproin  —  C3H5  ( O .  C6HnO )  3  —  386  —  Tricaprylin  —  C3H5  ( O .  C8- 
Hi5O)3— 470— andTricaprin— C3H5(O.CioHi90)3— 554— exist  in  small 
quantities  in  milk,  butter,  and  cocoa  butter. 

Tripalmitin — C3H5(O.Ci6H3iO)3 — 806 — exists  in  most  animal  and 
vegetable  fats,  notably  in  palm  oil.  It  may  also  be  obtained  by  heat- 
ing glycerol  with  8  to  10  times  its  weight  of  palmitic  acid  for  8  hours 
at  250°  (482°  F.).  It  forms  crystalline  plates,  very  sparingly  soluble 
in  alcohol,  even  when  boiling;  very  soluble  in  ether.  It  fuses  at  50° 
(122°  F.),  and  solidifies  again  at  46°  (114.8°  F.). 

Trimargarin  —  C3H5(O.Ci7H33O)3 — 848— has  probably  been  ob- 
tained artificially  as  a  crystalline  solid,  fusible  at  60°  (140°  F.),  so- 
lidifiable  at  52°  (125.6°  F.).  The  substance  formerly  described  under 
this  name  as  a  constituent  of  animal  fats  is  a  mixture  of  tripalmitin 
and  tristearin. 

Tristearin — C3H5(O.Ci8H35O)3 — 890 — is  the  most  abundant  con- 
stituent of  the  solid  fatty  substances.  It  is  prepared  in  large 
quantities  as  an  industrial  product  in  the  manufacture  of  stearin 
candles,  etc.,  but  is  obtained  free  from  tripalmitin  only  with  great 
difficulty. 

In  as  pure  a  form  as  readily  obtainable,  it  forms  a  hard,  brittle, 
crystalline  mass;  fusible  at  68°  (154.4°  F.),  solidifiable  at  61°  (141.8° 
F.);  soluble  in  boiling  alcohol,  almost  insoluble  in  cold  alcohol, 
readily  soluble  in  ether. 


318  MANUAL    OP    CHEMISTRY 


Triolein—  CaHsfO.CigHsaOh  —  884  —  exists  in  varying  quantity  in 
all  fats,  and  is  the  predominant  constituent  of  those  which  are  liquid 
at  ordinary  temperatures.  It  may  be  obtained  from  animal  fats  by 
boiling  with  alcohol,  filtering  the  solution,  decanting  after  twenty  - 
four  hours'  standing;  freezing  at  0°  (32°  F.),  and  expressing. 

It  is  a  colorless,  odorless,  tasteless  oil;  soluble  in  alcohol  and 
ether,  insoluble  in  water;  sp.  gr.  0.92. 

The  Neutral  Oils  and  Fats  are  mixtures  in  varying  proportions 
of  the  triglycerids  of  the  acids  of  the  acetic  and  acrylic  series,  princi- 
pally tripalmitin,  tristearin,  and  triolein.  The  first  two  of  these  are 
solid  at  the  ordinary  temperature  and  the  last  liquid.  In  the  oils  the 
last  predominates,  in  the  fats  the  former.  In  the  cold  the  oils  be- 
come solid  (fats),  and,  on  heating,  the  fats  become  oils.  The  fats 
and  oils  are  usually  odorless,  white  or  yellow,  unctuous  to  the  touch, 
and  produce  a  translucent  stain  upon  paper.  They  are  insoluble  in 
and  lighter  than  water,  readily  soluble  in  ether,  petroleum  ether,  ben- 
zene, and  many  other  organic  solvents.  Although  the  oils  do  not 
mix  with  water,  and  promptly  rise  to  its  surface  after  having  been 
agitated  with  it,  an  oil  may  remain  suspended  for  a  long  time;  sus- 
pended in  very  minute  globules  in  an  aqueous  liquid,  if  bile,  pan- 
creatin,  albumen,  or  other  emulsifying  agents  be  present.  Such  a 
mixture,  sometimes  practically  permanent,  is  called  an  emulsion. 

Like  other  esters  the  fats  and  oils  are  hydrolyzed  or  saponified 
when  heated  with  steam  or  with  a  caustic  alkali.  The  alcohol, 
glycerol,  is  liberated,  and,  if  steam  be  used,  the  fatty  acid  also;  while 
if  an  alkali  be  used  a  soap  is  formed,  which  is  a  salt  of  the  fatty  acid. 
The  sodium  soaps  are  hard,  those  of  potassium  soft.  Castile  soap  is 
a  sodium  soap,  made  from  olive  oil.  Yellow  soap  is  made  from  tal- 
low or  other  animal  fat,  and  contains  about  one  -third  of  its  weight 
of  rosin.  Lead  plaster  is  lead  soap. 

The  fixed  oils  are  so  called  to  distinguish  them  from  the  volatile 
oils,  more  properly  called  essences,  which  are  also  unctuous  to  the 
touch,  and  render  paper  translucent,  but  which  are  hydrocarbons, 
not  esters. 

The  vegetable  oils  form  three  classes  :  (1)  The  non-drying,  or 
greasy  oils,  which  remain  liquid  and  greasy  on  exposure  to  air. 
Olive  oil  and  peanut  oil  are  representatives  of  this  class.  (2)  Drying 
oils,  which  dry  and  become  hard  when  exposed  to  air.  These  oils, 
which  contain  linoleic  acid  (p.  375),  are  used  in  making  paints. 
Linseed,  hemp,  poppy,  and  sunflower  oils  are  drying  oils.  (3)  Semi- 
drying  oils  are  intermediate  between  the  other  two  classes,  and  are 
more  or  less  drying.  In  this  class  are  cottonseed,  sesame,  rape  seed, 
and  castor  oils.  The  animal  oils,  used  for  dressing  leather,  as  lubri- 
cants and  for  illumination,  are  fish  oils,  whale,  and  porpoise  oil, 


ESTERS  OF  POLYHYDEIC  ALCOHOLS,  ETC.        319 

neat's  foot  oil,  lard  oil,  and  tallow  oil.  Cod  liver  oil  contains,  be- 
sides the  glycerids  of  oleic,  rayristic,  palmitic,  and  stearic  acids, 
small  quantities  of  those  of  butyric  and  acetic  acids.  It  also  contains 
certain  biliary  principles,  a  phosphorized  fat,  traces  of  iodin  and 
bromin,  probably  in  organic  combination,  a  peculiar  fatty  acid  called 
gadinic  acid,  a  brown  substance  called  gadinin,  and  two  alkaloidal 
bodies  :  asellin,  C25H32N4,  and  morrhuin,  CigH^Na.  Sperm  oil  is 
not  a  true  oil,  but  a  liquid  wax;  it  contains  no  glycerids,  but  consists 
mainly  of  esters  of  the  higher  monoatomic  alcohols. 

Lecithins  —  Phosphorized  Fats. — These  substances  are  widely 
distributed  in  animal  and  vegetable  tissues  and  fluids,  and  are  par- 
ticularly abundant  in  the  yolks  of  eggs,  brain,  and  nerve  tissue, 
semen,  and  blood -corpuscles  and  plasma,  where  they  probably  serve 
as  material  for  the  formation  of  the  more  complex  phosphorized 
bodies  such  as  protagon  and  the  nucleins.  The  lecithins  are  colorless 
or  yellowish,  imperfectly  crystalline  solids,  of  a  waxy  consistency, 
and  very  hygroscopic.  They  do  not  dissolve  in  water,  but  swell  up 
in  it  like  starch.  They  are  soluble  in  chloroform,  in  benzene,  and  in 
hot  alcohol  and  hot  ether.  From  alcoholic  solutions  they  crystallize 
in  fine  needles.  When  heated  with  baryta  water  or  with  acids  they 
are  decomposed  into  glycero- phosphoric  acid  (p.  317),  cholin  (p.  330), 
and  a  fatty  acid,  usually  palmitic  or  stearic.  The  lecithins  are  there- 
fore derivatives  of  glycero -phosphoric  acid,  in  which  the  two  remain- 
ing hydroxyls  of  the  glycerol  are  replaced  by  fatty  acid  residues,  and 
one  of  the  two  remaining  basic  hydrogen  atoms  of  the  phosphoric  acid 
is  replaced  by  the  basic  radical  of  cholin,  which  is  a  quarternary  am- 
monium : 


/O.N.CH2.CH2.OH 
O:P— OH 

\O.CH2.CH(Ci8H3502).CH2(C16H3i02) 
Stearyl-palmityl  lecithin. 

From  the  above  formula  it  will  be  seen  that  the  lecithins  may 
unite  with  acids,  through  the  remaining  OH  of  the  cholin,  or  with 
bases,  through  the  remaining  basic  H  of  the  phosphoric  acid,  to  form 
salts.  The  lecithins  differ  from  each  other  in  the  nature  of  the  fatty 
acids  entering  into  their  composition.  Distearyl- ,  dioleyl-  and  stearyl- 
palmityl  lecithins  are  known. 

ESTERS  OF  POLYHYDRIC  ALCOHOLS,  AND  OF  ALDO-  AND  KETO- 

ALCOHOLS 

The  superior  alcohols  form  esters  with  the  pure  acids  in  the  same 
manner  as  does  glycerol.  Tetra-acetyl  erythrol:  €4^(02^02)4, 
Tetra-nitro  erythrol:  C4H6(NO3)4;  Hexacetyl  mannitol:  CeHs- 


320  MANUAL    OF    CHEMISTRY 


and  Hexanitro  mannitol  :  CeHgCNOaJe  are  examples  of 
such  compounds. 

The  hexoses  also  form  esters  with  mineral  and  organic  acids. 
Thus  diacetic  glucose,  CeHioCMCC^.CHsh,  is  formed  as  a  very  bitter 
solid,  very  soluble  in  water,  alcohol  and  ether,  by  the  action  of  acetic 
anhydrid  upon  glucose.  This,  heated  with  acetic  anhydrid  at  140°, 
furnishes  triacetic  glucose,  CeHgC^CC^.CHah,  which,  in  turn,  is 
converted  into  tetracetic  glucose,  CeHsCMCC^.CHs)^  by  the  action 
of  acetic  anhydrid  at  160°. 

Acetochlorhydrose—  CHO.(CH.C02.CH3)4.CH2C1—  is  formed  by 
heating  d-  glucose  with  acetyl  chlorid:  C6Hi2O6-|-4C2H3O.Cl=Ci4  Hi9- 
OgCl-fSHCl-hlkO.  It  is  a  colorless,  odorless,  bitter  semi-solid,  insol- 
uble in  water,  soluble  in  alcohol  and  in  ether.  It  reduces  Fehling's 
solution.  Heated  in  presence  of  water,  it  regenerates  glucose. 
Heated  with  potassium  phenate,  it  forms  glucosyl  phenate,  or  phenol- 
glucosid,  OHO.  (CH.CO2.CH3)4.CH2C1  +  C6H5.O.K.+  4H2O=CHO.- 
(CHOH)4CH2.O.C6H5+KC1+4CH3.COOH,  the  simplest  of  the  glu- 
cosids,  substances  frequently  referred  to  as  esters  of  glucose,  but 
which  are  more  properly  composite  ethers  containing  glucose  and 
phenolic  residues,  united  by  oxygen  (p.  409). 

ESTEES    OF    OXY  ACIDS  —  LACTIDS    AND    LACTONES. 

The  oxyacids  not  only  form  esters  with  the  alcohols  in  the  same 
manner  as  the  pure  acids,  but,  being  themselves  both  alcohol  and 
acid,  they  produce  cyclic  esters,  in  the  formation  of  which  they  play 
the  part  of  alcohol  as  well  as  that  of  acid.  The  lactids  are  formed  by 
the  interaction  of  two  oxyacid  molecules,  each  performing  the  functions 
of  both  alcohol  and  acid.  The  lactones,  which  are  formed  only  by  the 
7  and  higher  oxyacids,  are  produced  from  a  single  molecule  of  the  acid, 
whose  carboxyl  and  alcoholic  groups  interact  with  each  other.  The 
following  formulae  will  indicate  the  genesis  of  the  lactids  and  lactones  : 

CH2OH  COOH 

I  +       I 

COOH  CH2OH 


CH2.COO 

COOH 

cooi 

1        ! 

1 

| 

COO.CH2 

a  CH2 

1 

a  CH2 

1 

ft  CH2 

ft  CH2 

1 

1 

y  CH2OH 

7  CHo 

Glycollic  acid.  Glycollid  7,-Oxybutyric    7,-Butyrolactone 

(Lactid.)  acid.  (Lactone.) 

The  7  lactones  are  formed  from  the  7  monohalogen  acids  :    (1)  by 

distillation  :  COOH.CH2.CH2.CH2Cl=COO.CH2.CH2.CH2-f  HC1;    (2) 
by  boiling    with    H2O,    KHO    or    K2CO3:COOH.CH2.CH2.CH2C1+ 

KHO=H2O+KC1+COO.CH2.CH2.CH2. 


SULFUR    DERIVATIVES    OF    THE    PARAFFINS  321 

By  reduction  the  higher  lactones  yield  aldo-hexoses.  Thusd-glu- 
cose  is  produced  by  the  reduction  of  the  lactone  of  d-gluconic  acid  : 

COO.(CHOH)4.CH2-f-H2=CHO.(CHOH)4.CH2OH.  The  higher  oxy- 
carboxylic  acids  readily  lose  water  and  are  converted  into  lactones 
(p.  294). 

SULFUR   DERIVATIVES   OF   THE   PARAFFINS 

As  the  mineral  sulfids  and  sulfhydrates  correspond  to  the  oxids 
and  hydoxids,  so  there  exist  thioethers  and  thioalcohols,  which  are 
the  counterparts  of  the  simple  ethers  and  of  the  alcohols,  as  well 
as  thioaldehydes,  thioketones  and  thioacids.  Moreover,  as  sulfur 
may  be  quadrivalent  or  hexavalent,  as  well  as  bivalent,  there  exist 
other  important  compounds,  the  sulfoxids,  sulfones  and  sulfonic 
acids,  which  have  no  oxygen  analogues. 

The  following  formulae  will  serve  to  illustrate  the  relations  of 
the  oxygen  and  thio  compounds: 

CH2OH               /CH2.CH3                COOH  /O.CH2.CH3 

O  CH3.CH 

CH3                     \CH2.CH3                CH3  \O.CH2.CH3 

Ethylic  alcohol.             Ethyl  oxid.  Acetic  acid,  Acetal. 

CH2SH  /CH2.CH3  COSH  /S.CH2.CH3 

S  I  CH3.CH 

CH3  \CH2.CH3  CH3  \S.CH2.CH3 

Ethylic  thioalcohol.         Ethyl  sulfid.  Thioacetic  acid.  Mercaptal. 

Thioethers,  or  Sulfids  — are  produced  by  processes  corresponding 
to  those  by  which  the  ethers  are  formed:  (1)  by  distilling  salts  of 
ethyl -sulf uric  acids  with  potassium  sulfid;  (2)  by  the  action  of  the 
paraffin  haloids  upon  potassium  sulfid;  and  by  other  methods.  They 
are  colorless  liquids,  having  very  disagreeable  odors. 

Thioalcohols — Mercaptans — are  formed  by  the  action  of  the  paraffin 
haloids  upon  potassium  sulfhydrate :  C2H5Cl-hKHS=C2H5.SH-hKCl; 
also  by  distilling  the  salts  of  acid  sulfuric  esters  with  potassium  sulf- 
hydrate: SO4.C2H5.K+KHS==C2H5.SH+K2S04.  The  name  mercap- 
tan  (mercurium  captans)  is  derived  from  the  property  of  these  com- 
pounds of  forming  a  sparingly  soluble,  crystalline  compound  with 
mercuric  oxid  ^Hs.ShHg.  Such  metallic  compounds  of  mercaptan 
are  called  mercaptids. 

Ethyl  mercaptan  —  Ethyl  sulfhydrate — Thioalcohol — CH3.CH2.- 
SH  —  is  prepared  industrially,  as  the  first  step  in  the  formation 
of  sulfonal,  by  the  first  of  the  general  methods  given  above.  It  is 
a  colorless  liquid,  sp.  gr.  0.3325,  boils  at  36.2°  (97.2°  F.),  has  an 
intensely  disagreeable  odor,  burns  with  a  blue  flame,  is  neutral  in 
21 


322  MANUAL    OF    CHEMISTRY 

reaction,  sparingly  soluble  in  water,  soluble  in  alcohol  and  in  ether, 
dissolves  I,  S  and  P.  Potassium  and  sodium  act  upon  mercaptan  as 
they  do  upon  alcohol,  replacing  the  extra-radical  hydrogen  to  produce 
mercaptids,  or  thioethylates,  corresponding  to  the  ethylates. 

There  also  exist  mono-  and  di-thioglycols,  corresponding  to  the 
dihydric  alcohols  (p.  251).  One  of  these,  monothioethylene  glycol: 
C2H4.OH.SH,  yields  isethionic  acid  on  oxidation  (see  below). 

Sulfoxids  and  Sulfones  —  are  products  of  oxidation  of  the  sulfids, 
in  which  the  sulfur  is  quadrivalent  or  hexavalent: 


C2H5\q  C2H5\  q  _  0  CaHsXo./O 

C2H5/S  C2H5/b  C2H5/b\0 

Ethyl  sulfid.  Ethyl  sulfoxid.  Ethyl  sulfone. 

Other  products  of  oxidation  of  thio-  compounds,  containing  the 
group  (802)"  attached  to  a  hydrocarbon  group,  are  also  called 
sulfones  (see  below). 

Sulfonic  Acids  —  are  acids  containing  the  group  (028.  OH)'  at- 
tached to  a  hydrocarbon  group.  The  sulfonic  acids  of  this  series 
are  formed  by  oxidation  of  the  mercaptans;  by  the  action  of  the 
paraffin  iodids  upon  the  alkaline  sulfites  ;  or  by  the  action  of  sulf  uric 
acid  upon  alcohols,  ethers,  etc.  (see  Aromatic  Sulfonic  Acids).  They 
may  be  considered  as  being  the  acid  esters  of  the  unsymmetrical 
sulfurous  acid. 

The  thioglycols  on  oxidation  also  yield  sulfonic  acids.  Isethionic 
acid,  C2H4.OH.SOsH,  mentioned  above,  is  a  thick  liquid,  whose 
amido  derivative  is  taurin  (see  Am  ido-  acids). 

In  the  thiosulfonic  acids,  which  only  exist  in  their  salts  and 
esters,  the  oxygen  in  the  hydroxyl  of  the  sulfonic  acids  is  replaced 
by  sulfur. 

Sulfinic  acids  bear  the  same  relation  to  hydrosulfurous  acid 
that  the  sulfonic  acids  do  to  the  unsymmetrical  sulfurous  acid: 


/H  0\g/C2H5  0\S/C2H5  0-S/H  o- 

0./\OH  0./b\OH  (Vb\SH  b\OH  U~     \OH 

Unsymmetrical  Ethyl  sulfonic  Ethyl  thiosulfonic  Hydrosulfurous  Ethyl  sulfinic 

sulfurous  acid.  acid.  acid.  acid.  acid. 

Thioaldehydes  and  their  Sulfones.  —  The  simple  thioaldehydes 
are  not  known,  owing  to  the  tendency  to  polymerize  which  they  pos- 
sess to  a  still  more  marked  degree  than  the  aldehydes  (p.  257).  The 
trithioaldehydes  and  their  sulfones  are  known  as  odorless,  colorless 
solids.  The  relations  of  these  compounds  are  shown  by  the  following 
formulae  : 


n  —  r  Q-P  o-rTT  Q2.\PTT  n  Q/CH2.SO2\  PTT 

"\H  D\H  °\CH2.0/CH2  S\CH2.S/CH2  °2b\CH2.S02/CH2 

Formic  Thloformic             Triform-  Trithioform-                       Trimethylene 

aldehyde.  aldehyde.            aldehyde.  aldehyde.                            trisulfone. 


SULFUR    DERIVATIVES    OF    THE    PARAFFINS  323 

Thioacetals  —  Mercaptals  —  are  produced  by  the  action  of  paraffin 
iodids  upon  alkali  mercaptids,  or  by  the  action  of  HC1  upon  a  mix- 
ture of  aldehyde  and  niercaptan.  By  oxidation  they  yield  sulfones, 
whose  methylene  hydrogen  may  be  replaced  by  alkyl  groups  : 

H\r/O.C2H5    H\r/S.C2H5    H\r/S02.C2H5        H\r/SO2.C2H5 

H/U\O.C2H5    H/^\S.C2H6    H/^\SO2.C2H5    CH3/  ^ 


Methylene  diethyl  ether         Methylene  Methylene  diethyl  Ethidene  diethyl 

(Acetal).  mercaptal.  sulfone.  sulfone. 

Thioketones  —  Mercaptols,  and  their  Sulfones  —  are  produced  by 
the  action  of  HC1  upon  a  mixture  of  ketone  and  mercaptan  ;  or  upon 
an  alkyl  thiosulfate.  In  these  compounds  both  of  the  hydrogen  atoms 
of  the  methylene  group  are  replaced  by  alkyl  groups.  Oxidizing 
agents  convert  them  into  sulfones,  among  which  are  sulfonal  and  its 
congeners. 

Ethyl  Mercaptol—  (CH3)2:C:(SC2H5)2—  is  obtained  as  one  of  the 
steps  in  the  manufacture  of  sulfonal,  by  the  action  of  dry  HC1  upon 
a  mixture  of  acetone  and  sodium  ethylthiosulfate,  C2H5S.SO3Na.  It 
is  a  mobile  liquid,  of  not  unpleasant  odor,  boiling  at  190°  (374°  F.). 

Sulfonal—  Acetone  Diethyl  Sulfone—  (CH3)2:C:  (SO2C2H5)2—  is 
obtained  by  oxidizing  ethyl  mercaptol  by  potassium  permanganate.  It 
crystallizes  in  thick,  colorless  prisms,  difficultly  soluble  in  cold  water 
or  alcohol,  readily  soluble  in  hot  water  or  alcohol,  and  in  ether,  ben- 
zene, and  chloroform.  It  fuses  at  126°  (226.8°  F.)  and  boils  at  300° 
(572°  F.),  suffering  partial  decomposition. 

Sulfonal  contains  two  ethyl  groups,  trional  contains  three,  and 
tetronal  four.  Their  hypnotic  power  increases  with  the  number  of 
ethyl  groups  which  they  contain.  Other  "sulfonals"  are  obtainable 
from  the  corresponding  mercaptols  by  methods  similar  to  the  above. 
Among  these  is  acetone  dimethyl  sulfone,  which  contains  no  ethyl 
group,  and  has  no  hypnotic  action.  The  relations  of  these  com- 
pounds is  shown  by  the  following  formulae  : 

CH3\P/S02.C2H5    CH3\P/S02.C2H5  C2H5\p/SO2.C2H5  CH3\P  /SO2.CH3 
CH3/^\S02.C2H5  C2H5/^\S02.C2H5  C2H5/  ^  \SO2.C2H5  CH3/^  \SO2.CH3 


Sulfonal.  Trional.  Tetronal.  Acetone  dimethyl 

sulfone. 

Ichthyol.  —  is  the  Na  salt  of  a  complex  sulfonic  acid,  having  the 
empirical  formula  C28H3eS3O6Na2,  obtained  by  the  distillation  and 
purification  of  an  ozocerite  (a  mineral  pitch).  It  is  a  dark  brown, 
pitchlike  mass,  having  a  disagreeable  odor,  soluble  in  water  and  in 
glycerol. 

Thioacids  and  their  Thioanhydrids.  —  In  the  thioacids  of  the 
acetic  series  the  sulfur  is  substituted  for  the  oxygen  in  the  hydroxyl. 
Thioacetic  acid,  CH3.CO.SH,  is  formed  by  the  action  of  phosphorus 
pentasulfid  upon  acetic  acid. 


324  MANUAL    OP    CHEMISTRY 

Thioacids   derivable  from   Carbonic  acid. —  Five  of  these  com- 
pounds are  known  in  their  derivatives,  although  the  free  acids  are 
unknown   or  very  unstable.      The  formulae  of   the  free  acids   are: 
pn/SH   r,n/SH  pQ/OH    pQ/SH          ,   pq/SH 
LO\OH»  ^°\SH>  ^b\OH»  °k\OH>  and  Ob\SH 

Thio  derivatives  of  glycollic  and  of  lactic  acid  are  also  known. 
Carbon  Disulfid  —  €82 — bears  the  same  relation  to  sulfothiocar- 

bonic  acid,  CS^OH»  an<^  *°  trithiocarbonic  acid,  CS\^SH,  that  carbon 
dioxid  bears  to  carbonic  acid  (p.  302).  It  is  prepared  by  passing 
vapor  of  S  over  C  heated  to  redness,  is  partly  purified  by  rectifica- 
tion, and  obtained  pure  by  redistillation  over  mercuric  chlorid. 

It  is  a  colorless  liquid.  When  pure  it  has  a  peculiar,  but  not 
disagreeable  odor,  the  nauseating  odor  of  the  commercial  product 
being  due  to  the  presence  of  another  sulfurated  body;  boils  at  47° 
(116.6°  F.);  sp.  gr.  1.293;  very  volatile.  Its  rapid  evaporation  in 
vacuo  produces  a  cold  of  — 60°  ( — 76°  F.).  It  does  not  mix  with 
H20.  It  refracts  light  strongly. 

It  is  highly  inflammable,  and  burns  with  a  bluish  flame,  giving 
off  C02  and  862;  its  vapor  forms  highly  explosive  mixtures  with 
air,  which  detonate  on  contact  with  a  glass  rod  heated  to  250° 
(482°  F.).  Its  vapor  forms  a  mixture  with  nitrogen  dioxid,  which, 
when  ignited,  burns  with  a  brilliant  flame,  rich  in  actinic  rays. 

A  substance  also  exists,  intermediate  in  composition  between  C02 
and  €82,  known  as  carbon  oxysulfid,  CSO,  which  is  an  inflammable, 
colorless  gas,  obtained  by  decomposing  potassium  thiocyanate  with 
dilute  H2SO4. 

Toxicology. —  Cases  of  acute  poisoning  by  €82  have  hitherto 
only  been  observed  in  animals.  Its  action  is  very  similar  to  that 
of  chloroform. 

Workmen  engaged  in  the  manufacture  of  €82,  and  in  the  vul- 
canization of  rubber,  as  well  as  others  exposed  to  the  vapor  of  the 
disulfid,  are  subject  to  a  form  of  chronic  poisoning  which  may  be 
divided  into  two  stages.  The  first,  or  stage  of  excitation,  is  marked 
by  headache,  vertigo,  a  disagreeable  taste,  and  cramps  in  the  legs.  The 
patient  talks,  laughs,  sings,  and  weeps  immoderately,  and  sometimes 
becomes  violently  delirious.  In  the  second  stage  the  patient  becomes 
sad  and  sleepy,  sensibility  diminishes,  sometimes  to  the  extent  of 
complete  anaesthesia,  especially  of  the  lower  extremities,  the  head- 
ache becomes  more  intense,  the  appetite  is  greatly  impaired,  and 
there  is  general  weakness  of  the  limbs,  which  terminates  in 
paralysis. 

The  only  remedy  which  has  been  suggested  is  thorough  ventila- 
tion of  the  workshops,  and  abandonment  of  the  trade  at  the  first 
appearance  of  the  symptoms. 


ORGANO-  METALLIC    COMPOUNDS  325 

ORGANO-METALLIC    COMPOUNDS. 

These  are  compounds  of  the  alcoholic  radicals  with  metals.  They 
are  usually  obtained  by  the  action  of  the  alkyl  iodid  upon  the  metallic 
element,  in  an  atmosphere  of  H  or  of  CO2.  Zinc  methid  and  ethid 
are  valuable  synthetic  reagents,  as  in  the  formation  of  hydrocarbons, 
alcohols,  and  ketones. 

Zinc  Ethid — Zinc  ethyl — ^HshZn — is  obtained  by  heating  at 
130°  (266°  F.),  in  a  sealed  tube,  a  mixture  of  zinc  amalgam  and  ethyl 
iodid,  and  distilling  the  product  without  contact  of  air. 

It  is  a  colorless  liquid,  sp.  gr.  1.182,  boils  at  118°  (244.4°  F.). 
On  contact  of  air  it  ignites,  burns  with  a  flame  bordered  with  green, 
and  gives  off  dense  clouds  of  zinc  oxid.  On  contact  with  water  it  is 
decomposed  into  zinc  hydroxid  and  ethane. 

NITROGEN   DERIVATIVES  OF  THE  PARAFFINS. 

NITROPARAPPINS. 

The  univalent  group  (NO2)  is  designated  by  the  syllable  nitro  in 
the  names  of  compounds  containing  it. 

The  mononitroparaffins — isomeric  with  the  nitrous  esters  (p.  311) , 
are  derived  from  the  paraffins  by  the  substitution  of  N02  for  an  atom 
of  hydrogen,  and  are  distinguished  as  primary,  secondary,  and  ter- 
tiary, in  the  same  manner  as  the  corresponding  alcohols  (p.  240) 
according  as  the  NO2  is  united  to  CH2,CH,  or  C.  They  are  formed 
by  the  action  of  the  alkyl  iodids  upon  silver  nitrite :  CHaH- AgN02= 
AgI+CH3N02. 

They  are  not  acted  upon  by  caustic  potash,  which  readily  decom- 
poses the  isomeric  nitrous  esters  :  N02.C2H5+KHO  =  KNO2+C2- 
H5.HO. 

Nascent  hydrogen  converts  them  first  into  hydroxylamin  com- 
pounds (p.  105) :  CH3.NO2+2H2=CH3.NH.OH+H2O,  which  are  in 
turn  further  reduced  to  monamins,  or  amidoparaffins :  CH3.NH.OH-|- 
H2=NH2.CH3-hH20. 

Nitrous   acid   converts  the   primary   nitroparaffins   into   nitrolic 

acids,  as  ethyl-nitrolic  acid,  CH3.C^oH'  tne  liquid  assuming  a  red 
color.  The  same  agent  converts  the  secondary  nitroparaffins  into 
pseudonitrols,  as  propyl  pseudonitrol,  CH3/C\NO2>  ^e  liquid  be- 
coming blue.  Upon  the  tertiary  nitroparaffins  nitrous  acid  has  no 
action.  These  reactions  are  utilized  to  distinguish  primary,  secon- 
dary, and  tertiary  alcohols  from  each  other. 


326  MANUAL    OF    CHEMISTRY 

AMINS    AND    AMMONIUM    DERIVATIVES. 

The  amins  are  compounds  derived  from  ammonia  by  the  substi- 
tution of  hydrocarbon  (non-acid)  radicals  for  a  part  or  all  of  its 
hydrogen. 

They  are  classified  into  monamins,  derived  from  a  single  molecule 
of  ammonia,  diamins,  derived  from  two  such  molecules,  and  triamins, 
derived  from  three. 


MONAMINS    AND    THEIR    DERIVATIVES. 

The  monamins  are  primary,  secondary,  or  tertiary,  as  one,  two, 
or  three  of  the  hydrogen  atoms  of  ammonia  have  been  replaced. 
They  are  also  distinguished  as  amin,  imin,  and  nitril  bases.  When, 
in  secondary  or  tertiary  amins,  the  substituted  radicals  are  alike  the 
amins  are  designated  as  simple,  when  the  radicals  are  different  the 
amins  are  mixed.  The  primary  monamins,  containing  the  group 
NH2,  are  amido-paraffins  ;  while  the  secondary,  containing  the  group 
NH,  are  imido-paraffins.  The  monamins  have  the  algebraic  formula, 


The  monamins  are  sometimes  called  compound  ammonias,  from 
their  resemblance  to  ammonia  in  their  chemical  properties,  as  well  as 
from  their  origin.  They  combine  with  water  to  produce  quarternary 
ammonium  hydroxids,  similar  in  constitution,  alkalinity,  and  ba- 
sicity to  ammonium  hydroxid;  and  with  acids,  without  elimination  of 
hydrogen,  to  form  salts,  similar  to  the  ammoniacal  salts. 

The  aliphatic  monamins  are  the  most  simply  constituted  of  a  great 
variety  of  nitrogen  derivatives,  including  the  amids  (p.  345),  such  as 
urea,  and  the  vegetable  alkaloids  (p.  469),  which  have  this  in  com- 
mon with  the  amins,  that  they  are  basic  in  character,  and,  in  com- 
bining with  acids,  form  salts  in  the  same  manner  as  ammonia  does, 
i.  e.,  by  change  of  the  nitrogen  valence  from  three  to  five,  and,  con- 
sequently, without  elimimination  of  hydrogen;  thus: 

/H                     /H  /H  /CH3 

N—  H            H2=N—  H  N—  H  H2=N—  CH3 

\H                       \C2H302  \CH3  \C1 

Ammonia.                  Ammonium  Monomethyl-  Dimethylammo- 

acetate.  amin.  nium  ohlorid. 


NH2  NH2 

CO 


CO 


CH2 

/\ 

TT  /~i         r<Ti 

±12U            L/X12 

1            1 
H2C        CH2 
\/ 

N 

H 

CH2 

H2C        CH2 
1          I 
H2C        CH2 
\/ 

N 

/s 

Cl    H2 

NH2  N— N03 


Urea.  Urea  nitrate  ?  Piperidin.  Piperidin  hydrochlorid. 


NITROGEN    DERIVATIVES    OF    THE    PARAFFINS  327 

The  naming  of  these  compounds  has  been  the  subject  of  much 
discussion.  As  the  substances  formed  by  the  union  of  ammonia  with 
acids  are  regarded  as  salts  of  ammonium,  not  of  ammonia,  so  these 
compounds  are  not  salts  of  urea,  piperidin,  morphin,  etc.,  but  salts 
of  hypothetical  bases,  containing  a  quinquivalent  nitrogen  atom, 
which  in  the  free  base  is  trivalent.  The  names:  ureium  nitrate,  piper- 
idium  chlorid,  morpMum  sulfate,  etc.,  are  therefore  the  analogues  of 
ammonium  acetate  and  dimethylammonium  chlorid.  For  the  c^lorin, 
bromin,  and  iodin  compounds  the  names:  piperidin  hydrochlorid, 
morphin  hydrobromid,  quinin  hydroiodid,  etc.,  may  be  conveniently 
retained,  they  being  regarded  as  the  free  bases,  plus  hydrogen,  plus 
the  halogen. 

The  alkalinity  and  solubility  in  water  of  the  primary  monamins 
are  greater  than  those  of  the  secondary,  and  those  of  the  secondary 
greater  than  those  of  the  tertiary.  Their  chlorids  form  sparingly 
soluble  compounds  with  platinic  chlorid.  The  following  formulae  in- 
dicate their  constitution  : 


(C2H5)4N.C1 

Tetrethyl 

ammonium 

chlorid. 

The  primary  monamins  are  formed:  (1)  by  distilling  the  iso- 
cyanic  esters  with  caustic  potash:  CO:N.C2H5H-2KHO=NH2.C2H5+ 
€63X2;  (2)  by  heating  the  alkyl  iodids,  or  the  nitric  esters,  with 
alcoholic  ammonia:  C2H5H-NH3=NH2.C2H5+HI,  or  C2H5.N03  + 
NH3=NH2.C2H5+HN03;  (3)  by  the  action  of  nascent  H  in  alcoholic 
solution  upon  the  nitrils  (p.  340) :  CH3.CNH-2H2=NH2.C2H5;  (4)  by 
the  action  of  nascent  H  upon  the  nitroparaffius :  CH3.NO2+3H2=NH2- 
CH3+2H2O;  (5)  from  the  monamids  (p.  345)  of  the  fatty  series 
monamins,  containing  one  atom  of  carbon  less  than  the  amid,  are 
formed  by  the  action  of  bromin  and  potassium  hydroxid.  The  reac- 
tion occurs  in  two  stages.  First  a  bromid  is  produced:  C2H5.CO.- 
NH2+Br2+KHO— C2H5.CO.NHBr+KBr-{-H2O,  which  is  in  turn 
converted  into  the  amin  with  loss  of  the  carbonyl  group:  C2H5.CO.- 
NHBr+3KHO=C2H5.NH2+CO3K2+H20-f-KBr.  (See  also  Ureids, 
p.  350.) 

The  secondary  monamins  are  formed,  as  intermediate  products, 
by  the  action  of  the  alkyl  iodids  upon  the  primary  monamins  in  the 
presence  of  excess  of  ammonia.  The  alkyl -ammonium  iodid  is  first 
produced:  NH2.C2H5+C2H5I=NH(C2H5)2HI,  and  this  reacts  with  the 
ammonia:  NH(C2H5)2HI+NH3=NH(C2H5)2-hNH4l.  The  final  pro- 
ducts of  the  reaction  are  the  tetrammonium  iodids:  N(C2H5)4l. 


/C2H5 
N—  H 
\H 

Ethylamin. 
(Primary). 

/CH3 

N—  C2H5 
\H 

Methyl- 
ethylamin. 
(  Secondary)  . 

/CH3 
N—  CH3 
\CH3 
Trimethyl- 
amin. 
(Tertiary). 

(CH3)4N.OH 

Tetramethyl 
ammonium 
hydroxid. 

328  MANUAL    OF    CHEMISTRY 

The  tertiary  amins  are  obtained  by  the  dry  distillation  of  the 
quarternary  ammonium  hydroxids,  iodids,  or  chlorids:  N(  €2115)41  = 
N^Hsh-f^HsI;  or  by  heating  the  primary  or  secondary  amius  with 
excess  of  potassium  -alkyl  sulfate:  NH(CHs)i+CH3.K.S04=N(CHs)*- 
+KHS04. 

The  primary  and  secondary  amins  react  with  the  esters  to  form 
alcohols  and  primary  or  secondary  amids  (p.  346).  Thus  methyl- 
amin,and  methyl  acetate  produce  ethylic  alcohol  and  acetamid:  NH2- 


Nitrous  acid  eliminates  the  nitrogen  from  primary  amins,  with 
formation  of  alcohols,  which  may  be  primary,  secondary  or  tertiary: 
NH2.C2H5+HNO2=CH20H.CH3+N2+H2O.  Nitrous  acid  converts 
the  secondary  amins  into  nitroso-amins,  compounds  in  which  an 
atom  of  hydrogen  is  replaced  by  (NO),  the  "nitroso"  group:  NH- 


The  primary  monamins,  when  warmed  with  chloroform  and  alco- 
holic potash,  yield  carbylamins,  isocyanids,  or  isonitrils  (p.  340)  : 
NH2.C2H5+CHCl3+3KHO—  CN.C2H5+3KC1  +  3H20.  (See  Chloro- 
form, test  1,  p.  235.) 

When  etheral  solutions  of  primary  monamins  and  of  carbon  disul- 
fid  are  evaporated,  a  residue  is  obtained  which,  when  heated  in 
aqueous  solution  with  AgNO3,Fe2Cl6,  or  HgC^  forms  a  sulfid  of  the 
metal  and  a  "mustard  oil,"  having  a  pungent  odor.  This  is  Hoff- 
man's test  for  primary  monamins  (see  p.  344). 

Methylamin  —  Methylia  —  NH^CHs)  —  is  a  colorless,  inflammable 
gas;  having  a  fishy,  ammoniacal  odor.  One  volume  of  H2O  dissolves 
1,154  volumes  at  12.5°  (54.  5°  F.).  The  aqueous  solution  possesses 
the  odor  of  the  gas,  and  is  highly  caustic  and  alkaline.  It  neutralizes 
the  acids  with  formation  of  methylammonium  salts  (e.  g.,  NHs- 
(CHsJ.NOs^methylammonium  nitrate),  which  are  for  the  most  part 
crystallizable  and  very  soluble  in  H2O.  Its  chloraurate-  crystallizes  in 
beautiful  golden-yellow  needles,  soluble  in  water,  alcohol,  and  ether. 
Its  chloroplatinate  crystallizes  in  golden  -yellow  scales,  soluble  in 
water,  insoluble  in  alcohol. 

See  Trimethylamin,  below. 

Dimethylamin  —  Dimethylia—  NH(CH3)2  —  is  a  liquid  below  7.2° 
(45°  F.);  has  an  ammoniacal  odor,  and  is  quite  soluble  in  EbO.  It 
constitutes  about  50  per  cent,  of  the  commercial  trimethylamin,  which 
also  contains  5  to  10  per  cent,  of  trimethylamin,  the  remainder  being 
a  mixture  of  monomethylamin,  isobutylamin,  and  propylamin.  Its 
chloroplatinate  forms  long  needles. 

See  Trimethylamin,  below. 

Trimethylamin  —  Trimethylia  —  NfCHaJs  —  59  —  is  formed  by  the 
action  of  methyl  iodid  upon  NHs,  and  as  a  product  of  decomposition 


NITROGEN    DERIVATIVES    OF    THE    PARAFFINS  329 

of  many  organic  substances,  it  being  one  of  the  products  of  the 
action  of  potash  on  many  vegetable  substances,  alkaloids,  etc.  It 
also  occurs  naturally  in  cod  liver  oil,  ergot,  chenopodium,  yeast, 
guano,  human  urine,  the  blood  of  the  calf,  and  many  flowers. 

It  is  an  oily  liquid,  having  a  disagreeable  odor  of  fish;  boils  at 
3.5°  (38.3°  F.);  alkaline;  soluble  in  H2O,  alcohol,  and  ether;  in- 
flammable. It  combines  with  acids  to  form  salts  of  trimethyl- am- 
monium, which  are  crystallizable.  Its  chloroplatinate  crystallizes  in 
octahedra,  insoluble  in  alcohol. 

Trimethylamin  has  long  been  known  to  exist  in  the  pickle  in 
which  herrings  have  been  preserved.  More  recently  it  has  been 
found  to  be  a  product  of  putrefactive  changes  in  fish,  starch -paste, 
brain -tissue,  muscular  tissue,  and  other  protein  substances,  being 
accompanied  by  lesser  quantities  of  monomethylamin,  dimethylamin, 
ethylamiu,  and  diethylamin,  as  well  as  by  other  peculiar  alkaloidal 
bodies.  It  has  also  been  observed  accompanying  more  active  alka- 
loids in  blood -serum,  etc.,  which  have  served  for  the  culture  of  va- 
rious bacilli. 

The  commercial  trimethlamin,  obtained  by  the  dry  distillation  of 
distillery  waste,  contains  5  to  10  per  cent,  of  the  substance  whose 
name  it  bears.  (See  Dimethylamin,  above.)  It  has  frequently  been 
mistaken  by  writers  upon  materia  medica  for  its  isomere  propylamin, 
(C3ln]}N.  which  differs  from  it  in  odor,  and  in  boiling  at  50°  (122° 

F.).  Its  chlorid,  under  the  names  chlorid  of  propylamia,  of  secalia, 
of  secalin,  has  been  used  in  the  treatment  of  gout  and  rheumatism. 

Tetramethyl  Ammonium  Hydroxid— N(CH3)4OH.— This  sub- 
stance, whose  constitution  is  similar  to  that  of  ammonium  hydroxid, 
is  obtained  by  decomposing  the  corresponding  iodid  (CHaJiNI,  formed 
by  the  action  of  methyl  iodid  upon  trimethylamin.  It  is  a  crystalline 
solid;  deliquescent;  very  soluble  in  EbO;  caustic;  not  volatile  with- 
out decomposition.  It  attracts  carbon  dioxid  from  the  air,  and  com- 
bines with  acids  to  form  crystallizable  salts. 

The  iodid  is  said  to  exert  an  action  upon  the  economy  similar  to 
that  of  curare. 

Tetraethylium  Hydroxid  —  N.  (€2115)4  OH —  forms  deliquescent 
needles,  is  strongly  alkaline,  and  is  used  as  a  solvent  for  uric  acid. 


OXYAMINS  (HYDEAMINS),  DIAMINS,  IMINS  AND  DIIMINS. 

The  primary  monamins  may  be  considered  as  being  derived  from 
the  monoatomic  alcohols  by  the  substitution  of  the  amido  group,  NEb, 
for  the  hydroxyl.  From  the  dihydric  alcohols,  the  glycols,  two  classes 
of  amido  compounds  may  be  similarly  derived.  One  of  these,  the 


330  MANUAL    OF    CHEMISTRY 

oxyamins,  or  hydramins,  contain  a  single  amido  group,  and  retain 
an  alcoholic  hydroxyl.  In  the  diamins  both  hydroxyls  are  replaced 
by  amido  groups.  The  oxyamins  are  primary,  secondary  and  tertiary 
in  the  same  manner  as  the  monamins  : 

CH2OH      CH2OH      CH2NH2      CH2(OH).CH2\  CH2(OH).CH2\ 

NH      CH2(OH).CH2—  N 
CH2OH      CH2NH2    CH2NH2      CH2(OH).CH2/  CH2(OH).CH2/ 

Glycol.          Oxyethyl-     Methylene  Dioxyethylene-  Trioxethylene- 

amin.  diamin.  amin.  amin. 

The  diamins  are  primary,  secondary,  and  tertiary,  as  they  contain 
two  groups  NH2,  or  two  groups  NH,  or  two  N  atoms  ; 

/CH2  .CH2\  /CH2  .  CH2\ 

H2N.CH2.CH2.CH2.NH2             HN                       NH  N—  CHo.CH2—  N 

\CH2  .  CH2/  \CH2  .  CH2/ 

Trimethylene  diamin.                          Diethylene  diamin.  Triethylene  diamin. 


The   primary  diamins   have   the  algebraic   formula: 
the  secondary,  N2C«H2«+2;  and  the  tertiary,  N2C«H2«. 

The  secondary  and  tertiary  diamins  are  cyclic  compounds.  (See 
Piperazin.) 

The  oxyamins  are  produced  by  the  action  of  sulfuric  acid  and 
water  upon  the  unsaturated  amins  (p.  377).  Thus  vinylamin  yields 
oxyethylamin:  CH2:  CH.NH2+H2O=CH2OH.CH2NH2. 

The  diamins  are  obtained  by  reduction  of  the  olefin  dicyanids. 
Thus  ethylene  cyanid  yields  tetramethylene  diamin  :  CN.CH2.CH2.CN-|- 
4H2^H2N.CH2.CH2.CH2.CH2.NH2.  Also,  as  hydrobromids,  by  heat- 
ing the  olefin  bromids  with  alcoholic  ammonia,  to  100°  (212°  F.)  under 
pressure  :  Br.CH2.CH2.Br  +  2NH3  =  H3Br  ::  N.CH2.CH2.N  ::  H3Br. 

The  diamins  form  crystalline,  insoluble  compounds  when  shaken 
in  alkaline  solution  with  benzoyl  chlorid,  a  property  which  they  share 
with  polyatomic  alcohols  and  hexoses. 

Cholin  —  Trimethyloxethylammonium  hydroxid  —  Bilineurin  —  Sin- 

CH2OH    OH 

calin  —  I          /         —  occurs  in  hops,  in  fungi,  in  certain  seeds,  in 
CH2.N=(CH3)3 

the  human  placenta,  in  bile  and  in  the  yolks  of  eggs.  It  is  a  con- 
stituent of  the  lecithins  (p.  319).  It  is  formed  synthetically  (as  its 
chlorid)  by  the  union  of  ethylene  chlorhydrin  and  trimethylamin  : 

CH2OH  CH2OH     Cl 

|  4-    N(CH3)3=         I  / 

CH2C1  CH2—  N=(CH3)3 

It  is  produced  during  the  first  twenty  -four  to  forty-eight  hours  of 
putrefaction  of  animal  tissues,  from  the  decomposition  of  the  leci- 
thins, and  diminishes  from  the  third  day,  when  other  ptomains  (neu- 
ridin,  putrescin,  cadaverin)  increase  in  amount.  When  heated,  it 
splits  up  into  glycol  and  trimethylamin.  Nitric  acid  converts  it  into 
muscarin. 


NITROGEN    DERIVATIVES    OF    THE  J>ARAFFINS  331 


It  is  a  thick  syrup,  soluble  in  EbO  and  in  alcohol,  and  strongly 
alkaline  in  reaction.  Even  in  dilute  aqueous  solution  it  prevents  the 
coagulation  of  albumin  and  redissolves  coagulated  albumin  and  fibrin. 
It  is  a  strong  base;  attracts  C02  from  the  air;  forms  with  HC1  a  salt, 
soluble  in  alcohol,  which  crystallizes  in  plates  and  needles,  resembling 
those  of  cholesterin.  Its  chloroplatinate  is  purified  with  difficulty;  its 
chloraurate  readily. 

It  is  poisonous  only  in  large  doses,  in  which  respect  it  differs  from 
neurin  (see  below). 

Amanitin  —  Trimethyloxethylideneammonium    hydroxid  —  Isocholin 

CH3  OH 

/        —  is  an  isomere  of  cholin,  existing  along  with  mus- 

CHOH.N=(CH3)3 

carin  (see  below)  in  Agaricus  muscarius.  It  is  produced  by  methyl- 
ation  of  aldehydeammonia  :  CHa.CHOH.NIk.  By  oxidation  with 

HNOs  it  yields  muscarin. 

CH2OH      OH 

Muscarin  —  I  /  —  is   related  to  cholin,  neurin  and 

CHOH.N=(CH3)3 

amanitin,  from  which  it  may  be  obtained  by  oxidation. 

It  occurs  in  nature  in  Agaricus  muscarius,  and  is  produced  during 
putrefactive  decomposition  of  proteins. 

The  free  base  occurs  in  very  deliquescent,  irregular  crystals,  or,  if 
not  perfectly  dry,  a  colorless,  odorless,  and  tasteless,  but  strongly 
alkaline  syrup;  readily  soluble  in  all  proportions  in  water  and  in 
alcohol;  very  sparingly  soluble  in  chloroform;  insoluble  in  ether.  It 
is  a  more  ..powerful  base  than  ammonium  hydroxid.  When  decom- 
posed it  yields  trimethylamin.  Its  chloroplatinate  crystallizes  in  octa- 
hedra.  Its  chlorid  forms  colorless,  brilliant,  deliquescent  needles. 

When  administered  to  animals,  muscarin  causes  increased  secre- 
tion of  saliva  and  tears;  vomiting;  evacuation  of  faBces,  at  first  solid, 
later  liquid  ;  contraction  of  the  pupils,  almost  to  the  extent  of 
closure;  diminution  of  the  rapidity  of  the  pulse;  interference  with 
respiration  and  locomotion;  gradual  sinking  of  the  heart's  action  and 
respiration;  and  death.  Atropin  prevents  the  action  of  muscarin  and 

diminishes  its  intensity  when  already  established. 

'CH2       OH 
Neurin  —  Trimethylvinylammonium  hydroxid  —  II        /          —  is  a 

CH.N=(CH3)3 

base  resembling  cholin,  for  which  reason  it  is  considered  here,  al- 
though its  proper  place  is  as  a  derivative  of  vinylamin  (q.  v.).  It 
has  been  obtained  from  brain  tissue  and  from  the  suprarenal  capsule, 
probably  as  a  product  of  decomposition  of  protagon.  It  is  produced 
from  cholin  by  boiling  with  baryta  water.  The  same  body  is  one  of 
the  alkaloids  produced  by  the  putrefaction  of  muscular  tissue,  and  is 
endowed  with  poisonous  qualities,  resembling,  but  less  intense  than, 
those  of  muscarin. 


332  MANUAL    OF    CHEMISTRY 

COO 

Betains — are  anhydrids  having  the  general  formula :     \n  \     ,  cor- 

R" —  N^=. 

responding  to  substances  of  mixed  function,  partly  acid  and  partly 

COOH    OH 

quarternary  ammonium :  !  n  /_  ,  in  which  R"  may  be  any  biva- 
lent hydrocarbon  radical,  and  in  which  the  three  remaining  nitrogen 
valences  may  be  satisfied  by  univalent  radicals  or  by  a  trivalent  radi- 
cal. Or  the  arrangement  of  the  valences  may  be  reversed,  as  in 

nicotic  -  methyl  betain :     I 

(C5H4)'"  =  N— CH3. 

Betain — Trimethy I- acetic  betain — Oxyneurin — Oxycholin — Lycin — 

COO 

Trimethyl-glycocoll —  I     \  — was   first   obtained    from   beet- 

CH2-N=(CH3)3 

juice  (Beta  vulgaris).  It  exists  in  beet-sugar  molasses,  in  cotton- 
seed, and  in  malt.  It  is  formed  by  several  synthetic  methods,  e.  g., 
by  the  action  of  methyl  iodid  upon  amido- acetic  acid  (p.  363) : 
COOH  COO 

I  +3CH3I=3HI+  I      \  ;  or  by  the  interaction  of  mono- 

CH2.NH2  CH2— N=(CH3)3. 

COOH  COO 

chloracetic  acid  and  trimethvlamin :  I        +N(CH3)3=  |      \  +HC1. 

CH2C1  CH2— N=(CH3)3 

Betain  crystallizes  in  large,  deliquescent  crystals,  with  one  mole- 
cule of  water  of  crystallization,  very  soluble  in  water  and  in  alcohol. 
It  is  decomposed  by  heat  with  evolution  of  trimethylamin,  a  fact 
which  is  utilized  to  obtain  that  substance  from  beet -molasses.  It  is 
strongly  basic  and  forms  crystalline  salts.  Its  chloraurate  is  crys- 
talline and  very  sparingly  soluble  in  cold  water. 

The  relations  of  the  oxyamin  bases  are  shown  in  the  following 
formulae  : 

CH3  CH2OH  CH3  CH2OH 

CH2  CH2  CHOH  CHOH 

N  N  N  N 

(CH3)3OH  (CH3)3OH  (CH3)3OH  (CH3)3OH 

Ethyl-trimethyl  Cholin.  Isocholin.  Muscarin. 

ammonium  (Amanitin). 

hydroxid 


COH  COOH  COO,  CH2 


CH2 


CH2  CH2                         CH 

.  A 

&  \                        &  \  &                           #  \ 

(CH3)3OH                (CH3)3C1  (CH3)3  (CH3)3OH 

Betain                             Betain  Betain.                          Neurin. 
aldehyde.                     hydrochlomd. 


NITROGEN    DERIVATIVES    OF    THE    PARAFFINS  333 

Among  the  diamins  are  included  several  of  the  alkaloidal  products 
of  putrefaction  known  as  ptomains. 

Ethylenediamin — H2N.(CH2)2.NH2 — is  a  strongly  alkaline  liquid, 
boiling  at  116.5°  (241.7°  F.).  With  acetyl  chlorid  it  forms  diacetyl- 

CH2.NH.CO.CH3 
ethylene  diamin,  I  ,  which  is  decomposed  by  heat  with 

CH2.NH.CO.CH3 
formation  of  a  cyclic  amidin  base  (p.  334),  ethylene-ethenyl  amidin, 

CH2.NH\ 
or  lysidin,     I  ^C.CHa,  a  crystalline  solid,  fusing  at  105°  (221° 

CH2-N 

F.),  which  is  also  prepared  by  heating  ethylenediammonium  chlorid 
with  sodium  acetate,  and  has  been  used  as  a  solvent  for  uric  acid. 

Trimethylenediamin  —  H2N.(CH2)3.NH2  —  is  said  to  have  been 
obtained  from  the  cultures  of  the  comma  bacillus.  It  has  been  ob- 
tained synthetically  by  the  second  method  given  on  p.  330.  It  is  an 
alkaline  liquid,  boiling  at  135°  (275°  F.). 

Tetramethylenediamin — Putrescin  —  H2N.  (CH^.NEk —  is  pro- 
duced, along  with  the  cadaverin,  during  the  putrefaction  of  muscular 
tissue,  internal  organs  of  man  and  animals,  arid  of  fish,  and  in  the 
culture  media  of  the  comma  bacillus  from  three  days  to  four  months. 
The  free  base  is  a  colorless  liquid  (solid  below  27°)  having  a  seminal 
odor,  which  absorbs  C02  from  the  air  and  unites  with  acids  to  form 
crystalline  salts.  It  is  not  activelv  poisonous. 

Pentamethylenediamin —  Cadaverin  —  H^N.  (CKbh  .NH2  —  is  iso- 
meric  with  neuridin  and  is  produced  during  the  later  stages  of  putre- 
faction of  many  animal  tissues,  the  cholin  disappearing  as  this  and 
the  other  diamins  are  formed.  The  free  base  is  a  clear  syrupy  liquid, 
having  a  strong  disagreeable  odor,  resembling  that  of  conim,  boils  at 
175°,  and  fumes  in  air.  It  absorbs  C(>2  rapidly,  with  formation  of  a 
crystalline  carbonate.  Its  salts  are  crystalline.  The  chlorid  on  dry 
distillation  is  decomposed  into  ammonium  chlorid  and  piperidin 
(p.  461). 

Hexamethylenediamin — H2N.(CH2)e.NH2 — is  formed  during  pu- 
trefaction of  muscular  tissue  and  pancreas.  It  is  a  crystalline  solid, 
fusing  at  40°  (104°  F.)  and  boiling  at  195°  (383°  F.). 

Neuridin — C5HuN2 — a  diamin  of  undetermined  constitution,  iso- 
meric  with  cadaverin,  is  produced,  along  with  cholin  (p.  330),  during 
the  earlier  stages  of  putrefaction,  particularly  of  gelatinoid  sub- 
stances, and  increases  in  quantity  as  putrefaction  advances,  while  the 
quantity  of  cholin  diminishes.  The  free  base  is  a  gelatinous  sub- 
stance, having  a  very  marked  seminal  odor,  readily  soluble  in 
water,  insoluble  in  alcohol  and  in  ether.  Its  chlorid  is  crystalline 
and  very  soluble  in  water.  It  seems  to  be  non- poisonous  when 
pure. 

Saprin — C4HieN2 — another  diamin  of  undetermined  constitution. 


334  MANUAL    OF    CHEMISTRY 

has  been  obtained  from  putrid  spleens  and  livers  after  three  weeks' 
putrefaction. 

Mydalein  is  still  another  putrid  product  of  undetermined  compo- 
sition, but  probably  a  diamin  containing  four  or  five  carbon  atoms, 
which  forms  a  difficultly  crystallizable,  hygroscopic  chlorid,  which  is 
actively  poisonous.  Five  milligrams  administered  hypodermically  to 
a  cat  causes  death  after  profuse  diarrhoea  and  secretion  of  saliva,  vio- 
lent convulsions  and  paralysis,  beginning  with  the  extremities  and 

extending  to  the  muscles  of  respiration. 

CH2v 
Spermin  —  C2H5N  —  probably   ethylene-imin,   I     /NH,    has   been 

CH2 

obtained  from  semen,  testicles,  ovaries,  prostate,  thyroid,  pancreas, 
and  spleen.  Its  phosphate  forms  crystals,  known  as  Leyden, 
Bottcher's,  or  Charcot's  crystals,  which  are  met  with  in  anatomical 
preparations  preserved  in  alcohol,  in  dried  semen,  in  sputa  and  nasal 
secretions,  in  the  blood,  spleen,  and  other  organs  of  Ieucocytha3mics 
and  ana3mics,  and  in  fa3ces.  A  substance,  probably  identical  with 
spermin,  is  also  found  in  the  cultures  of  the  comma  bacillus  on  beef- 
broth.  The  free  base  forms  crystals,  which  rapidly  absorb  carbon 
dioxid  from  air,  are  readily  soluble  in  water  and  in  alcohol,  insoluble 
in  ether,  and  strongly  alkaline  in  reaction.  The  Charcot  crystals  are 
insoluble  in  alcohol,  ether  and  chloroform,  difficultly  soluble  in  water, 
easily  soluble  in  dilute  acids  or  alkalies. 

The  imins,  also  called  imids  (but  see  p.  347),  are  formed  by  the 
substitution  of  bivalent  hydrocarbon  groups  for  two  hydrogen  atoms 
in  a  single  molecule  of  ammonia;  the  diimins,  also  called  diamids,  by 
the  substitution  of  two  such  groups  for  four  hydrogen  atoms  in  two 
molecules  of  ammonia.  These  compounds  are  cyclic,  and  include 
some  important  members  of  the  aromatic  series. 

When  the  diammonium  chlorids  are  heated  ammonium  chlorid  is 
split  off,  and  an  imin  or  a  diimin  is  formed.  Thus  piperidin  (p.  461) 
is  produced  from  pentamethylene  diamin  ;  and  piperazin  (p.  462) 
from  ethylene  diamin  : 


AMIDINS  —  AMIDOXIMS  —  HYDROXAMIC    ACIDS  . 

The  amidins  contain  both  the  amido  group,  NH2,  and  the  imido 
group,  NH,  and  have  the  general  formula:  R-C^H2'  m  which  R  is 
any  univalent  hydrocarbon  radical. 


NITROGEN    DERIVATIVES    OF    THE    PARAFFINS  335 

They  are  formed  by  heating  the  nitrils  (p.  340)  with  ammonium 
chlorid.      Thus   acetonitril   yields   acetamidin :  CHa.CiN+NEUCl^ 

HCl-f  CH3.C<^H2-  They  are  also  formed  by  action  of  HC1  upon  the 
amids.  Indeed,  they  may  be  considered  as  being  derived  from  the 
amids  (p.  345)  by  substitution  of  NH  for  the  carbonyl  oxygen  : 

CH3.C^oH2»  acetamid  :  CH3.C^12'  acetamidin.  The  amidins  are 
monacid  bases,  very  unstable  when  free. 

The  amidoxims  are  derived  from  the  amidins  by  substitution  of 
OH  for  hydrogen,  e.g.,  CH3.C^N  O2H,  ethenylamidoxim.     They  are 

very  unstable  compounds,  formed  by  the  action  of  hydroxylamin 
upon  nitrils  or  upon  amidins  (p.  360). 

Hydroxamic   acids   contain   the    oxim  group,  N.OH,   while   the 
amido  group  of  the  amidin  is  replaced  by  hydroxyl  : 
acetohydroxamic  acid. 


GUANIDIN    AND    ITS    DERIVATIVES. 

Guanidin — Carbotriamin — CH5N3 — was  first  obtained  by  oxidation 
of  guanin  (p.  357).  Its  synthesis  has  been  accomplished  by  heating 
together  ethyl  orthocarbonate,  C(OC2Hs)4,  and  NH3.  It  is  a  crystal- 
line substance,  which  absorbs  C(>2  and  EbO  from  the  air,  and  forms 
crystalline  salts.  Some  of  its  derivatives  are  important  physio- 
logically. 

/NTT 

Guanidin,  containing  the  group  .C^NH2,  is  an  amidin.  It  may  also 
be  considered  as  a  triamin,  derived  from  three  ammonia  molecules, 

/NTT 

H2N — C<^NH2.     It  is  related  to  amidocarbonic  acid,  to  urea  and  to 
pseudourea,  as  is  indicated  by  the  formulae: 

NH_C/NH2       0_C/NH2       NH_C/NH2       Q_r/NH2 
C\NH2  °\NH2  C\OH  C\OH 

Guanidin.  Urea.  Pseudourea.         Amido  carbonic 

acid. 

Methyl-guanidin  —  Methyluramin—  HN :  C(NH2)  NH  ( CH3)—  was 
first  obtained  by  the  oxidation  of  creatin  and  of  creatinin  (see  below). 
It  has  also  been  obtained  as  a  product  of  putrefaction  of  mus- 
cular tissue  at  a  low  temperature  in  closed  vessels,  when  it  probably 
results  from  the  decomposition  of  creatin.  It  is  a  colorless, 
crystalline,  deliquescent,  strongly  alkaline  substance,  and  is  highly 
poisonous. 

The  relation  of  guanidin  and  methyl -guanidin  to  each  other  and 
to  creatin  and  creatinin  is  shown  by  the  following  formulas  : 


336  MANUAL    OF    CHEMISTRY 


'\N(CH3).CH2.COOH 
Guanidin.  Creatin. 

TTXT r1/  NH2  yNH        CO 

L\NH(CH3)  HN=C< 

XN(CH3)CH2 
Methyl-guanidin.  Creatinin. 


Creatin  —  Methyl-guanidin  acetic  acid  —  C4H9N302+Aq  —  is,  as  is 
shown  by  the  above  graphic  formula,  a  complex  amido-acid  (p.  361). 
It  is  a  normal  constituent  of  the  juices  of  muscular  tissue,  brain, 
blood,  and  amniotic  fluid.  It  is  formed  synthetically  by  the  union 
of  methyl  glycocoll  (p.  363),  and  cyanamid  (p.  344)  :  CH2(NH.CH3).- 


It  is  best  obtained  from  the  flesh  of  the  fowl,  which  contains  0.32 
per  cent.,  or  from  beef  -heart,  which  contains  0.14  per  cent.  It  is 
soluble  in  boiling  E^O  and  in  alcohol,  insoluble  in  ether;  crystallizes 
in  brilliant,  oblique,  rhombic  prisms;  neutral;  tasteless;  loses  Aq  at 
100°  (212°  F.)  ;  fuses  and  decomposes  at  higher  temperatures.  When 
long  heated  with  H2O,  or  treated  with  concentrated  acids,  it  loses 
IkO,  and  is  converted  into  creatinin.  Baryta  water  decomposes  it 
into  sarcosin  and  urea.  It  is  not  precipitated  by  silver  nitrate,  ex- 
cept when  it  is  in  excess  and  in  presence  of  a  small  quantity  of  po- 
tassium hydroxid.  The  white  precipitate  so  obtained  is  soluble  in 
excess  of  potash,  from  which  a  jelly  separates,  which  turns  black, 
slowly  at  ordinary  temperatures,  rapidly  at  100°  (212°  F.).  A  white 
precipitate,  which  turns  black  when  heated,  it  also  formed  when  a 
solution  of  creatin  is  similarly  treated  with  mercuric  chlorid  and 
potash. 

Creatinin  —  Methyl  guanidin  acetic  lactam  —  C^yNsO  —  113  —  a 
product  of  the  dehydration  of  creatin,  is  a  normal  and  constant  con- 
stituent of  the  urine  and  amniotic  fluid,  and  also  exists  in  the  blood 
and  muscular  tissue. 

It  crystallizes  in  oblique,  rhombic  prisms,  soluble  in  H2O  and  in 
hot  alcohol,  insoluble  in  ether.  It  is  a  strong  base,  has  an  alkaline 
taste  and  reaction;  expels  NHa  from  the  ammoniacal  salts,  and  forms 
well-defined  salts,  among  which  is  the  double  chlorid  of  zinc  and 
creatinin  (C^NaOhZnC^,  obtained  in  very  sparingly  soluble, 
oblique  prismatic  crystals,  when  alcoholic  solutions  of  creatinin  and 
zinc  chlorid  are  mixed. 

Ly  satin  —  CeHisNsC^,  or  Lysatinin  —  CeHnNaO-hH^O  —  one  of  the 
hexon  bases,  formed  in  the  decomposition  of  protein  bodies,  is  a 
superior  homologue  of  creatin  or  of  creatinin. 

Cruso-creatinin  —  CsHgN^  —  is  an  orange  -yellow,  crystalline  solid, 
alkaline  in  reaction  ;  Xantho-creatinin—  CsHw^O  —  is  in  yellow  crys- 


NITROGEN    DERIVATIVES    OF    THE    PARAFFINS  337 


talline  plates;  Amphi-creatinin  —  CgHigNTC^  —  forms  yellowish  -white 
prismatic  crystals.  These  are  basic  substances,  forming  crystalline 
chlorids,  and  belonging  to  the  class  of  leucomains,  which  include 
alkaloidal  substances  produced  by  physiological  processes.  (See  p. 
496).  They  are  obtained  from  the  juices  of  muscular  tissue,  and 
from  Liebig's  meat  extract,  in  which  they  accompany  creatin  and 
creatinin. 

HYDBAZINS. 

The  hydrazins  are  derivatives  of  the  hypothetical  diamidogen, 
H2N.NH2  (p.  105),  by  substitution  of  aliphatic  or  aromatic  radicals, 
alcoholic,  phenolic  or  acid,  for  one  or  more  of  the  hydrogen  atoms 
in  the  same  way  as  the  amins  are  derived  from  ammonia.  There  are, 
therefore,  primary,  secondary,  tertiary  and  quarternary  hydrazins; 
and  they  may  be  symmetrical,  as  C2Hs.HN.NH.C2H5  and  CeHs.- 
HN.NH.C2H5,  or  unsymmetrical,  as  C6H5.HN.NH2  and  (CfcHa)sN.- 
NH2.  The  aliphatic  hydrazins  are  obtained  from  the  alky  1-  ureas, 
by  conversion  into  nitroso-  amins,  and  reduction.  Most  of  the  hydra- 
zins,  some  of  which  are  of  considerable  interest,  are  derivatives  of 
phenyl-hydrazin,  C6H5.HN.NH2,  and,  containing  a  cyclic  chain  C6H5, 
will  be  considered  among  the  aromatic  compounds. 


NITRILS  —  AZOPARAFFINS  —  CYANOGEN  COMPOUNDS . 

These  substances  may  be  considered  either  as  compounds  of  the 
univalent  radical  cyanogen  (Civ  N'")';  or  as  paraffins,  CnH2n+2,  in 
which  three  atoms  of  hydrogen  have  been  replaced  by  the  trivalent 
N'"  atom,  hence  azoparaffins ;  or  as  nitrils,  compounds  of  N  with 
the  trivalent  radicals  CnH2n-i. 

Hydrogen  Cyanid — Formonitril — Cyanogen  hydrid — Hydrocyanic 
acid  —  Prussic  acid  —  HCIN — exists  ready  formed  in  the  juice  of 
cassava,  and  is  formed  by  the  action  of  H2O  upon  bitter  almonds, 
cherry-laurel  leaves,  and  other  vegetable  products  containing  amyg- 
dalin,  a  glucosid,  which  is  decomposed  into  glucose,  benzoic  aldehyde 
(p.  410),  and  hydrocyanic  acid,  when  warmed  with  water.  It  is  also 
formed  in  a  great  number  of  reactions:  by  the  passage  of  the 
electric  discharge  through  a  mixture  of  acetylene  and  nitrogen: 
HC:CH  +  N2=2HC:N;  by  the  action  of  chloroform  on  ammonia: 
NH3  +  CHC13=  3HC1  +  HCN;  by  the  distillation  of,  or  the  action  of 
HNOa  upon,  many  organic  substances;  by  the  decomposition  of 
cyanids  (see  Nitrils,  below). 

It  is  always  prepared  by  the  decomposition  of  a  cyanid  or  a 
ferrocyanid,  usually  by  acting  upon  potassium  ferrocyanid  with 
22 


338  MANUAL    OF    CHEMISTRY 

dilute  sulfuric  acid,  and  distilling.  Its  preparation  in  the  pure 
form  is  an  operation  attended  with  the  most  serious  danger,  and 
should  only  be  attempted  by  those  well  trained  in  chemical  manip- 
ulation. For  medical  uses  a  very  dilute  acid  is  required;  the  acid, 
hydrocyanicum  dil.  (U.  S.  Br.)  contains,  if  freshly  and  properly 
prepared,  two  per  cent,  of  anhydrous  acid.  That  of  the  French 
Codex  is  much  stronger — ten  per  cent. 

The  pure  acid  is  a  colorless,  mobile  liquid,  has  a  penetrating  and 
characteristic  odor;  sp.  gr.  0.7058  at  7°  (44.6°  F.);  crystallizes  at 
-15°  (5°  F.);  boils  at  26.5°  (79.7°  F.);  is  rapidly  decomposed  by 
exposure  to  light.  The  dilute  acid  of  the  U.  S.  P.  is  a  colorless 
liquid,  having  the  odor  of  the  acid;  faintly  acid,  the  reddened  litmus 
returning  to  blue  on  exposure  to  air;  sp.  gr.  0.997;  10  grams  of 
the  acid  should  react  without  excess  with  1.27  gram  of  silver  nitrate. 
The  dilute  acid  deteriorates  on  exposure  to  light,  although  more 
slowly  than  the  concentrated;  a  trace  of  phosphoric  acid  added  to 
the  solution  retards  the  decomposition. 

Most  strong  acids  decompose  HCN.  The  alkalies  enter  into  double 
decomposition  with  it  to  form  cyanids.  It  is  decomposed  by  Cl  and 
Br,  with  formation  of  cyanogen  chlorid  or  bromid.  Nascent  H  con- 
verts it  into  methylamin. 

Analytical  Characters. — (1)  With  silver  nitrate:  a  dense,  white 
ppt.;  which  is  not  dissolved  on  addition  of  HNOs  to  the  liquid,  but 
dissolves  when  separated  and  heated  with  concentrated  HNOs;  solu- 
ble in  solutions  of  alkaline  cyanids  or  thiosulfates.  (2)  Treated 
with  NHtHS,  evaporated  to  dry  ness,  and  ferric  chlorid  added  to  the 
residue:  a  blood-red  color,  which  is  discharged  by  mercuric  chlorid. 
(3)  With  potash  and  then  a  mixture  of  ferrous  and  ferric  sulfates: 
a  greenish  ppt.,  which  is  partly  dissolved  by  HC1,  leaving  a  pure 
dark -blue  precipitate.  (4)  Heated  with  a  dilute  solution  of  picric 
acid  and  then  cooled  :  a  deep -red  color.  (5)  Moisten  a  piece  of 
filter- paper  with  a  freshly  prepared  alcoholic  solution  of  guaiac;  dip 
the  paper  into  a  very  dilute  solution  of  CuSO4,  and,  after  drying, 
into  the  liquid  to  be  tested.  In  the  presence  of  HCN  it  assumes  a 
deep -blue  color.  (6)  Add  a  few  drops  of  potassium  nitrite  solution, 
then  two  or  three  drops  of  ferric  chlorid  solution,  and  enough  dilute 
H2SO4  to  turn  the  color  to  yellow.  Heat  just  to  boiling;  cool,  add 
a  few  drops  of  NHtHO,  filter,  and  add  to  the  filtrate  a  few  drops 
of  dilute,  colorless  ammonium  sulf hydrate:  a  violet  color,  changing 
to  blue,  then  to  green  and  yellow  (p.  345). 

Toxicology.  —  Hydrocyanic  acid  is  a  violent  poison,  whether  it  be 
inhaled  as  vapor,  or  swallowed,  either  in  the  form  of  dilute  acid,  of 
soluble  cyanid,  or  of  the  pharmaceutical  preparations  containing  it, 
such  as  oil  of  bitter  almonds  and  cherry-laurel  water;  its  action  being 


NITROGEN    DERIVATIVES    OF    THE    PARAFFINS  339 

more  rapid  when  taken  by  inhalation  or  in  aqueous  solution  than  in 
other  forms.  When  the  medicinal  acid  is  taken  in  poisonous  dose, 
its  lethal  effect  may  seem  to  be  produced  instantaneously;  nevertheless, 
several  respiratory  efforts  usually  are  made  after  the  victim  seems  to 
be  dead,  and  instances  are  not  wanting  in  which  there  was  time  for 
considerable  voluntary  motion  between  the  time  of  ingestion  of  the 
poison  and  unconsciousness.  In  the  great  majority  of  cases  the 
patient  is  either  dead  or  fully  under  the  influence  of  the  poison  on 
the  arrival  of  the  physician,  who  should,  however,  not  neglect  to 
apply  the  proper  remedies  if  the  faintest  spark  of  life  remain. 
Chemical  antidotes  are,  owing  to  the  rapidity  of  action  of  the  poison, 
of  no  avail,  although  possibly  chlorin,  recommended  as  an  antidote 
by  many,  may  have  a  chemical  action  on  that  portion  of  the  acid 
already  absorbed.  The  treatment  indicated  is  directed  to  the  main- 
tenance of  respiration;  cold  douche,  galvanism,  artificial  respiration, 
until  elimination  has  removed  the  poison.  If  the  patient  survive 
an  hour  after  taking  the  poison,  the  prognosis  becomes  very  favor- 
able; in  the  first  stages  it  is  exceedingly  unfavorable,  unless  the 
quantity  taken  has  been  very  small. 

In  cases  of  death  from  hydrocyanic  acid  the  odor  of  the  poison 
may  be  observed  in  the  apartment,  or  upon  opening  the  body.  In 
cases  of  suicide  or  accident,  the  vessel  from  which  the  poison  has 
been  taken  will  usually  be  found  in  close  proximity  to  the  body, 
although  the  absence  of  such  vessel  is  not  proof  that  the  case  is 
necessarily  one  of  homicide. 

Notwithstanding  the  volatility  and  instability  of  the  poison,  its 
presence  has  been  detected  two  months  after  death,  although  the 
chances  of  separating  it  are  certainly  the  better  the  sooner  after 
death  the  analysis  is  made.  The  search  for  hydrocyanic  acid  is 
combined  with  that  of  phosphorus;  the  part  of  the  distillate  con- 
taining the  more  volatile  products  is  examined  by  the  tests  given 
above.  It  is  best,  when  the  presence  of  free  hydrocyanic  acid  is 
suspected,  to  distil  at  first  without  acidulating.  In  cases  of  sus- 
pected homicide  by  hydrocyanic  acid,  the  stomach  should  never  be 
opened  until  immediately  before  the  analysis. 

Cyanogen  Chlorids. — Two  polymeric  chlorids  are  known:  Cyano- 
gen chlorid,  CNC1,  formed  by  the  action  of  Cl  upon  anhydrous  HCN 
or  upon  Hg(CN)2  in  the  dark.  It  is  a  colorless  gas,  condensing 
to  a  liquid  at  15°  (59°  F.);  intensely  irritating  and  poisonous. 
Tricyanogen  chlorid,  C3N3Cl3,  is  formed,  as  a  crystalline  solid,  when 
anhydrous  HCN  is  acted  upon  by  Cl  in  sunlight.  It  fuses  at  146° 
(294.8°  F.). 

Cyanids. — The  most  important  of  the  simple  metallic  cyanids  are 
those  of  K  and  Ag  (pp.  181,  184,  also  p.  344). 


340  MANUAL    OF    CHEMISTRY 

Nitrils. — The  hydrocyanic  esters  of  the  univalent  alcoholic  rad- 
icals are  called  acid  nitrils,  because  of  their  formation  from  the 
amids  (p.  345),  by  the  reaction  given  under  (3)  below.  Hydro- 
cyanic acid,  being  produced  from  formamid,  is  formonitril;  methyl 
cyanid,  derived  from  acetamid,  is  acetonitril,  etc.  They  are  also 
derivable  from  the  ammonium  salt  of  the  acid  by  elimination  of  the 
elements  of  two  molecules  of  water.  Their  formula  may  be  derived 
from  those  of  the  acids  by  substitution  of  N  for  the  trivalent  OOH 
of  the  carboxyl. 

The  nitrils  are  produced:  (1)  By  heating  the  haloid  esters  (p. 
233)  with  alcoholic  solution  of  potassium  cyanid  at  100°:  CH3.CH2I- 
+KCN  =  CH3.CH2.CJSH-KI.  (2)  By  distilling  a  mixture  of  potas- 
sium cyanid  and  the  potassium  salt  of  a  monoalkyl  sulfate.  Thus, 
ethyl  cyanid  is  produced  from  potassium  ethylsulf ate :  KCN+SO4.- 
C2H5.K  =  K2SO4+C2H5.CN.  (3)  By  complete  dehydration,  by  the 
action  of  P2O5,  of  the  ammoniacal  salt  of  the  acid,  or  of  its  amid 
(p.  346).  Thus  acetonitril  is  obtained  from  ammonium  acetate: 
CH3.COO(NH4)=CH3.CN-f  2H2O;  or  from  acetamid:  CH3.CO.NH2- 
=CH3.CN+H20.  (4)  By  the  action  of  acidyl  chlorids  upon  silver 
cyanate.  Thus,  with  acetyl  chlorid,  methyl  cyanid  is  formed : 
CNOAg-hCH3.CO.Cl  =  AffCl+COH-CHg.CN. 

The  nitrils  combine  with  nascent  hydrogen  to  form  primary 
amins.  Thus  acetonitril  forms  ethylamin:  CH3.CN+2H2=C2H5.NH2. 
Hydrating  agents  convert  them  into  the  ammonium  salts  of  the  cor- 
responding acids.  Thus  ammonium  propionate  is  derived  from  ethyl 
cyanid:  C2H5.CN-f  2H2O=C2H5.COO(NH4).  Or,  when  acted  upon  by 
concentrated  sulfuric  acid,  hydrogen  peroxid,  or  concentrated  hydro- 
chloric acid,  they  take  up  one  molecule  of  water  and  form  amids 
(p.  346).  Thus  acetonitril  forms  acetamid:  CH3.CN+H2O  =  CH3.- 
CO.NH2. 

Methyl  Cyanid — Acetonitril  —  CH3.CN  —  is  a  colorless  liquid, 
b.  p.  81.6°,  having  an  agreeable  odor,  sparingly  soluble  in  water, 
obtained  by  distilling  ammonium  acetate  or  acetamid  with  P2Os. 

The  isocyanids,  carbylamins,  or  carbamins  are  isomeres  of  the 
nitrils,  which  differ  from  the  latter  in  constitution  in  that,  in  the 
nitrils,  the  nitrogen  is  trivalent,  and  the  alkyl  group  is  in  union 
with  carbon,  e.g.,  methyl  cyanid,  N=C — CH3,  while  in  the  carbyl- 
amins the  nitrogen  is  quinquevalent,  and  the  alkyl  is  in  union  with 
nitrogen,  e.  g.,  methyl  isocyanid,  C=N — CH3.  The  isocyanids,  when 
acted  upon  by  hydrating  agents,  do  not  yield  ammonium  salts  of  the 
corresponding  acids,  as  do  the  nitrils  (see  above),  but  are  decomposed 
into  formic  acid  and  a  primary  amin.  Thus  ethyl  isocyanid  does  not 
yield  propionic  acid,  but  formic  acid  and  ethylamin  :  NC.C2H5+ 
2H2O=H.COOH-fC2H5.NH2. 


NITROGEN    DERIVATIVES    OF    THE    PARAFFINS  341 

The  isocyanids  are  formed:  (1)  by  the  action  of  a  primary  mona- 
min  on  chloroform  in  the  presence  of  caustic  potash.  Thus  methyl 
isocyanid  is  derived  from  methylamin  :  CH3.NH2-f  CHC13=3HC1+ 
NC.CHs.  (pp.  235,  328) ;  (2)  by  the  action  of  alkyl  iodids  upon  silver 
cyanid:  CH3I+AgCN=AgI+NC.CH3. 

Methyl  Isocyanid — Methyl  carbylamin — Isoacetonitril — CH3.NC — 
is  a  colorless  liquid,  b.  p.,  58°,  having  a  disagreeable  odor,  and  giv- 
ing off  highly  poisonous  vapor.  It  is  formed  by  the  reactions  given 
above,  and  is  said  to  exist  in  the  venom  of  toads. 

Phenyl  Isocyanid — Isobenzonitril — CeHs.NC — is  a  colorless  liquid, 
not  boiling  without  decomposition,  having  an  intensely  disagreeable 
odor,  whose  formation  is  utilized  in  a  test  for  chloroform  (p.  235). 

Both  nitrils  and  isonitrils  combine  with  the  hydracids  to  form 
crystalline  salts,  decomposable  by  water;  the  latter  much  more  en- 
ergetically than  the  former.  They  are  all  volatile  liquids;  the  nitrils 
having  ethereal  odors  when  pure,  the  isonitrils  odors  which  are  very 
powerful  and  disagreable. 

Nitrils  of  the  Oxyacids.— The  nitrils  of  the  a- acids  of  the  oxy- 
acetic  series  (p.  290)  are  also  called  cyanhydrins,  or  oxycyanids,  and 
bear  the  same  relation  to  the  acids,  as  exists  between  the  acids  of  the 
acetic  series  and  their  nitrils  : 

CH3.COOH  CH3.CN 

Acetic  acid.  Acetonitril. 

CH3.CHOH.COOH  CH3.CHOH.CN 

a-lactic  acid.  Lactic  nitril. 

They  are  formed  as  additive  products  between  hydrocyanic  acid 
and  the  aldehydes  and  ketones:  HCN+CH3.CHO=CH3.CHOH.CN, 
and  HCN+CH3.CO.CH3=^^>C/gg  By  hydration  they  yield  the 

corresponding  acid  and  ammonia  :  CH3.CHOH.CN-h2H2O=:CH3.- 
CHOH.COOH+NH3.  These  reactions  are  utilized  in  the  synthesis 
of  theoxyacids  (p.  290). 

Nitrils  of  the  Ketone  Acids. — These  are  the  cyanids  of  the 
acidyls,  as  the  nitrils  are  the  cyanids  of  the  alkyls,  and  are  formed 
by  heating  the  acidyl  chlorids  with  silver  cyanid.  Thus  acetyl  cyanid 
is  produced  from  acetyl  chlorid  :  CH3.CO.Cl-f-AgCN=CH3.CO.CN+ 
AgCl;  or  by  dehydration  of  the  aldoxims  (p.  360)  of  the  a-aldehyde 
ketones.  Thus  oximido- acetone  yields  acetyl  cyanid:  CH3.CO.CH:- 
N.OH=CH3.CO.CN+H2O.  They  are  unstable,  and  are  decomposed 
by  water  into  hydrocyanic  acid  and  their  corresponding  acids:  CHa.- 
CO.CN+H2O=CH3.COOH+CNH. 

Nitrils  of  Dicarboxylic  Acids.— Two  nitrils  are  derivable  from  a 
dicarboxylic  acid,  one  being  a  nitrilic  acid,  the  other  a  dinitril.  The 


342  MANUAL    OF    CHEMISTRY 

nitrilic  acid  of  oxalic  acid  is  only  known  in  its  esters ;  its  dinitril  is 
dicyanogen  : 

COOH  CO(NH2)  COO(C2H5)  CN 

III  I 

COOH  CO(NH2)  CN  CN 

Oxalic  acid.  Oxamid.  Oxalnitrilic  Dicyanogen. 

ethyl  ester. 

Dicyanogen — CN.CN — is  prepared  by  heating  mercuric  cyanid, 
and  is  also  formed  by  passing  an  electric  arc  between  carbon  points 
in  an  atmosphere  of  nitrogen. 

It  is  a  colorless  gas,  has  a  pronounced  odor  of  bitter  almonds; 
sp.  gr.,  1.8064  A.  It  burns  in  air  with  a  purple  flame,  giving  off  N 
and  C02.  It  is  quite  soluble  in  water,  but  the  solutions  soon  turn 
brown,  and  then  contain  ammonium  oxalate  and  formate,  urea,  and 
hydrocyanic  acid.  The  brown  color  is  due  to  the  formation  of  azul- 
mic  acid,  C4H5N5O. 

Succinonitril — Ethylene  cyanid — CN.CH2.CH2.CN — is  the  dinitril 
of  succinic  acid.  It  is  an  amorphous  solid,  soluble  in  water,  alcohol, 
and  chloroform.  Fuses  at  55°  (131°  F.) . 

Nitrils  of  Carbonic  and  Thiocarbonic  Acids. — These  constitute 
the  oxygen  and  sulfur  compounds  of  cyanogen.  Thus  cyanic  acid 
is  the  nitril  of  carbonic  acid:  CO3H(NH4)  =  CONH+2H2O,  and 
thiocyanic  acid  that  of  thiocarbonic  acid  :  CO2SH(NH4)— CSNH+ 
2H2O. 

Three  structural  formula  of  these  compounds  are  possible:  N=C.- 
OH,  O=O=N.H,  and  C^N.OH.  The  first  structure  is  that  of  the 
normal  cyanic  and  thiocyanic  acids,  the  second  that  of  the  isocyanates 
and  isothiocyanates,  the  third  that  of  fulminic  acid. 

Cyanic  Acid — NC.OH — is  obtained  by  distillation  of  cyanuric 
acid,  or,  in  its  salts,  by  calcining  the  cyanids  in  presence  of  an  oxi- 
dizing agent,  or  by  the  action  of  dicyanogen  upon  solutions  of  the 
alkalies  or  alkaline  carbonates. 

It  is  a  colorless  liquid,  only  stable  below  0°  (32°  F.) ;  has  a  strong 
odor,  resembling  that  of  formic  acid;  and  is  soluble  in  water;  gives 
off  an  irritating  vapor;  is  vesicating  to  the  skin;  and  is  changed  by  ex- 
posure to  air  into  its  polymere,  cyamelid,  a  white,  porcelain -like 
solid. 

HO.CrN.C.OH 

I         II 

Cyanuric  Acid — Tricyanic  acid —       N:C.N       — is   produced    by 

OH 

dry  distillation  of  uric  acid ;  by  the  action  of  heat  or  of  Cl  upon  urea ; 
by  heating  tricyanogen  chlorid  or  bromid  with  water  or  with  alkalies. 
It  forms  colorless  crystals,  odorless,  almost  tasteless,  feebly  acid, 
rather  soluble  in  water.  It  is  tribasic.  It  may  be  dissolved  in  strong 


NITROGEN    DERIVATIVES    OF    THE    PARAFFINS  343 

H2S04  or  HNOs  without  decomposition,  but,  when  boiled  with  acids 
or  alkalies,  it  is  decomposed  into  carbon  dioxid  and  ammonia;  and, 
when  distilled,  into  cyanic  acid. 

The  ordinary  potassium  and  ammonium  cyanates  are  regarded  as 
isocyanates,  salts  of  isocyanic  acid,  or  carbimid,  O:C:NH.  The 
ammonium  salt,  O:C:N(NH4),  is  converted  into  its  isomere,  urea, 
H2N.CO.NH2,  by  evaporation  of  its  solution.  The  isocyanic  esters 
serve  for  the  generation  of  the  alkyl  ureas  (p.  350). 

Fulminic  Acid — Carbyloxim — C=N.OH — is  a  strongly  acid  sub- 
stance, having  the  odor  and  poisonous  qualities  of  hydrocyanic  acid, 
whose  Ag  and  Hg  salts  are  formed  by  the  action  of  nitrous  acid  upon 
alcohol  and  silver,  or  mercuric,  nitrate.  Mercuric  fulminate,  or 
fulminating  mercury,  crystallizes  in  white,  soluble  needles,  and  ex- 
plodes violently  upon  shock.  It  is  used  in  percussion  caps,  primers 
and  cartridges.  Silver  fulminate  is  more  violently  explosive  than 
the  mercurial  salt.  Fulminating  gold  is  not  a  fulminate,  but  auro- 
amidoimid,  Au(NH)NH2+3H20. 

./OTT 

Fulminuric  Acid — CN.CH(N02).C^NH  —  metameric  with  cya- 
nuric,  and  polymeric  with  cyanic  and  isocyanic  acids,  is  a  deriva- 
tive of  tartronic  acid,  COOH.CHOH.COOH  ;  whose  alkali  salts  are 
formed  by  boiling  solutions  of  alkaline  chlorids  with  mercuric 
fulminate. 

Thiocyanic  Acid — Sulfocyanic  acid — Cyanogen  sulfhydrate — N^ 
C.SH — is  obtained  by  decomposition  of  its  salts,  which  are  formed  by 
boiling  solutions  of  the  cyanids  with  sulfur;  by  the  action  of  dicya- 
nogen  upon  the  metallic  sulfids;  and  in  several  other  ways. 

The  free  acid  is  a  colorless  liquid,  crystallizes  at  — 12.5°  (9.5°  F.), 
acid  in  reaction.  The  prominent  reaction  of  the  acid  and  of  its  salts 
is  the  formation  of  a  deep -red  color  with  the  ferric  salts;  the  color 
being  discharged  by  mercuric  chlorid  solution. 

\  -  Thiocyanates  exist  in  the  human  saliva  and  in  the  stomach -con- 
tents, in  small  amount.  The  free  acid  is  poisonous. 

Isothiocyanic  Esters — Mustard  oils — Isothiocyanic  acid,  S:C:- 
NH,  is  not  known  in  the  free  state.  Its  esters  are  called  mustard 
oils,  from  the  most  important  of  the  class,  allyl  isothiocyanate 
(p.  377),  which  is  the  essential  oil  of  mustard. 

The  mustard  oils  are  obtained  :  (1)  by  mixing  ether  solutions  of 
primary  amins  and  carbon  disulfid,  and  evaporating  the  solutions,  the 
amin  salts  of  alkyl  dithiocarbamic  acids  are  formed  (p.  350) :  CS2+ 

2C2H5.NH2^SC<(s(NH3Hc2H5)-  On  boiling  aqueous  solutions  of  these 
with  AgNOs,  Fe2Cl6  or  HgCl2,  the  metallic  sulfids  are  precipitated, 
and  hydrogen  sulfid  and  the  mustard  oils  are  formed,  the  latter  dis- 
tilling over.  The  reaction  takes  place  in  two  stages  : 


344  MANUAL    OF    CHEMISTRY 

sr/NH.C2H5  ,         .    N0  _or/NH.C2H5  NO    N^H3 

^\S(NH3.C2H5)  \SAg  *U|'K  and 


Ethyl&mmonium  Silver  Silver  Ethylammonium 

ethylthiocarbamate.  nitrate,      ethyldithiocarbamate.  nitrate. 

Ag2S    -f    H2S     +     2SC:N.C2H5 
Ethyl  isocyanate. 

Hoffmann'  s  test  for  the  primary  amins  (p.  328)  is  based  upon 
these  reactions. 

The  mustard  oils  are  liquids,  insoluble  in  water,  giving  off  vapors 
of  penetrating  odor  and  irritating  to  the  eyes.  When  heated  with 
water  under  pressure  to  200°  (392°  F.),  or  with  hydrochloric  acid  to 
100°  (212°  F.),  they  are  decomposed  into  carbon  dioxid,  hydrogen 
sulfid  and  amins:  SC:N.C2H5+2H2O=CO2+SH2-f  NH2.C2H5.  Heat- 
ing with  dilute  H2SO4  decomposes  them  into  amins  and  carbon  oxy- 
sulfid,  COS.  With  nascent  hydrogen  they  yield  thioform  aldehyde 
and  a  primary  amin:  SC:N.C2H5+2H<F=H.CSH-t-NH2.C2H5.  Heated 
with  monocarboxylic  acids  they  form  carbon  oxysulfid,  esters,  and 
monamids  (p.  345)  :  SC:N.C2H5+2CH3.COOH=COS+CH3.COO.- 
C2H5+NH2.CH3.CO.  Their  alcoholic  solutions,  when  boiled  with 
HgO,  yield  isocyanic  esters,  which  are  converted  by  water  into  the 
corresponding  compound  ureas. 

Cyanamid  —  CN.NH2  —  is  the  nitril  of  carbamic  acid  (p.  346)  : 
OC:NH2.O.NH4—  2H2O=CN.NH2.  It  is  formed  by  the  action  of 
cyanogen  chlorid  upon  ammonia  :  CNCl+2NH3=NH4Cl-hCN.NH2. 
It  forms  colorless  crystals,  soluble  in  water,  alcohol  or  ether.  Cor- 
responding to  it  are  substituted  cyanamids,  which  may  be  formed 
by  using  a  primary  amin  in  place  of  ammonia  in  the  above-mentioned 
method  of  preparation:  CNC1  +  2NH2.CH3  =  NH3.CH3.C1  -f  CN.- 
NHCH3. 

Metallocyanids.  —  The  metallic  compounds  of  cyanogen,  the  cya- 
nids,  may  be  divided  into  three  classes:  (1)  the  simple  cyanids,  such 
as  potassium,  silver,  or  mercuric  cyanid,  which  resemble  in  consti- 
tution and  general  characters  the  chlorids,  bromids  and  iodids;  (2) 
the  double  cyanids,  such  as  AgK(CN)2,  or  HgK2(CN)4,  which  are 
constituted  like  other  double  salts.  These  salts  have  crystalline 
forms  and  solubilities  of  their  own,  independent  of  those  of  the  sim- 
ple cyanids  of  which  they  are  made  up.  They  are  readily  decomposed 
by  cold  acids,  with  liberation  of  hydrocyanic  acid  ;  (3)  compound 
cyanids,  or  metallocyanids,  in  which  the  cyanogen  groups  are  more 
intimately  attached  to  the  metal,  in  such  manner  that  the  ordinary 
analytical  characters  of  the  metals  are  completely  masked;  and  when 
they  are  decomposed  by  cold  acids  hydrocyanic  acid  is  not  liberated, 
but  a  complex  metallohydrocyanic  acid,  corresponding  in  constitution 
to  the  salt.  The  metals  entering  into  the  composition  of  the  metal- 


NITROGEN    DERIVATIVES    OF    THE    PARAFFINS  345 

locyanids  are  iron  (ferro- and  ferricyanids),  cobalt  (cobalticyanids), 
and  platinum  (platinocyanids) ;  also  chromium  and  manganese  in  the 
ic  form. 

The  metallocyanids  are  considered  as  derivatives  of  two  hypo- 
thetical acids,  polymeres  of  hydrocyanic  acid  :  dihydrocyanic  acid 
and  trihydrocyanic  acid,  which,  in  the  hydrometallocyanic  acids  and 
their  salts  are  combined  with  the  constituent  metal,  with  loss  of  hy- 
drogen, as  shown  in  the  following  formulae  : 

H— C=N  H— C=N C— H 

II  I  II 

N=C— H  N=CH— N 

Dihydrocyanic  acid.  Trihydrocyanic  acid. 

Fe/C3H3.K 

F/C3H3.K2  I  \C3H3.K2  p./C2H2.H 

®\     f~i    TT       v  \      ^C\    TT       V  *^*^    (~*    TT       TT 

N^sHs.Xx1)  TTI    ^\^3±l3.JV  \U2-D.2'-tl 

e\C3H3.K2 

Potassium  Potassium  Hydroplatinocyanic 

ferrocyanid.  ferricyanid.  acid. 

Hydronitroprussic  Acid— Fe(CN )5( NO) H2— contains  the  nitroso 
group  NO,  and  is  produced  when  potassium  ferrocyanid  is  acted 
upon  by  nitric  acid.  Its  sodium  salt,  sodium  nitroprussid,  is 
formed  by  neutralizing  the  acid  with  sodium  carbonate.  It  forms 
brilliant  red  prisms;  and  is  used  as  a  test  for  sulfids,  with  which  it 
forms  a  violet  color.  (See  test  No.  6,  Hydrocyanic  acid,  p.  338.) 


AMIDS. 

These  compounds  are  similar  in  constitution  to  the  amins  (p. 326), 
from  which  they  differ  in  that  the  substituted  radicals  are  acid  in  place 
of  hydrocarbon  radicals. 

Like  the  amins  they  are  classified  into  monamids,  diamids,  tri- 
amids,  according  as  they  are  derived  from  one,  two  or  three  molecules 
of  ammonia. 

Mixed  amids  are  also  known,  produced  by  the  substitution  of  acid 
radicals  for  the  remaining  hydrogen  of  the  primary  and  secondary 
amins,  e.  g.,  diethyl  acetamid: 


MONAMIDS  —  AMIC    ACIDS  —  1MIDS . 

Like  the  monamins,  the  monamids  are  primary,  secondary,  or 
tertiary,  as  they  contain  one,  two,  or  three  substituted  radicals. 

The  primary  monamids  corresponding  to  the  monocarboxylic  acids 
may  also  be  considered  as  being  derived  from  those  acids  by  substi- 
tution of  NH2  for  the  OH  of  the  group  COOH.  Thus  acetamid, 
CH3.CO.NH2  is  derived  from  acetic  acid,  CH3.CO.OH. 


346  MANUAL    OP    CHEMISTRY 

The  primary  monamids  are  formed:  (1)  by  the  action  of  heat 
upon  the  ammonium  salt  of  the  acid,  with  elimination  of  the  elements 
of  one  molecule  of  water:  CH3.COO(NH4)=H2O+CH3.CO.NH2.  It 
will  be  remembered  that  the  nitrils  (p.  340)  are  derived  from  the 
ammoniacal  salts  by  elimination  of  two  molecules  of  water:  CHa.- 
COO(NH4)=2H20+CH3.CN;  (2)  by  addition  of  H20  to  the  nitrils. 
Thus  hydrogen  peroxid  in  alkaline  solution  converts  acetonitril  into 
acetamid:  2CH3.CN+2H2O2=2CH3.CO.NH2-h02;  (3)  by  the  action 
of  ammonia  upon  esters.  Thus,  ethyl  acetate  and  ammonia  produce 
acetamid  and  ethylic  alcohol:  CH3.COO(C2H5)+NH3=CH3.CO.- 
NH2+CH3.CH2OH;  (4)  by  the  action  of  an  acidyl  chlorid  upon  dry 
ammonia.  Thus,  acetamid  is  produced  by  acetyl  chlorid:  CHs.CO.- 
C1+2NH3  =NH4C1+CH3.CO.NH2. 

The  secondary  monamids  are  obtained:  (1)  by  the  action  of  acidyl 
chlorids  upon  the  primary  monamids.  Thus,  diacetamid  is  produced 
from  monacetamid:  CH3.CO.NH2+CH3.CO.C1=HC1+(CH3CO)2NH; 
(2)  by  the  action  of  hydrochloric  acid  upon  the  primary  monamids  at 
high  temperatures  ;  2(CH3.CO.NH2)-|-HC1=NH4C1+(CH3CO)2NH. 

The  tertiary  amids  of  this  series  have  been  imperfectly  studied. 
Some  have  been  obtained  by  the  action  of  acidyl  chlorids  upon  me- 
tallic derivatives  of  secondary  amids:  (CH3.CO)2NaN+CH3.CO.Cl— 
(CH3.CO)3N+NaCl;  or  by  the  union  of  anhydrids  and  nitrils  at  200° 
(392°  F.)  :  CH8.CN+(CH3.CO)20=(CH3.CO)8N. 

Monamids  are  also  formed  by  the  substitution  of  univalent  re- 
mainders of  dibasic  acids  for  the  hydrogen  of  a  single  molecule  of 
ammonia.  These  amic  acids  are  formed  by  carefully  distilling  the 
monoammonium  salt  of  the  acid.  Thus,  monoammonium  oxalate 
yields  oxamic  acid:  COOH.COO(NH4)=H2O+  COOH.CO.NH2. 

Or  they  may  be  obtained  from  the  imids  as  shown  below. 

Carbamic  Acid  —  OC\QH2  —  ^s  not  known  in  the  free  state.  Its 
ammonium  salt  exists  in  commercial  ammonium  carbonate,  and  is 
produced  by  direct  union  of  ammonia  and  carbon  dioxid  :  2NHs+ 
•  I*  also  exists  normally  in  the  urine,  and  is  prob- 


ably formed  in  the  system  as  an  intermediate  product  between  the 
amido  acids  and  urea.  Indeed,  carbarn  ic  acid  is  amido-  formic  acid 
(p.  362). 

The  esters  of  carbamic  acid,  called  urethans,  are  more  stable 
than  its  salts.  They  are  formed  by  the  action  of  ammonia  upon  the 
carbonic  esters:  OC:  (OC2H5)2+NH3=OC:NH2.OC2H5+CH3.CH2OH; 
also  by  the  action  of  cyanogen  chlorid  on  alcohols  :  CNC1H-2C2H5- 
OH=OC  :  NH2.OC2H5+C2H5C1. 

Ethyl  Urethan-—  OC:NH2.OC2H5—  is  formed  by  the  above  reac- 
tions. It  forms  thin,  large,  transparent  plates;  fusible  at  50°  (122° 


NITROGEN    DERIVATIVES    OF    THE    PARAFFINS  347 

F.)f  boiling  at  184°  (363.1°  F.),  very  soluble  in  alcohol  and  in  water. 
It  has  been  used  as  a  hypnotic,  either  alone  or  combined  with  chloral 
in  uralium,  or  somnal. 

Phenyl  Urethan — OC :  NH^.OCeHs — is  a  light  white  powder,  almost 
insoluble  in  water,  very  soluble  in  alcohol,  which  is  used  as  an  anti- 
pyretic under  the  name  euphorine. 

Two  atoms  of  hydrogen  in  a  single  molecule  of  ammonia  may  be 
replaced  in  a  bivalent  acid  radical;  in  which  case  an  imid  is  formed 
(p.  334).  The  imids  are  obtained  by  dehydration  of  the  mono- 
ammonium  salts  or  of  the  amic  acids.  Thus,  monoammonium  suc- 
cinate,  or  succinamic  acid  yields  succinimid : 

CH2.COOH  CH2.CO\  CH2.COOH       CH2.CO\ 

=  |  NH+2H20,    or    |  =  |  NH-f H2O. 

CH2.COO(NH4)     CH2.CO/  CH2.CO.NH2    CH2.CO/ 

Conversely  the  imids,  when  acted  upon  by  alkalies  or  baryta  water, 
are  converted  into  salts  of  the  amic  acids: 

CH2.CO\  CH2.COOK 

NH    +    KHO    =      | 
CH2.CO/  CH2.CO.NH2. 

The  primary  monamids  of  the  fatty  acids  are  solid,  crystallizable, 
neutral  in-  reaction,  volatile  without  decomposition,  mostly  soluble  in 
alcohol  and  ether,  and  mostly  capable  of  uniting  with  acids  to  form 
compounds  similar  in  constitution  to  the  ammoniacal  salts.  They  are 
capable  of  uniting  with  H2O  to  form  the  ammoniacal  salts  of  the  cor- 
responding acids,  and  with  the  alkaline  hydroxids  to  form  the  metallic 
salts  of  the  corresponding  acids  and  ammonia.  The  secondary  mon- 
amids, containing  two  radicals  of  the  fatty  series,  are  acid  in  reac- 
tion, and  their  remaining  atom  of  extra -radical  hydrogen  may  be 
replaced  by  an  electro -positive  atom. 

Formamid — CHO.NEb — 45 — is  a  colorless  liquid,  soluble  in  EbO 
and  in  alcohol,  boils  at  192°-195°  (377.6°-385°  F.),  suffering  partial 
decomposition,  obtained  by  heating  ethyl  formate  with  an  alcoholic 
solution  of  ammonia,  or  by  the  dry  distillation  of  ammonium  formate. 
It  is  decomposed  by  dehydrating  agents,  with  formation  of  hydro- 
cyanic acid.  Mercury  formamid  is  obtained  in  solution  by  gently 
heating  freshly -precipitated  mercuric  oxid  with  B^O  and  formamid. 

Under  the  name  chloralamid  a  compound,  formed  by  the  union  of 

/OTT 

chloral  and  formamid,  and  having  the  constitution,  CCl3CH<^NHc]jo, 
has  been  used  as  a  hypnotic.  It  forms  colorless,  odorless,  faintly 
bitter  crystals,  fusible  at  115°  (239°  F.),  sparingly  soluble  in  water. 
It  is  decomposed  by  alkalies,  chloroform  and  ammonia  being  among 
the  products  of  the  decomposition.  It  is  not  affected  by  acids. 


348  MANUAL    OF    CHEMISTRY 

Chloralimid — CCl3,C\H  — is  another  related  derivative,  formed 
by  the  action  of  ammonium  acetate  upon  chloral  hydrate,  or  by  the 
action  of  heat  upon  chloral  ammonia.  It  is  a  crystalline  solid,  spar- 
ingly soluble  in  water,  readily  soluble  in  ether  and  in  alcohol.  When 
heated  to  180°  (356°  F.)  it  is  decomposed  into  chloroform  and  form- 
am  id. 

Acetamid — CH3.CO.NH2 — is  obtained  by  heating,  under  pressure, 
a  mixture  of  ethyl  acetate  and  ammonium  hydroxid,  and  purifying  by 
distillation.  It  is  solid,  crystalline,  very  soluble  in  H2O,  alcohol,  and 
ether;  fuses  at  82°  (179.6°  F.);  boils  at  222°  (431. 6°  F.)  ;  has  a 
sweetish,  cooling  taste,  and  an  odor  of  mice.  Boiling  potassium  hy- 
droxid solution  decomposes  it  into  potassium  acetate  and  ammonia. 
Phosphoric  anhydrid  deprives  it  of  H2O,  and  forms  with  it  acetonitril 
or  methyl  cyanid. 

DIAMIDS. 

The  diamids  correspond  to  the  diamins  (p.  330).  They  are  de- 
rived from  two  molecules  of  ammonia  by  the  substitution  of  bivalent 
acid  radicals  for  an  equivalent  number  of  hydrogen  atoms.  Thus, 
oxamid:  H2N.(C2O2)".NH2;  and  carbamid,  H2N.(CO)".NH2. 

They  are  formed:  (1)  By  the  action  of  ammonia  upon  the  neutral 
esters.  Thus  ethyl  oxalate  yields  oxamid: 


CO.OC2H6  CO.NH2 

+     2NH3     =      | 
CO.OC2H5  CO.NH2 


+     2NH3     =      |  -f    2CH3.CH2OH. 

CO.] 


(2)   By  heating  the  neutral  ammonium  salt  of  the  corresponding 
acid.     Thus  ammonium  carbonate  yields  carbamid  : 


or/ONH4  nr/NH2     4-      9RO 

OC\ONH4  OC\NH2 

Carbamid  —  Urea  —  H2N.CO.NH2  —  exists  in  nature  in  the  urine 
of  the  mammalia,  and,  in  smaller  quantity,  in  the  excrement  of 
birds,  fishes  and  some  reptiles;  also  in  the  mammalian  blood,  chyle, 
lymph,  liver,  spleen,  lungs,  brain,  vitreous  and  aqueous  humors, 
saliva,  perspiration,  bile,  milk,  amniotic  and  allantoic  fluids,  and  in 
serous  fluids. 

Urea  is  formed  by  the  methods  given  above;  also,  (1)  as  a 
product  of  decomposition  of  uric  acid,  usually  by  oxidation.  Thus 
nitric  acid  oxidizes  uric  acid  to  urea  and  alloxan:  2C5H4N4Oa+ 
2H20+O2  =  2CON2H4+2C4H2N2O4.  (2)  By  the  hydrolysis  of  creatin. 
Thus  urea  and  sarcosin  are  formed  by  the  action  of  KHO  upon 
creatin:  C4H9N3O2+H2O  =CON2H4+C3H7NO2.  (3)  By  the  action 


NITROGEN    DERIVATIVES    OF    THE    PARAFFINS  349 

of  carbonyl  chlorid  upon  dry  ammonia:  COC^-f  2NH3=CON2H4-i- 
2HC1.  (4)  By  the  action  of  barium  hydroxid  upon  guanidin  (p.  335), 
or  upon  the  hexon  bases,  lysatin  and  arginin,  products  of  decomposi- 
tion of  the  proteins  (p.  499).  (5)  By  atomic  transposition  of  its 
isomere,  ammonium  isocyanate,  by  heat:  O : C : N.NH4==H2N.CO.NH2. 

Urea  crystallizes  from  its  aqueous  solution  in  long  rhombic  prisms 
or  needles.  It  is  colorless  and  odorless,  and  has  a  cooling  taste, 
somewhat  resembling  that  of  saltpeter.  It  is  neutral  in  reaction; 
soluble  in  one  part  of  water,  in  five  parts  of  cold  alcohol,  and  in 
one  part  of  boiling  alcohol,  soluble  in  amylic  alcohol,  nearly  in- 
soluble in  ether.  It  fuses  at  132°  (269.6°  F.). 

Heated  a  few  degrees  above  its  fusing  point,  urea  appears  to 
boil,  giving  off  ammonia  and  ammonium  carbonate,  and  finally  leaves 
a  dry,  solid  residue,  consisting  of  ammelid,  CeHg^Os,  cyanuric  acid, 
CaOaNsHs,  and  biuret,  C2H2N3Hs.  This  residue,  dissolved  in  water, 
gives  a  fine  red- violet  color  with  KHO  and  CuSO4  (Biuret  reaction). 
When  added  to  a  concentrated  solution  of  furfurole  and  hydrochloric 
acid,  solid  urea  or  urea  nitrate,  forms  a  yellow  solution,  changing 
in  color  to  green,  blue  and  intense  purple- violet.  After  a  time  the 
mixture  thickens  and  blackens  (Schiff  s  reaction). 

Dilute  aqueous  solutions  of  urea  are  not  decomposed  by  boiling; 
but  if  the  solution  be  concentrated,  or  the  boiling  prolonged,  or  the 
temperature  raised  above  100°,  the  urea  is  partly  decomposed  into 
CO2  and  NHs.  The  same  decomposition  takes  place  more  rapidly  and 
completely  under  pressure  at  140°  (234°  F.).  It  is  also  caused  by 
bacterial  action  and  by  a  urinary  enzym  (see  Urine). 

Urea  is  decomposed  into  carbon  dioxid,  water  and  nitrogen  by 
the  alkaline  hypochlorites  and  hypobromites,  by  chlorin  and  by 
nitrous  acid.  Strong  acids  and  alkalies  decompose  it  into  carbon 
dioxid  and  ammonia. 

Urea  forms  definite  compounds,  not  only  with  acids,  but  also 
with  certain  salts  and  oxids.  Urea  nitrate  —  H^N.CO.NEU.NOs  — 
forms,  in  white  crystals,  when  a  concentrated  solution  of  urea  is 
treated  with  nitric  acid  in  the  cold.  It  is  much  less  soluble  than 
urea,  especially  in  presence  of  an  excess  of  nitric  acid.  It  is  decom- 
posed by  evaporation  of  its  solutions.  Urea  oxalate — CO:  (NHa^CV 
€2  —  separates  as  a  fine,  crystalline  powder,  from  mixed  concentrated 
aqueous  solutions  of  urea  and  oxalic  acid.  Its  solution  may  be  evap- 
orated without  decomposition. 

When  solutions  containing  molecular  weights  of  urea  and  so- 
dium chlorid  are  evaporated,  prismatic  crystals,  containing  CON2H4, 
NaCl  -f-  IbO  are  obtained.  Urea  forms  several  compounds  with 
mercuric  oxid.  Of  these,  the  compound  (CON2H4)2,  4HgO,  con- 
taining 72  parts  of  HgO  for  10  parts  of  urea,  is  formed  as  a  white, 


350  MANUAL    OF    CHEMISTRY 

amorphous  precipitate  when  a  dilute  solution  of  mercuric  nitrate  is 
gradually  added  to  a  dilute,  alkaline  solution  of  urea,  and  the  excess 
of  acid  neutralized  from  time  to  time. 


THIOUREA   AND   THIOCAEBAMIC    ACIDS. 

The  thio-  compounds,  corresponding  to  carbamic  acid  (p.  346) 
and  to  urea,  in  which  oxygen  is  replaced  by  sulfur,  exist  either  in 
their  own  forms  or  in  their  derivatives.  Thus: 


0.r/ 
°'C\ 


SH  s  . 

NH2  S*\NH2  '\NH2  '\NH2 

Thiocarbamic  acid.      Sulfocarbamic  acid.   Dithiocarbamic  acid.  Thiourea. 


Thiocarbamic  acid  and  sulfocarbamic  acid  are  known  only  in 
their  esters.  Dithiocarbamic  acid  may  be  obtained  by  decomposition 
of  its  ammonium  salt,  which  is  produced  by  the  action  of  ammonia  in 

alcoholic  solution  upon  carbon  disulfid  :    CS2  +  2NH3  =  S:C<^|(^2H4) 

Similarly,  the  amin  salts  of  the  alkyl-dithiocarbamic  acids  are  formed 
by  the  action  of  the  primary  amins  upon  carbon  disulfid  (p.  343). 
Thiourea  may  be  obtained  by  the  action  of  heat  upon  ammonium 

isothiocyanate:  S:C:N(NH4)=S:C<3J122'  as  urea  is  obtained  from 
the  isocyanate  (p.  349).  It  is  also  formed  by  the  action  of  hydrogen 
sulfid  upon  cyanamid  (p.  344):  H2S  +  CN.NH2=  S:C^i22.  It  is 
decomposed  by  boiling  acids  or  alkalies  into  CO2,  NH3,  and  H2S. 
It  forms  salts,  and  alkyl,  phenyl  and  acidyl  derivatives  similar  to 
those  of  urea. 

COMPOUND   UREAS. 

These  compounds,  which  are  exceedingly  numerous,  may  be  con- 
sidered as  derived  from  urea  by  the  substitution  of  one  or  more 
alcoholic  or  acid  radicals  for  hydrogen  atoms. 

Those  containing  alcoholic  radicals,  alkyl    ureas,  such  as  ethyl 

urea,  CO\NH2C2H5,  are  obtained:  (1)  By  the  action  of  primary  or 
secondary  amins  upon  isocyanic  esters:  NH2.C2H5+O:C:N.C2H5  = 
CO:  (NH.C2H5)2.  (2)  By  heating  the  isocyanic  esters  with  water, 
the  amins  and  carbonic  acid  being  formed  as  intermediate  products: 
OC:N.C2H5+H2O  =  NH2.C2H5+CO2,  and  OC:N.C2H5+NH2.C2H5  = 
CO:(NH.C2H5)2. 

Those  containing  acid  radicals  have  received  the  distinctive  name 
of  ureids.  Of  these,  some  are  monureids,  derived  from  a  single 
molecule  of  urea,  others  diureids,  derived  from  two  molecules.  Some 


NITROGEN    DERIVATIVES    OF    THE    PARAFFINS  351 

of  the  monureids  are  open  chain  compounds,  but  the  most  important 
of  them,  and  all  the  diureids  are  cyclic  compounds.  Thus  there  are 

CH2OH 
two  ureids,  corresponding  to  glycollic  acid,    I          :  one,  hydantoi'c 

COOH 

acid,  an  open  chain  ureid:   CO  \NH!cH2 .COOH  5   ^he  °ther,  hydantoin, 

/NH.CH2 
a  cyclic  compound:   CO 

\NH.CO. 

The  monacidyl  monureids,  containing  a  single  acidyl,  are  formed 
by  the  action  of  acidyl  chlorids  or  anhydrids  upon  urea.  Thus 
acetyl-urea  is  obtained  with  acetyl  chlorid:  CH3.CO.Cl-hNH2.CO.- 
NH2  =  H2N.CO.NH  (CO.CH3)  +  HC1,  or  with  acetic  anhydrid  : 
(CO.CH3)2,O  +  2NH2.CO.NH2  =  2NH2.CO.NH(eO.CH3)  +  H2O. 
Mixed  ureids,  containing  an  alkyl  and  an  acidyl,  are  formed  in  like 
manner  from  alkyl -ureas.  Thus  methyl -urea  and  acetyl  chlorid  form 
methyl-acetyl-urea:  CH3.NH.CO.NH2  +  CH3.CO.C1  =  CH3.NH.CO.- 
NH(CO.CH3)-hHCl.  Such  mixed  ureids  are  also  formed  by  the 
action  of  bromin  and  potassium  hydroxid  upon  the  amids,  by  reac- 
tions comparable  with  those  which  give  rise  to  the  formation  of  the 
monamins  ( p .  327 ) .  Thus  methyl-acetyl-urea  is  formed  from  acetamid : 
2CH3.CO.NH2+Br2  +  2KHO  =  CH3.HN.CO.NH(CO.CH3)  +  2KBr+ 
2H2O. 

The  diacidyl-urei'ds  are  formed  by  the  action  of  phosgene  (car- 
bonyl  chlorid)  upon  the  amids.  Thus  acetamid  yields  diacetyl-urea: 
2CH3.CO.NH2  +  COC12  =  (CH3.CO)HN.CO.NH(CH3.CO)+  2HC1. 

Allophanic  Acid — CO<^NH2CQQjj —  the  simplest  of  the  open  chain 
monureids,  derived  from  carbonic  acid:  CO:(OH)2,  is  known  in  its 
esters  only.  The  corresponding  derivative  of  carbamic  acid:  CO\QH^ 

/NTT 

is  biuret,  CO<^NH*CO  NHa,  formed  by  heating  the  allophanic  esters 

with  ammonia,  or  by  heating  urea  to  150°-160°  (p.  349). 

/NH.CH2 

Glycolyl  Urea— Hydantoin  —  CO  I     ,   the   simplest  of  the 

\NH.CO 

cyclic  monureids,  is  formed  by  the  action  of  hydriodic  acid  upon 
allanto'fn  (p.  353),  or  upon  alloxanic  acid  (p.  353).  It  is  converted 
into  the  corresponding  open  chain  compound,  hydantoic,  or  glycol- 

uric  acid,  CO<^NH2CH2  CQQH,  by  heating  with  barium  hydroxid. 

Corresponding  to  hydantoin  are  a  number  of  substituted  hydan- 
toins  (its  superior  homologues),  constituted  by  substitution  of  alkyl 
groups  for  the  remaining  hydrogen.  They  differ  according  as  the 
substitution  is  in  the  CH2  group  (a) ;  in  the  NH  group  between  the 
CH2  and  CO  (j8);  or  in  the  NH  between  the  two  CO  groups  (y). 
The  ft  compounds  are  formed  by  heating  the  monoalkyl  ainido  acids 


352  MANUAL    OF    CHEMISTRY 

(p.  363)  with  urea.     Thus  urea  and  sarcosin  (p.  364)  yield  ft  methyl 
hydantom  : 

CH2(NH.CH3)  /MfPTT  \  PR 

CO(NH2)2     +       |  =     CO/£££^H      +    NH3     +     H20. 

/NH.CO 
Oxalyl  Urea—  Parabanic  acid—  CO  I    —  is  produced  by  oxi- 


dation  of  uric  acid,  or  of  alloxan  by  nitric  acid;  or  is  formed  synthet- 
ically by  the  action  of  phosphorus  oxychlorid  upon  a  mixture  of  urea 
and  oxalic  acid.  Its  salts  are  converted  into  oxalurates  by  water. 

Oxaluric  Acid  —  CO\NH?CO  .coOH  —  occurs  in  its  ammonium  salt 
in  the  urine  in  small  amount.  It  is  formed  from  oxalyl  urea  as 
indicated  above,  or  by  the  action  of  bromin,  or  by  heating  with 
calcium  carbonate.  The  free  acid  is  a  white,  crystalline  powder, 
sparingly  soluble  in  water.  It  is  readily  decomposed  into  urea  and 
oxalic  acid  by  heating  with  alkalies  or  even  with  water. 

Malonyl  Urea  —  Barbituric  acid  —  CO^NH.'co/CH2—  is  formed 
by  the  action  of  concentrated  sulfuric  acid  upon  alloxantin  (p.  354), 
and  is  produced  synthetically  by  the  action  of  phosphorus  oxy- 
chlorid upon  a  mixture  of  malonic  acid  and  urea  at  100°  (212°  F.). 

Nitromalonyl  Urea  —  CO<^H]co/CH-N°2  —  is  formed  by  the 
action  of  fuming  HNOa  on  malonyl  urea.  It  behaves  as  a  tribasic 
acid. 

Amidomalonyl  Urea—  CO<^H:co/CH-NH2—  is  formed  by  reduc- 
tion of  nitromalonyl  urea  by  hydriodic  acid.  It  yields  murexid  when 
boiled  with  ammonia;  and  is  converted  into  alloxan  by  nitrous  acid. 
It  is  the  parent  of  a  number  of  derivatives,  called  uramils,  consti- 
tuted by  substitution  of  alkyl  groups  for  the  remaining  hydrogen 
atoms. 

PseudouricAcid—  CO^NHlco/CH.NH.CO.NHs-which  differs  in 

composition  from  uric  acid  by  -j-H^O,  is  produced  as  its  ammonium 
salt,  by  heating  urea  and  amidomalonyl  urea  together  at  180°  (356° 
F.).  By  dehydration  by  heating  with  oxalic  acid  to  145°  (293°  F.) 
it  yields  uric  acid. 

Tartronyl  Urea—  Dialuric  acid—  CO<3J1;££/CH.OH—  is  pro- 
duced along  with  oxaluric  acid,  by  reduction  of  alloxan.  Nitrous 
acid  converts  it  into  allantoin. 

Mesoxalyl  Urea  —  Alloxan  —  COyNH]Co/CO  —  is  a  product  of  the 
limited  oxidation  of  uric  acid  or  of  alloxantin.  It  has  been  found  in 
the  intestinal  mucus  in  diarrhoea.  It  forms  prismatic  crystals,  readily 
soluble  in  water,  which  turn  red  in  air,  are  acid  in  reaction,  and  stain 


NITROGEN    DERIVATIVES    OF    THE    PARAFFINS 


353 


the  skin  red.  Reducing  agents  convert  it  into  alloxantin,  or  into  tar- 
tronyl  urea,  and  by  oxidation  it  yields  oxalyl  urea.  Heated  with 

barium  hydroxid  it  yields  alloxanic  acid :  CO<^NH2Co  CO  COOH 

Methyl  Uracyl— CO^H^a^^H— is  tne  methyl  derivative  of 

the  unknown  monure'id  uracyl,  produced  by  the  interaction  of  urea 

/NH2  CO.CH3  /NH.C(CH3) 

and  acetoacetic  ester:  CO  +1  =  CO  \  + 

\NH2  CH2.COO(C2H5)  \NH.CO rCH 

CH3.CH20H+H20.  It  is  formed  as  one  of  the  steps  in  a  synthesis 
of  uric  acid. 

Diurei'ds — may  be  considered  as  formed  by  the  fusion  of  two  mon- 
ureid molecules,  as  alloxantin  is  produced  by  the  fusion  of  two  alloxan 
molecules,  with  elimination  of  an  atom  of  oxygen.  Or  they  may  be 
regarded  as  formed  by  the  union  of  two  molecules  of  urea,  with  elimi- 
nation of  hydrogen,  and  the  introduction  of  a  group  of  equivalent 
valence,  except  in  the  case  of  diurea,  in  which  the  union  is  direct. 
Considered  in  this  latter  light,  the  diurei'ds  may  be  classified  into 
three  groups:  (1)  those  formed  by  fusion  of  two  molecules  of  urea, 
with  elimination  of  H2,  and  the  introduction  of  a  bivalent  group,  as 
carbonyl  diurea,  a  crystalline  substance,  formed  by  the  action  of 
phosgene  upon  urea  :  2H2N.CO.NH2+COCl2=(H2N.CO.NH)2CO+ 
2HC1;  (2)  those  formed  by  elimination  of  H3,  and  introduction  of  a 
trivalent  group,  as  in  allantoin,  (HN.CO.NH)  :CH.CO.(HN.CO.- 
NH2) ;  (3)  those  whose  formation  is  attended  with  elimination  of 
Ik.  This  group  maybe  further  subdivided  into:  (a)  those  formed 

by  direct  union  of  the  two  urea  remainders:  diurea,  CO<^NH'NH/CO, 
a  cyclic  derivative  of  hydrazin,  EbN.NEk  ;  (6)  those  in  which  the 
two  urea  remainders  are  symmetrically  attached  by  introduction  of  a 
quadrivalent  group,  as  alloxantin,  and  (c)  those  in  which  the  attach- 
ment is  unsym metrical,  as  in  uric  acid.  The  constitution  of  these 
several  compounds  is  illustrated  by  the  following  formulae: 


HN— C— NH    HN— CH— NH    HN-NH    HN— CO    OC-NH    HN— CO 


O 


OC 


CO      OC 


CO      OC    CO      OC 


O     OC      C-NH 

I      II     V 


H2N         NH2  HN-CO    NH2  HN— NH    HN— CO    OC— NH    HN— C-NH 

Carbonyl  Allantoin.  Diurea.  Alloxantin.  Uric  acid, 

diurea. 

Allantoi'n — C^eN^s — a  diure'id  derived  from  glyoxylic  acid  (p. 

297),  occurs  in  the  allantoic  fluid  of  the  cow,  in  the  urine  of  sucking 

calves,  of  dogs  and  cats  fed  on  meat,  of  children  during  the  first 

eight  days  of  life,  of  adults  after  administration  of  tannin,  and  of 

23 


354  MANUAL    OF    CHEMISTRY 

pregnant  women;  also  in  beet- juice.  It  is  formed  by  oxidizing  uric 
acid  by  lead  peroxid,  or  potassium  permanganate  in  alkaline  solution. 
Also  by  heating  together  urea  and  glyoxylic  acid  at  100°  (212°  F.), 
or,  similarly  from  urea  and  mesoxalic  acid  (p.  298).  It  crystallizes 
in  prisms,  tasteless,  neutral,  sparingly  soluble  in  cold  water,  readily 
soluble  in  hot  water  or  in  alcohol.  Warmed  with  barium  hydroxid, 

/NH.CH.OH. 
or   with   lead    peroxid,    it   forms   allanturic   acid:    CO 

Heated  with  alkalies  it  is  decomposed  into  oxalic  acid  and  am- 
monia. 

Alloxantin — CsH^N-tO? — is  formed  by  the  action  of  reducing  agents 
upon  alloxan,  or  by  the  oxidation  of  uric  acid.  It  forms  sparingly 
soluble  prisms,  which  turn  red  on  exposure  to  air.  It  is  derived  from 
alloxau  as  indicated  above. 

Murexid — is  the  ammonium  salt  of  the  unknown  purpuric  acid, 
CgHsNsOe,  derived  from  alloxan  tin  by  substitution  of  NH  for  O.  It 
is  a  purple  substance,  produced  by  heating  alloxantin  in  ammonia,  or 
by  evaporating  nitric  acid  on  uric  acid,  and  adding  ammonia  to  the 
residue  (murexid  reaction). 

URIC    ACID    AND    THE    XANTHIN    BASES. 

In  this  group  are  included  a  number  of  substances  of  great  physio- 
logical interest :  uric  acid,  xanthin,  hypoxanthin,  guanin,  and  their 
derivatives,  as  well  as  the  so-called  alkaloids  caffein  and  theobromin. 

Uric  Acid  —  Lithic  acid — Trioxypurin — CsI^NiOa —  occurs  in  the 
urine  of  man  and  of  the  carnivora,  in  combination,  chiefly  as  its 
disodic  salt;  in  the  urine  of  the  herbivora,  in  which  ordinarily  it  is 
replaced  by  hippuric  acid,  when,  in  early  life  and  during  starvation, 
they  are,  for  the  time  being,  practically  carnivora;  in  some  urinary 
calculi,  in  the  so-called  "chalky  deposits,"  or  "tophi,"  in  the  joints 
of  the  gouty;  very  abundantly  in  the  excretions  of  serpents,  tortoises, 
birds,  molluscs,  and  insects,  and  in  guano;  in  smaller  amount  in  the 
blood,  spleen,  lungs,  liver,  pancreas,  brain  and  muscular  fluid.  It  is 
best  obtained  from  guano  or  from  the  solid  urine  of  serpents,  which 
consists  almost  entirely  of  ammonium  urate.  It  is  formed  synthet- 
ically, as  described  below. 

When  pure,  uric  acid  crystallizes  in  small,  colorless-,  rhombic, 
rectangular  or  hexagonal  plates,  or  in  rectangular  prisms.  As  crys- 
tallized from  the  urine,  it  is  more  or  less  colored  by  the  urinary  pig- 
ments, and  the  angles  of  the  crystals  are  rounded  to  produce  lozenge 
shapes,  which  are  arranged  in  bundles,  crosses  or  daggers.  It  is 
almost  insoluble  in  water,  requiring  for  its  solution  1,900  parts  of 
boiling  water  and  15,000  parts  of  cold  water,  soluble  in  1,900  parts 


NITROGEN    DERIVATIVES    OF    THE    PARAFFINS  355 

of  a  2  per  cent,  solution  of  urea,  insoluble  in  alcohol  and  in  ether. 
Cold  HC1  dissolves  it  more  readily  than  IbO,  and  on  evaporation 
deposits  it  in  colorless,  rectangular  plates.  Its  aqueous  solution  is 
acid  to  test-paper,  but  tasteless  and  odorless.  It  also  dissolves 
unchanged  in  concentrated  EfeSOi,  and  is  deposited  from  the  solution 
on  dilution  with  water. 

Uric  acid  is  decomposed  by  heat  into  ammonia,  carbon  dioxid, 
urea  and  cyanuric  acid.  Heated  with  Cl  it  yields  cyanuric  acid 
and  HC1.  With  Cl,  Br  or  I,  at  the  ordinary  temperature,  it  forms 
oxalic  acid,  alloxan,  parabanic  acid  and  ammonium  cyanate.  It 
dissolves  in  cold  HNOs,  with  effervescence  and  formation  of  alloxan, 
alloxantin  and  urea;  with  hot  HNOa,  parabanic  acid  is  produced. 
A  yellow  or  red  residue  remains  when  HNOs  is  evaporated  on  uric 
acid;  this  assumes  a  fine  red -violet  or  purple  color  when  moistened, 
in  the  cold,  with  NILiHO,  NaHO  or  KHO  (murexid  reaction).  Uric 
acid  is  decomposed  by  sodium  hypobromite,  giving  off  47  per  cent, 
of  its  N  in  the  cold,  or  the  whole  when  heated.  It  reduces  the  salts 
of  copper  on  prolonged  boiling  in  alkaline  solution.  Nascent  hydro- 
gen reduces  it  to  xanthin  (Constitution,  see  p.  358). 

Uric  acid  is  a  weak  dibasic  acid.  The  monometallic  salts  are 
formed  by  dissolving  the  acid  in  solutions  of  the  metallic  carbonates, 
or  by  treating  solutions  of  the  dimetallic  salts  with  carbon  dioxid. 
The  dimetallic  salts  are  formed  by  dissolving  the  acid  in  solutions 
of  the  metallic  hydroxids,  free  from  carbonate.  Mono-ammonium 
urate,  CsHs^OsCNELi),  exists  in  the  solid  urines  of  the  lower  animals, 
and  in  urinary  sediments  and  calculi.  It  is  very  sparingly  soluble 
in  water.  Dipotassic  urate  is  alkaline  in  taste,  absorbs  C(>2  from 
the  air,  and  is  soluble  in  44  parts  of  cold  EkO.  Disodic  urate  forms 
nodular  masses,  soluble  in  77  parts  of  cold  water,  and  absorbs  C(>2 
from  the  air.  It  is  probably  in  this  form  of  combination  that  uric 
acid  exists  normally  in  the  urine.  Monsodic  urate  is  much  less 
soluble,  requiring  1,200  parts  of  water  for  its  solution.  It  exists, 
generally  amorphous,  in  urinary  sediments  (amorphous  urates)  and 
calculi,  and  in  the  arthritic  deposits  of  the  gouty,  sometimes  beauti- 
fully crystalline.  Monocalcic  urate,  soluble  in  603  parts  of  cold 
water,  also  occurs  occasionally  in  urinary  sediments  and  calculi,  and 
in  "chalk  stones."  Monolithic  urate,  CsHaN^sLi,  crystallizes  in 
needles,  soluble  in  60  parts  of  water  at  50°  (122°  F.),  or  in  368 
parts  at  19°  (68.2°  F.).  It  is  chiefly  with  a  view  to  the  formation 
of  this,  the  most  soluble  of  the  monometallic  urates,  that  the  salts 
of  lithium  are  given  to  patients  suffering  from  the  uric  acid  diathesis. 
Two  salts  of  uric  acid  with  organic  bases  are  still  more  soluble. 
Piperazin  urate  (p.  462)  dissolves  in  50  parts  of  water  at  17° 
(62. 6°  F.)  and  lysidin  urate  (p.  333)  in  6  parts  of  water. 


356  MANUAL    OF    CHEMISTRY 

The  Xanthin  Bases,  also  called  Alloxuric,  Purin,  or  Nuclein 
Bases,  form  a  series  of  which  uric  acid  is  the  most  highly  oxidized 
member: 

Uric  acid,  C5H4N4O3  Heteroxanthin,      C5H3(CH3)N4O2 


Xanthin, 
Hypoxanthin, 
Guanin, 

Adenin, 
Carnin, 

C5H4N4O2 
C5H4N4O 
C5H5N5O 

C5H5N5 
C7H8N403 

Paraxanthin, 
Theobromin, 
TheophylUn, 
Caffein, 
Epiguanin, 
Episarkin, 

C5H2(CH3).>N402 
C5H2(CH3)2N402 
C5H2(CH3)2N402 
C5H(CH3):)N402 
C5H4(CH3)N50 
C4H0N30(?) 

The  compounds  named  in  the  second  column  are  methyl  deriva- 
tives of  those  in  the  first  column.  The  xanthin  bases,  adenin, 
guanin,  hypoxanthin  and  xanthin,  are  products  of  decomposition  of 
the  nucleins,  which  are  themselves  produced  by  decomposition  of  the 
nucleoproteids,  important  constituents  of  nucleated  cells.  They  may, 
therefore,  be  considered  as  intermediate  products  of  oxidation  in 
the  formation  of  uric  acid,  and,  to  some  extent  at  least,  of  urea  in 
the  animal  bodjr. 

Xanthin — Xanthic  acid — Urous  acid — 2-6-Dioxypurin — C5H4N4O2 
—  occurs  in  a  rare  form  of  vesical  calculus;  in  the  pancreas,  spleen, 
liver,  thymus,  kidneys  and  brain,  and  in  the  melt  of  fishes.  It  is  a 
constant  constituent  of  the  urine  in  small  amount.  It  is  formed  by 
the  action  of  nitrous  acid  upon  guanin,  and  by  the  action  of  nascent 
hydrogen  upon  uric  acid. 

It  is  usually  amorphous,  but  may  form  rhombic  plates.  It  is 
very  sparingly  soluble  in  water,  insoluble  in  alcohol  or  ether,  readily 
soluble  in  alkalies.  Its  ammoniacal  solution  gives  a  gelatinous 
precipitate  with  silver  nitrate.  If  dissolved  in  nitric  acid  and  the 
solution  evaporated,  xanthin  leaves  a  yellow  residue,  which,  when 
moistened  with  KHO  solution,  turns  reddish-yellow,  and  violet-red 
when  heated.  Heated  to  100°  (212°  F.)  with  methyl  iodid,  it  is 
converted  into  theobromin.  When  chlorin  water  and  a  trace  of 
HNOa  are-  evaporated  with  xanthin.  and  the  residue  is  exposed  to 
ammonia,  it  assumes  a  red  or  purple  color  (Weidel's  reaction). 

Hypoxanthin  —  Sarkin  —  6-Oxypurin  —  CsEL^O  —  occurs  in  the 
same  situations  as  xanthin;  also  in  notable  quantity  in  the  blood 
and  urine  in  leukaemia,  and  in  the  melt  of  the  salmon  and  carp. 
It  also  occurs  in  numerous  seeds  and  pollen  of  plants,  and  is  pro- 
duced during  putrefaction  of  proteins.  It  is  a  product  of  the  action 
of  the  gastric  and  pancreatic  juices,  and  of  dilute  acids  upon  fibrin. 
It  is  produced  by  the  action  of  nitrous  acid  upon  adenin,  by  the 
action  of  sodium  amalgam  upon  uric  acid  or  xanthin,  and  by  the 
decomposition  of  some  nucleins  by  acids. 

It  crystallizes  in  small,  colorless  needles,  soluble  in  300  parts  of 
cold  water,  or  in  75  parts  of  boiling  water;  soluble  in  acids  and  in 


NITROGEN    DERIVATIVES    OF    THE    PARAFFINS  357 

alkalies.  Its  ammoniacal  solution  forms  a  precipitate  with  silver 
nitrate.  Nitrous  acid  oxidizes  it  to  xanthin.  It  does  not  give 
Weidel's  reaction.  When  acted  on  by  zinc  and  HC1,  and  then  treated 
with  excess  of  alkali,  it  forms  a  ruby -red  solution,  which  turns 
brown -red  (Kossel's  reaction). 

Guanin  —  2-Imido  -  6  -oxypurin  —  CsHsNsO  —  occurs  abundantly 
in  guano,  and  as  the  principal  constituent  of  the  excrement  of  spi- 
ders; in  less  amount  in  the  spleen,  liver,  pancreas  and  testicles;  in 
the  melt  of  the  salmon;  in  the  scales  and  swimming  bladders  of  cer- 
tain fish;  in  normal  urine  in  traces;  in  the  blood  in  leukaemia;  and 
in  the  young  leaves  and  pollen  of  certain  plants. 

It  is  a  white  or  yellowish,  amorphous,  tasteless  and  odorless 
powder;  almost  insoluble  in  water,  alcohol  and  ether;  readily  soluble 
in  acids  and  in  alkalies.  It  forms  crystalline  precipitates  with  silver 
nitrate  and  with  picric  acid.  It  gives  the  xanthin  reaction  with 
HNOs  and  KHO.  Nitrous  acid  oxidizes  it  to  xanthin.  Hydrochloric 
acid  and  potassium  chlorate  oxidize  it  to  guauidin  (p.  335),  oxalyl- 
urea  (p.  352)  and  €62.  It  does  not  respond  to  Weidel's  reaction. 

Adenin  —  6-Amido  -purin  —  CsHsNs  —  exists  widely  disseminated 
in  all  nucleated  cells,  most  abundantly  in  carp -melt  and  in  -the 
thymus  gland.  It  occurs  in  the  blood  and  urine  in  leukemia,  and 
also  exists  in  yeast  and  abundantly  in  tea  leaves. 

It  crystallizes  in  nacreous  plates,  or  in  long  needles,  containing 
3  Aq.,  which  they  lose  only  at  110°  (230°  F.),  although  they  sud- 
denly become  opaque  at  53°  (127.4°  F.),  a  property  characteristic  of 
adenin.  Very  soluble  in  hot  water,  it  requires  1,086  parts  of  cold 
water  for  its  solution.  It  is  insoluble  in  cold  alcohol,  ether  and 
chloroform;  readily  soluble  in  acids  and  alkalies,  with  which  it  forms 
compounds.  Its  solubility  in  ammonia  is  less  than  that  of  hypo- 
xanthin,  but  greater  than  that  of  guanin.  It  forms  crystalline, 
difficultly  soluble  compounds  with  silver  nitrate  and  with  picric  acid. 
It  is  not  reddened  by  warming  with  HNOs  and  moistening  the  residue 
with  alkali;  does  not  respond  to  Weidel's  reaction,  and  behaves 
like  hypoxanthin  towards  Kossel's  reaction.  Nitrous  acid  oxidizes 
it  to  hypoxanthin.  Heated  to  200°  (392°  F.)  with  HC1,  it  forms 
glycocoll,  ammonia,  formic  acid  and  carbon  dioxid.  Fused  with 
KHO  it  produces  potassium  cyan  id. 

Carnin  —  CyHgN^s  —  is  obtained  from  Liebig's  meat  extract,  and 
has  also  been  found  in  the  muscular  tissue  of  fish  and  of  frogs, 
and  in  the  urine.  It  is  isomeric  with  the  dimethyl -uric  acids.  It 
forms  chalky,  microscopic  crystals,  readily  soluble  in  hot  water, 
sparingly  soluble  in  cold  water,  insoluble  in  alcohol  and  ether.  It 
forms  compounds  with  acids  and  with  alkalies,  similar  to  those  of 
hypoxanthin.  Chlorin,  bromin  and  nitrous  acid  convert  it  into  hypo- 


358  MANUAL    OF    CHEMISTRY 

xanthin  by  elimination  of  the  elements  of  acetic  acid.  It  does  not 
respond  to  the  Weidel  reaction. 

Heteroxanthin  —  1 -Methyl- xanthin  —  CeHeN^  —  occurs  in  small 
quantity  in  the  urine,  accompanied  by  1-methyl-xanthin,  paraxanthin, 
or  1-7-dimethyl-xanthin,  epiguanin,  or  7-methyl-guanin,  and  epi- 
sarkin,  a  xanthin  base  of  undetermined  constitution.  With  the 
Weidel  reaction,  heteroxanthin,  1-methyl-xanthin  and  paraxanthin 
respond;  episarkin  and  epiguanin  do  not.  With  the  xanthin  reaction 
(HNOs  and  NaHO)  1-methyl-xanthin  gives  an  orange  color,  and 
epiguanin  a  red  color.  The  others  are  negative. 

Theobromin  —  3-7-dimethyl- xanthin  —  CyHgN^ — occurs  in  the 
seed  of  Theobroma  cacao  in  the  proportion  of  about  2  per  cent.  It 
is  a  crystalline  powder,  bitter  in  taste;  difficultly  soluble  in  water, 
alcohol,  ether,  and  chloroform;  soluble  in  acids,  with  which  it  forms 
salts;  soluble  in  NH4HO.  By  partial  demethylation  it  yields  hetero- 
xanthin. With  silver  nitrate  it  forms  a  crystalline  precipitate,  which, 
heated  with  methyl  iodid,  yields  caffein.  When  treated  with  chlorin 
water  and  gradually  evaporated,  it  leaves  a  red -brown  residue,  which 
turns  purple  with  NH4HO. 

Theophyllin  —  1-3-dimethy  I  -  xanthin  —  CTHgN^  —  occurs  in  tea 
extract,  and  is  formed  from  1-3-dimethyl-uric  acid. 

Caffein — Thein — Guaranin — 1-3-7-trimethy  I -xanthin — CsHioN^ 
— exists  in  coffee,  tea,  Paraguay  tea,  guarana,  and  other  plants,  and 
may  be  produced  from  1-3-7-trimethyl-uric  acid.  It  crystallizes  in 
long,  silky  needles;  faintly  bitter;  soluble  in  75  parts  H2O  at  15° 
(59°  F.);  less  soluble  in  alcohol  and  ether.  It  gives  the  same  reac- 
tion with  chlorin  water  and  NH4HO  as  theobromin.  With  HNO3, 
evaporation  and  addition  of  NH4HO,  it  gives  a  purple  color. 

Methyl-uric  Acids. — The  four  hydrogen  atoms  of  uric  acid  are 
replaceable  by  methyl  groups,  forming  three  mono-,  four  di-,  two  tri-, 
and  one  tetra- methyl  uric  acids.  These  compounds,  in  which  the 
methyls  are  attached  to  the  nitrogen  atoms,  are  produced  by  the 
action  of  methyl  iodid  upon  urates  or  upon  methyl -pseudouric  acids. 

Synthesis  and  Constitution  of  Uric  Acid  and  the  Xanthin 
Bases. — The  synthesis  of  uric  acid  has  been  accomplished  by  several 
methods,  starting  from  acetic  acid  and  urea,  through  monochloracetic 
acid  or  aceto- acetic  acid  (p.  298).  Two  of  the  simplest  are  the  fol- 
lowing :  (1)  Amido-acetic  acid  (p.  363),  when  heated  with  urea, 
forms  uric  acid  (disregarding  intermediate  products)  according  to 
the  equation:  CH2(NH2).COOH+3NH2.CO.NH2=C5H4N4O3+2H2- 
O-J-3NH3;  (2)  Malonic  acid  is  produced  from  mono-chloracetic  acid 
(p.  288).  From  this  malonyl  urea,  nitro-malonyl  urea,  amido- 
malonyl  urea,  pseudo- uric  acid  and  uric  acid  are  successively  obtained 
by  the  methods  given  on  p.  352: 


NITROGEN    DERIVATIVES    OF    THE    PARAFFINS 


359 


COOH 

CH2 

COOH 

Malonic  acid. 


HN— CO 

OC    CH2 

I      I 
HN— CO 

Malonyl  urea. 


HN— CO 

OC    CH.i 

I      I 
HN-CO 

Nitro-malonyl  urea. 


.(N02) 


HN-CO 

OC    CH.(NH2) 


HN-CO 

Amido-malonyl  urea. 


HN— CO 

I 


HN-CO 


CH.N-H 
CO 

HN— CO    H2N 
Pseudouric  acid. 


OC 


C.N-H 
CO 


HN— C.N-H 

Uric  acid. 


Uric  acid  and  the  xanthin  bases  are  considered  as  derivatives  of  a 
hypothetical  compound,  called  purin,  and  having  the  composition 
C5N4H4  (see  formula  below).  If  all  the  double  linkages  in  this 
formula  be  converted  into  single  ones  there  remain  three  bivalent 
positions,  2,  6,  and  8,  in  the  second  formula  below,  and  six  univalent 
positions  :  1,  3,  4,  5,  7,  and  9.  Or  if  the  double  linkage  between  4 
and  5  be  retained,  as  it  is  in  all  the  known  compounds  of  this  group, 
there  are  four  univalent  positions,  which  in  uric  acid  are  filled  by 
hydrogen  atoms,  while  the  bivalent  positions  are  occupied  by  oxygen 
atoms.  The  structural  formulae  of  the  members  of  the  xanthin  group, 
considered  as  derivatives  of  purin,  are  as  follows: 


N=C-H 


H 


-C     C-N-H 
II      II      \C_H 
II      II      /- 

N— C-N 

"Purin." 


2=C     C— N— 7 

3-N-C— N— 9 
4 


H-N— C=O 
0=C     C-N-H 


H-N— C-N-H 

Uric  acid  (Trioxypurin). 


H-N— C=O 
0=C    C  N-H 


\ 


C-H 


H-N- C-N 

Xanthin 
(2-6-Dioxypurin). 


(CH3)N— 0=0 

C-N-H 
II     \n 


1 

1 

-N 


H 

H 


H-N— C  N 

l-Methyl  xanthin. 


)=C     C-N  CH3 


I  M  v 

H-N— C-N 

Heteroxanthin 
(7-Methyl  xanthin). 


H-N-C=0 


H-C     C-N-H 


C-H 


N-C-N 

Hypoxanthin 
(6-Oxypurin). 


H-N— C=0 


N=C-NH2 


H-N=C     C-N-H         H-C     C-N-H 

|    I    >C-H      !!    I    \C-H 

H-N-C-N 

Guanin 
(2-Imido  -  6-oxypurin) . 


N— C-N 

Adenin 
(6-Amidopurin). 


360  MANUAL    OF    CHEMISTRY 

NITROGEN    DERIVATIVES    OP    ALCOHOLS,   ALDEHYDES,    AND    KETONES. 

Nitro  derivatives  of  the  alcohols,  aldehydes,  and  ketones  in  which 
the  NO2  is  substituted  for  OH  or  for  O,  such  as  CH3.CH2(N02),CH3.- 
CH(NO2)2  and  CH3.C(N02)2.CH3  are  mono-  or  din  itro-  paraffins 
(p.  325).  Besides  these,  nitro  alcohols  are  also  known,  in  which 
the  NO2  is  substituted  in  a  hydrocarbon  group,  e.  g.,  nitro  ethyl 
alcohol  CH2(NO2).CH2OH. 

Amido  alcohols,  such  as  amido  ethyl  alcohol,  or  oxethylamin, 
CH2OH.CH2(NH2),  may  also  be  considered  as  derived  from  the  gly- 
cols  by  substitution  of  NH2  for  OH.  These  are  the  oxyalkyl  bases, 
oxyamins,  or  hydramins,  among  which  are  cholin  and  neurin 
(p.  329). 

Aldehyde-ammonia  —  CH3.CH\^go  —  is  produced  by  the  action  of 

dry  NH3  upon  an  ethereal  solution  of  aldehyde.  It  is  a  crystalline 
solid,  soluble  in  water,  fusible  at  80°  (176°  F.).  The  corresponding 

compound   derivable    from    formic   aldehyde  :    H.CH<^NH2,    is    not 

known;  but  when  formaldehyde  and  ammonia  react,  hexamethylene- 
tetramin  (CH2)6N4,  is  produced:  6CH2O+  4NH3=(CH2)6N4-f  6H2O.. 
This  is  a  crystalline  solid,  very  soluble  in  water,  which  decomposes 
when  heated,  and  behaves  as  a  monacid  base.  It  is  used  as  a  diuretic 
and  solvent  of  uric  acid,  under  the  name  "formin." 

Amido  aldehydes,  such  as  amido  acetaldehyde,  CH2(NH2).CHO, 
are  also  known. 

The  aldoxims  are  derived  from  the  aldehydes  by  substitution  of 
the  oxim  group  (N.OH)"  (p.  335)  for  the  oxygen  of  the  aldehyde. 
Thus  acetoxim,  CH3.CH:N.OH,  corresponds  to  acetic  aldehyde, 
CH3.CHO.  They  are  formed  as  colorless  liquids,  miscible  with 
water,  by  the  action  of  hydroxylamin  upon  the  aldehyde:  H2N.OH-h 
CH3.CHO=CH3.CH.N.OH+H20.  The  aldoxims  are  hydrolized  into 
aldehyde  and  hydroxylamin  by  boiling  with  acids:  CH3.CH:N.OH+ 
H2O=HO.NH2+CH3.CHO.  They  form  nitrils  by  the  action  of 
acidyl  chlorids  or  anhydrids.  Thus  acetoxim  yields  acetonitril  and 
acetic  acid:  CH3.CH:NOH+CH3.COC1=CH3.CN+CH3.COOH-|-HC1, 
orCH3.CH:NOH+(CH3.CO)2O=CH3.CN+2CH3.COOH. 

Aldehyde  hydrazones  —  are  formed  by  the  action  of  hydrazins 
upon  aldehydes.  Thus  acetaldehyde  hydrazone  is  formed  from 
acetic  aldehyde  and  phenylhydrazin:CH3.CHO+H2N.NH.C6H5=CH3.- 
CH:N.NH.C6H5-1-H2O.  (See  also  p.  429). 

Acetonamins.  —  The  action  of  ammonia  upon  acetone  causes  a 
condensation  of  two  or  three  molecules  of  acetone,  with  formation  of 


-   PC) 

diacetonamin  :       3>     ^jC.NH2,  a  colorless  liquid;   and  triaceto- 


NITROGEN    DERIVATIVES    OF    THE    PARAFFINS  361 

namin:  OC^cH2'.c[cH3)2/NH'  a  crystalline  solid,  fusible  at  40° 
(104°  F.).  Amido-acetones,  or  amido-ketones,  such  as  CHs.CO.- 
CH2.NH2,  amidoacetone,  are  also  known. 

Ketoxims,  or  acetoxims,  are  compounds  corresponding  to  the 
aldoxims,  formed  by  the  substitution  of  the  oxim  group,  N.OH  for 
the  oxygen  of  the  acetone.  They  are  formed  by  the  action  of  hy- 
droxylamin  upon  an  alkaline  solution  of  the  acetone.  Thus  acetone 
yields  acetoxim:  CH3.CO.CH3+HO.N:H2=CH3.C(NOH).CH3+H2O, 
a  crystalline  solid,  fusible  at  60°  (140°  F.),  which,  by  the  action  of 
nascent  hydrogen,  is  converted  into  isopropylamin:  CH3.C(NOH).- 
CH3+2H2  =  (CH3)2.CH.NH2  +  H2O.  This  constitutes  a  general 
method  for  the  formation  of  the  primary  amins.  With  acidyl  chlorids 
they  do  not  form  nitrils  as  do  the  aldoxims,  but  the  acid  radical  re- 
places the  hydroxyl  hydrogen:  (CH3)2C:N.OH+CH3.COC1==(CH3)2- 
C:NO(CO.CH8)+HC1. 


NITROGEN  DERIVATIVES    OF  ACIDS — NITRO- ACIDS — AMIDO  ACIDS — 

LACTAMS. 

The  nitro-acids,  such  as  nitro-acetic  acid,  CH2(NO2).COOH,  are 
unstable  compounds,  usually  existing  only  in  their  esters. 

The  amido-acids  are  much  more  stable,  and  include  a  number  of 
substances  of  considerable  physiological  interest. 

The  amido-acids  are  derived  by  substitution  of  the  amido  group, 
NH2,  for  hydrogen  in  a  hydrocarbon  group  of  the  acid.  In  this  posi- 
tion the  attachment  of  the  amido  group  is  much  firmer  than  in  the 
primary  amids  (p.  345),  in  which  it  replaces  the  hydroxyl.  The 
amids  are  easily  hydrolized  by  boiling  water,  with  formation  of 
ammonium  salts,  while  the  amido-acids  suffer  no  decomposition 
under  like  treatment. 

From  the  pure  carboxylic  acids  (p.  277),  amic  acids  (p.  346), 
amids  (p.  345)  or  amido-acids  are  derivable  by  substitution  of  NH2 
for  OH  or  for  H  : 

CH3  CH3  CH2(NH2) 

COOH  CO(NH2)  COOH 

Acetic  acid.  Acetamid.  Amido-acetic  acid. 

COOH  CO(NH2)  CO(NH2)  COOH 

CH2  CH2  CH,.  CH(NH2) 


ir-  '  ' 


COOH  COO(C2H5)  CO(NH2)  COOH 

Malonic  acid.          Malonamic  ester.  Malonamid.       Amido-malonic  acid. 


362  MANUAL    OP    CHEMISTRY 

From  the  monocarboxylic  oxyacids  (p.  290),  oxyamids  are  de- 
rived by  substitution  of  NH2  for  OH  in  COOH;  amido- acids  of  the 
same  series  by  its  substitution  for  H  in  a  hydrocarbon  group  ;  and 
amido -acids  of  the  acetic  series  by  its  substitution  for  OH  in  a  CHOH 
or  a  CH2OH  group: 


CH3  CH2OH  CH3 

I  I  I 

CHOH  CH2  CHOH 

I  I 

COOH  CO(NH2) 

a  oxypropionic  /3  oxypropionic  Lactamid 

(lactic)  acid.  (hydracrylic)  acid.  (oxyamid). 


COO] 


CH2(NH2)  CH3  CH2(NH2) 

I  I  I 

CHOH  *CH(NH2)  CH2 

COOH  COOH  COOH 

Amido-lactic  a  amido-propionic  /3  amido-propionic 

acid.  acid.  acid. 

The  first  amido  -  acid  of  the  fatty  series,  amido-formic  acid, 
NH2.CO.OH,  is  carbamic  acid  (p.  346).  The  third  and  superior 
terms  of  the  series  form  place  isomeres,  according  to  the  position  of 
the  NH2  group,  corresponding  to  the  oxyacids  and  similarly  desig- 
nated (p.  290)  as  a,  /3,  y,  etc.,  or  1-,  2-,  3-,  etc.  The  fatty  amido- 
acids  are  also  known  as  glycocolls  or  alanins.  They  are  obtained  : 
(1)  By  the  action  of  ammonia  upon  the  monochloro  acids.  Thus 
amido- acetic  acid  is  obtained  from  monochloracetic  acid  :  CH2CL- 
COOH+NH3=CH2(NH2).COOH+HC1.  (2)  By  reduction  of  the 
nitro- acids.  Thus  nitroacetic  ester,  CH2(N02).COO.C2H5,  yields 
amido -acetic  acid.  (3)  By  the  action  of  nascent  hydrogen  upon  the 
cyan-fatty  acids:  CN.COOH+2H2=CH2(NH2).COOH. 

The  amido -acids  are  crystalline  solids,  most  of  which  are  sweet  in 
taste,  soluble  in  water,  insoluble  in  alcohol  or  in  ether,  neutral  in 
reaction.  As  they  contain  both  amido  and  carboxyl  groups,  they 
have  both  basic  and  acid  functions.  With  acids  they  form  ammonium 
salts.  They  form  stable  metallic  sal ts  -  with  bases,  but  their  esters 
are  unstable.  Stable  compounds  are,  however,  produced  by  the  re- 
placement of  their  amido  hydrogen,  either  by  acidyls  or  by  alkyls. 
The  acidyl  compounds,  such  as  acetyl  amido-acetic  acid,  CH2.NH 
(C2H3O).COOH,  are  formed  by  the  action  of  acidyl  chlorids  upon 
the  amido -acids;  and  the  alkyl  derivatives,  such  as  methyl  glyco- 
coll,  CH2.NH(CH3).COOH,  by  the  action  of  amins  upon  haloid  fatty 
acids.  On  dehydration  the  amido -acids  behave  like  the  oxyacids 
(pp.  291,  320),  which  are  also  both  basic  and  acid.  The  <*  acids  on 
dehydration  yield  cyclic  anhydrids,  corresponding  in  constitution  to 
the  lactids.  The  y  and  8  acids  yield  cyclic  esters,  called  lactams, 


NITROGEN    DERIVATIVES    OF    THE    PARAFFINS 


363 


corresponding  to  the  lactones.     The  resemblance  of  these  compounds 
is  shown  by  the  following  formulae  : 


CH2.NH2 
COOH 

Amido-acetic 
acid. 

CH2NH2 

CH2 

CH2 


COOH 

7  amido-butyric 
acid. 


CH2.NH.CO 
I  I 

CO.  NH.  CH2 

Glycocoll 
anhydrid. 

CH2NH 
CH2 
CH2 
CO 

7  butyro- 

lactam. 


CH2.OH 

COOH 

Glycollic 
acid. 

CH2.OH 

CH2 

CH2 

COOH 

oxy-butyric 
acid. 


CH2.COO 

COO  —  CH2 

Glycollid 
(lactid). 

CH2   i 

CH2 

CH2 

COO  J 

7  butyro- 
lactone. 


The  formation  of  the  lactams  is  another  instance  of  the  pro- 
duction of  closed  chain  from  open  chain  compounds  (pp.  320, 
334).  Delta  valerolactam  is  <*  keto-piperidin,  or  a  oxypiperidin 
(p.  461): 


CH2NH 


CH2 
I 
CH2 

CH2 


CO   J 

5  valerolactam. 


H2C 

I 

H2C 


\ 


CH2 

I 
CH2 


N 

H 

Piperidin. 


f 

C7 

H2C    /3    CH2 
H2C     a 

N 

H 

a  ketopiperidin. 


•wa-j.; 

Ao 


Amido-acetic  Acid — Glycocoll — Glycin — Glycolamic  acid — Gelatin 
CH2.NH2. COOH— was  first  obtained  by  the  action  of  H2SO4 
upon  gelatin.  It  is  also  formed  by  the  action  of  KHO  upon  glue; 
and,  synthetically,  by  the  methods  given  above  and  by  the  union  of 
formic  aldehyde,  hydrocyanic  acid  and  water:  H.CHO+HCN+H2O= 
CH2(NH2).COOH.  It  is  produced,  along  with  benzoic  acid,  in  the 
decomposition  of  hippuric  acid  (p.  425) ;  as  a  product  of  decomposition 
of  glycocholic  acid;  and  by  the  action  of  hydriodic  acid  upon  uric 
acid  (p.  358).  It  has  been  found  uncombined  only  in  the  muscle 
of  the  scallop. 

It  appears  as  large,  colorless,  transparent  crystals;  has  a  sweet 
taste;  fuses  at  170°  (338°  F.);  sparingly  soluble  in  cold  water; 
much  more  soluble  in  warm  water;  insoluble  in  absolute  alcohol 
and  in  ether. 

It  forms  crystalline  salts  with  acids,  which  are  decomposed  at  a 
boiling  temperature.  Nitric  acid  oxidizes  it  to  glycollic  acid.  Its 
acid  function  is  more  marked;  it  expels  carbonic  and  acetic  acids  from 


364  MANUAL    OF    CHEMISTRY 

calcium  carbonate  and  lead  acetate.  It  dissolves  cupric  hydroxid  in 
alkaline  solution,  and  there  is  no  reduction  on  boiling  the  solution; 
but  on  addition  of  alcohol  to  the  cold  solution,  blue  crystalline 
needles  of  copper  glycolamate  separate.  With  ferric  chlorid  it  gives 
an  intense  red  color,  which  is  discharged  by  acids,  and  restored  by 
ammonia.  With  phenol  and  sodium  hypochlorite  it  gives  a  blue 
color,  as  does  ammonia.  It  forms  esters  and  amids.  Its  methylic 
ester  is  isomeric  with  sarcosin.  Heated  under  pressure  with  benzoic 
acid  it  forms  hippuric  acid.  Fused  with  urea  it  forms  glycolylurea 
(p.  351)  and,  ultimately,  uric  acid. 

Methyl-glycocoll—  Sarcosin  —  CH2.NH(CH3)  .COOH  —  isomeric 
with  alanin  and  lactamid,  is  not  known  to  exist  as  such  in  animal 
nature,  but  it  may  be  obtained  from  creatin  (p.  336)  by  the  action  of 
barium  hydroxid: 

HN:C\N(CH3).CH2.COOH    +  H2°    =    CH2.NH(CH3).COOH  +  H2N.CO.NH2. 

It  is  formed  by  the  action  of  methylamin  upon  monochloracetic  acid : 
CH2C1.COOH+CH3.H2N=CH2.NH(CH3).COOH+HC1. 

It  crystallizes  in  colorless,  transparent  prisms  ;  very  soluble  in 
water;  sparingly  soluble  in  alcohol  and  ether.  Its  aqueous  solution 
is  not  acid,  and  has  a  sweetish  taste.  It  forms  salts  with  acids,  but  it 
is  not  known  to  form  metallic  salts.  It  unites  withcyanamid  to  form 
creatin  (p.  336)  ;  and  with  cyanogen  chlorid  to  form  methyl- 
hydantoin  (p.  352). 

Amido-propionic  Acids — Alanins — Two  are  known  :  «  alanin, 
CH3.CH(NH2).COOH,  formed  by  the  reduction  of  «  nitroso-propionic 
acid;  and  £  alanin,  CH2(NH2).CH2.COOH,  formed  either  by  the 
reduction  of  /?  nitroso-propionic  acid,  or  by  the  action  of  ammonia 
upon  /?  iodo-propionic  acid.  Neither  is  known  to  exist  in  nature. 

Amido-butyric  Acids — C4H9NO2 — and  Amido-valerianic  acids — 
C5HnNO2 — are  mainly  of  theoretic  interest.  Alpha  amido-n-valeri- 
anic  acid,  CH3.CH2.CH2.CH(NH2)  .COOH,  is  a  product  of  oxidation 
of  coniin.  Delta  amido-n-valerianic  acid — Butalanin,  CH2(NH2).- 
(CH2)3.COOH,  occurs  in  the  pancreas,  and  is  formed  as  a  product  of 
decomposition  of  fibrin  and  of  certain  proteids. 

Amido-caproic  Acids — Leucins. — Twenty -nine  isomeric  amido 
acids  are  derivable  from  the  seven  caproic  acids;  and  this  number  is 
still  further  increased  by  the  fact  that  in  many  of  these  the  introduc- 
tion of  the  amido  group  renders  a  carbon  atom  asymmetric  (see  for- 
mula of  o.  amido-propionic  acid,  p.  362).  The  leucin,  which  is  of 
physiological  interest  as  a  product  of  decomposition  of  the  proteins,  is 
the  inactive  «  amido-isobutyl-acetic  acid,  (CH3)2:CH.CH2.*CH- 
(NH2).COOH,  as  is  demonstrated  by  its  synthetic  formation  from 


NITROGEN    DERIVATIVES    OF    THE    PARAFFINS  365 

isovaleric  aldehyde,  (CHa^rCH.CIb.CHO.  The  corresponding  dextro- 
acid  has  been  obtained  by  the  action  of  Penicillium  glaucum  upon  the 
inactive  acid  ;  and  the  laevo-  acid,  known  as  "vegetable  leucin" 
from  the  vegetable  globulin,  conglutin. 

"Animal  leucin"  is  produced,  accompanied  by  tyrosin  (p.  424), 
in  the  decomposition  of  proteins  by  boiling  with  dilute  acids  or  alka- 
lies, by  fusion  with  caustic  alkalies,  by  putrefaction,  and  by  trypsin 
digestion.  It  appears  to  exist  also  as  a  normal  constituent  of  the 
pancreas,  spleen,  thymus,  lymphatic  and  salivary  glands,  liver  and 
kidneys.  Pathologically  the  quantity  of  leucin  is  much  increased  in 
the  liver  in  diseases  of  that  organ,  in  typhus  and  in  variola;  in  the 
bile  in  typhus;  in  the  blood  in  leukaemia,  and  in  j^ellow  atrophy  of 
the  liver;  in  the  urine  in  yellow  atrophy  of  the  liver,  in  typhus,  in 
variola,  and  in  phosphorus  poisoning;  in  choleraic  discharges  from 
the  intestine;  in  pus;  in  the  fluids  of  dropsy  and  of  atheromatous 
cysts. 

Leucin  crystallizes  from  alcohol  in  soft,  pearly  plates,  lighter  than 
water,  and  somewhat  resembling  cholesterol;  sometimes  in  rounded 
masses  of  closely  grouped,  radiating  needles.  Pure  leucin  is  spar- 
ingly soluble  in  water,  almost  insoluble  in  alcohol  and  ether,  but 
readily  soluble  in  hot  water  or  alcohol.  When  impure  it  is  more 
soluble.  It  is  odorless  and  tasteless,  and  its  solutions  are  neutral. 
It  dissolves  readily  in  acids  and  alkalies,  forming  crystalline  com- 
pounds with  the  former.  It  fuses  and  sublimes  at  170°  (338°  F.) 
without  decomposition,  but  at  a  slightly  higher  temperature  is  decom- 
posed into  amylamin  and  carbon  dioxid. 

When  heated  with  hydriodic  acid  under  pressure  the  leucins  are 
decomposed  into  ammonia  and  the  corresponding  caproic  acids.  By 
nitrous  acid  they  are  oxidized  to  the  corresponding  oxycaproic,  or 
leucic  acids,  CeH^Oa  (p.  293),  with  elimination  of  water  and  of 
nitrogen.  •  Hot  solutions  of  leucin  form  precipitates  with  hot  solu- 
tions of  cupric  acetate.  They  dissolve  cupric  hydroxid,  but  do  not 
reduce  it  on  boiling.  When  boiled  with  solution  of  neutral  lead  ace- 
tate and  carefully  neutralized  with  ammonia,  they  deposit  brilliant 
crystals  of  a  compound  of  leucin  and  lead  oxid.  When  HNOa  is 
slowly  evaporated  in  contact  with  leucin  on  platinum  foil  a  colorless 
residue  remains,  which,  when  warmed  with  NaHO  solution,  turns 
yellow  or  brown,  and  on  further  concentration,  forms  oily  drops, 
which  do  not  adhere  to  the  platinum  (Scherer's  reaction).  Solution 
of  leucin,  when  heated  with  solution  of  mercurous  nitrate,  liberates 
metallic  mercury  (Hofmeister's  reaction). 

Diamido-fatty  acids  have  been  obtained  as  products  of  decompo- 
sition of  proteins.  Diamido-acetic  acid,  CH(NH2)2.COOH,  is  pro- 
duced by  boiling  proteins  with  tin  and  HC1.  Diamido-propionic 


366  MANUAL    OF    CHEMISTRY 

acid,  CH2(NH2).CH(NH2).COOH,  has  been  obtained  synthetically 
from  a  /3  dibromo  -  propionic  acid.  Ornithin,  a  product  of  decomposition 
of  ornithuric  acid,  a  substance  eliminated  by  birds  after  administra- 
tion of  benzoic  acid,  is  probably  a  diamido-valerianic  acid,  CJIr 
(NH2)2.COOH.  Lysin,  one  of  the  hexon  bases,  produced  in  tryptic 
digestion,  and  by  decomposition  of  proteins  and  of  protamins,  is  a 
diamido-caproic  acid,  C5H9(NH2)2.COOH.  (See  Proteins.) 

Amido-dicarboxylic  Acids  —  Amido-malonic  acid,  COOH.CH- 
(NH2).COOH,  is  a  synthetic  product  which  decomposes  readily  into 
amido- acetic  acid  and  C02. 

Amido-succinic  Acid— Aspartic  acid— COOH.CH*(NH2).CH2.- 
COOH — exists  in  three  optical  modifications,  of  which  the  laevo-acid  is 
the  most  important.  It  is  produced  during  tryptic  digestion  of  proteins, 
and  is  a  product  of  their  decomposition  by  dilute  acids.  It  is  present 
in  beet-juice  vianesse,  and  is  obtained  from  many  vegetable  sub- 
stances as  a  product  of  decomposition  of  its  amid,  asparagin,  CO- 
(NH2).CH(NH2).CH2.COOH.  It  crystallizes  in  rhombic  prisms, 
difficultly  soluble  in  cold  water,  readily  soluble  in  hot  water.  Nitrous 
acid  converts  it  into  1- malic  acid.  It  forms  a  crystalline  compound 
with  cupric  oxid,  which  is  soluble  in  hot  water,  but  almost  insoluble 
in  cold  water. 

Asparagins — Amido-succinic  Amids — The  dextro-  and  lasvo- 
modifications  occur  together  in  many  plants,  in  asparagus,  and  in  the 
sprouts  of  peas,  bean  and  vetches.  Laevo  -  asparagin ,  which  predomi- 
nates in  nature,  crystallizes  in  rhombic  prisms,  sparingly  soluble  in 
water,  odorless,  faintly  nauseous  in  taste,  faintly  acid  in  reaction. 
It  enters  into  unstable  combination  with  both  acids  and  bases. 
Heated  with  acids  or  alkalies,  it  yields  aspartic  acid  and  ammonia. 
Nitrous  acid  oxidizes  it  to  malic  acid,  with  elimination  of  N  and 
H2O. 

Amido-glutaric  Acid— Glutaminic  acid— COOH.CH*(NH2)  .CH2.- 
CH2,COOH. — The  dextro -acid  accompanies  aspartic  acid  as  a  product 
of  decomposition  of  proteins  and  in  the  vegetables  mentioned.  It 
crystallizes  in  rhombic  octahedra,  soluble  in  hot  water,  insoluble  in 
alcohol  and  in  ether.  While  the  dextro -acid  is  produced  by  decom- 
posing proteins  by  acids,  the  inactive  acid  is  formed  when  barium 
hydroxid  is  the  decomposing  agent.  It  forms  a  crystalline  compound 
with  HC1,  which  is  almost  insoluble  in  the  concentrated  acid.  It 
forms  a  crystalline  copper  salt. 

Amido-thioacids. — Two  amido  derivatives  of  thioacids  are  of 
physiological  interest : 

Amido  -  isethionic  Acid — Amido  ethyl-sulfonic  acid — Taurin  — 
CH2.NH2 

— the  amido  derivative  of  isethionic,  or  oxyethyl  sulfonic 
CH2.S03H 


PHOSPHORUS,    ANTIMONY    AND    ARSENIC    DERIVATIVES        367 

CH2.OH 

acid  (p.  322),    I  ,  occurs  in  combination  with  cholic  acid  as 

CH2.SO3H 

taurocholic  acid  in  the  bile  (p.  527),  from  which  it  may  be  obtained 
by  decomposition  by  HC1.  It  also  exists  in  the  intestine,  faeces, 
muscle,  blood,  liver,  kidneys,  and  lungs.  "  Taurin  appears  in  the  urine 
partly  in  its  own  form,  and  partly  combined  with  carbamic  acid  as 
tauro-carbamic  acid:  NH2.CO.NH.CH2.CH2.SO3H.  It  is  formed 
synthetically  by  heating  together  chlorethyl  sulfonic  acid  and  am- 
monia : 

CHo.Cl  CH2.NH2 

|  +      NH3      =       |  +      HC1. 

CH2.SO3H  CH2.SO3H 

Taurin  crystallizes  in  large,  oblique  rhombic  prisms,  soluble  in  water, 
insoluble  in  alcohol  and  in  ether.  Boiled  with  strong  alkalies,  it 
yields  acetic  acid  and  sulfur  dioxid.  It  forms  compounds  with  me- 
tallic oxids.  That  of  mercury  is  formed  by  boiling  taurin  solution 
with  freshly  precipitated  mercuric  oxid,  and  is  white  and  insoluble. 
Nitrous  acid  oxidizes  it  to  isethionic  acid,  with  elimination  of  N  and 
H2O.  It  behaves  both  as  a  base  and  as  an  acid. 

Amido-thiolactic  Acid—  CH3.C(SH)  (NH2).COOH—  is  the  prob- 
able constitution  of  cystem,  a  product  of  decomposition  of  cystin, 
which  is  probably  dithio-diamido-dilactic  acid, 


p*/COOH 

CH3/          -2...2.C 


Cystin  occurs  in  the  urine  and  in  urinary  sediments  and  calculi. 
It  crystallizes  in  thin,  colorless,  six-sided  plates,  insoluble  in  water, 
alcohol,  ether,  or  acetic  acid,  soluble  in  mineral  acids  and  in  alkalies. 
It  is  strongly  laBvogyrous.  Nascent  hydrogen  converts  it  into  cystem. 
Its  solution  in  NaHO  forms  a  precipitate  with  benzoyl  chlorid. 
Heated  with  HNO3  and  evaporated,  it  leaves  a  red  -brown  residue 
which  does  not  give  the  murexid  reaction.  Its  HC1  solution  forms 
an  insoluble  precipitate  with  HgCl2. 


PHOSPHORUS,  ANTIMONY,  AND    ARSENIC   DERIVATIVES. 

Many  organic  compounds,  similar  to  those  containing  nitrogen,  in 
which  that  element  is  replaced  by  phosphorus,  antimony,  or  arsenic, 
are  known.  Of  these  only  a  few  arsenic  derivatives  require  mention. 

Dimethyl  Arsin — (CHshHAs — corresponding  to  dimethyl  amin, 
(CHahHN,  is  a  colorless  liquid,  having  an  intensely  disagreeable 
odor,  which  ignites  spontaneously  in  air.  It  may  be  considered  as 
the  hydrid  of  a  radical,  (CHshAs,  which,  from  the  disagreeable  odor 


368  MANUAL    OF    CHEMISTRY 

and  intensely  poisonous  action  of  all  of  its  compounds,  has  received 
the  name  cacodyl  (*a*os=evil).  As  the  amins  are  considered  as 
derived  from  ammonia  by  substitution  of  alkyl  groups  for  the 
hydrogen,  so  the  compounds  of  which  this  is  a  type  are  derived  from 
the  corresponding  hydrogen  -compounds  of  phosphorus,  antimony,  and 
arsenic,  and  are  called  phosphins,  stibins,  and  arsins. 

The  parent  substance  of  the  arseno- organic  compounds  is  a 
fuming,  foul -smelling  liquid,  obtained  by  distilling  a  mixture  of 
arsenic  trioxid  and  potassium  acetate,  and  called  fuming  liquid  of 
Cadet.  The  principal  constituent  of  this  is  cacodyl  oxid,  or  alkarsin, 

(CH^As/0'  a  liquid  which  boils  at  120°  (248°  F.),  insoluble  in  water, 
soluble  in  alcohol  and  in  ether.  Cacodyl,  or  dicacodyl,  (CHa)2  As.- 
As(CH3)2  is  a  colorless,  insoluble  liquid,  which  boils  at  170°(338°F.), 
and  ignites  spontaneously  in  air.  Cacodyl  and  all  of  its  compounds 
are  exceedingly  poisonous,  especially  the  cyanid,  an  ethereal,  volatile 
liquid  the  presence  of  whose  vapor  in  air,  even  in  minute  traces,  pro- 
duces symptoms  referable  both  to  arsenic  and  to  cyanogen.  Prob- 
ably minute  quantities  of  arsins  are  formed  during  the  putrefaction 
of  cadavers  embalmed  with  arsenical  liquids. 


UNSATURATED    ALIPHATIC   COMPOUNDS. 

In  this  class  are  included  all  open  chain  carbon  compounds  in 
which  two  carbon  atoms  exchange  more  than  one  valence  (p.  224). 
As  the  saturated  compounds  consist  of  the  members  of  the  first, 
or  methane,  series  of  hydrocarbons  and  their  derivatives,  so  the  un- 
saturated  compounds  are  the  remaining  series  of  open  chain  hydro- 
carbons and  their  unsaturated  derivatives  (p.  229). 


HYDROCARBONS,    ETHENE,    OR    OLEFIN    SERIES. 

The  members  of  this  series  contain  two  atoms  of  carbon  less  than 
the  corresponding  terms  of  the  methane  series.  They  may  be  modi- 
fied by  addition,  behaving  as  bivalent  radicals,  as  well  as  by  substitu- 
tion. Their  "  Geneva  "  names  terminate  in  ene. 

Ethene — Ethylene — Olefiant  gas — Olefin — Elayl — Heavy  carbu- 
retted  hydrogen — CH2:CH2 — is  formed  by  the  dry  distillation  of  fats, 
resins,  wood,  and  coal,  and  is  a  valuable  constituent  of  illuminating 
gas. 

It  is  formed  synthetically:  (1)  By  heating  a  mixture  of  alcohol, 
H2SO4  and  sand.  In  this  reaction  ethyl -sulf uric  acid  is  formed  and 
decomposed:  C2H5.HSO4=H2SO4+CH2:CH2.  (2)  By  the  action  of 
caustic  potash  upon  ethyl  bromid:  CH3.CH2Br+KHO=KBr+H204- 


UNSATURATED    ALIPHATIC    COMPOUNDS  369 

(3)  By  heating  together  acetylene  and  hydrogen,  or  by 
the  action  of  nascent  hydrogen  upon  copper  acetylid  :  CH:CH-|-H2= 
CH2:  CH2,  or  C2Cu2+2H2=CH2:  CH2+2Cu.  (4)  By  heating  methylene 
iodid  with  copper:  2CH2I2+2Cu=CH2:CH2+2CuI2.  (5)  By  the 
action  of  sodium  or  of  zinc  upon  ethylene  chlorid  or  bromid:  CH2CL- 
CH2CH-Na2=CH2:CH2+2NaCl,  or  CH2Br.CH2Br+Zn=CH2:CH2+ 
ZnBr2. 

It  is  a  colorless  gas,  tasteless,  has  a  faint  odor  of  salt  water,  spar- 
ingly soluble  in  water.  Its  critical  temperature  is  13°  (55.4°  F.) ;  its 
critical  pressure  60  atmospheres.  It  boils  at  — 105°  ( — 157°  F.). 

It  burns  with  luminous  flame,  and  forms  explosive  mixtures  with 
air.  By  long  contact  with  a  red-hot  surface  it  is  decomposed  into 
acetylene,  methane,  ethane,  a  tarry  product,  and  carbon.  It  unites 
with  hydrogen  to  form  ethane,  C2He;  with  oxygen  it  unites  explo- 
sively on  approach  of  flame,  to  form  carbon  dioxid  and  water.  It 
combines  with  hydrobromic  and  hydriodic  acids  to  form  ethyl  bromid, 
C2H5Br,  and  ethyl  iodid,  C2HsI.  It  combines  with  sulfuric  acid  to 
form  ethyl -sulf uric  acid:  CH2  :CH2+H2SO4=C2H5.HSO4.  Mixtures 
of  ethene  and  chlorin  explode,  with  copious  deposition  of  carbon,  on 
approach  of  flame.  In  diffuse  daylight  they  unite  slowly,  with  sepa- 
ration of  an  oily  liquid,  ethylene  chlorid,  or  dutch  liquid,  CH2C1.- 
CH2C1,  to  whose  formation  the  name  "olefiant  gas"  is  due  (p.  316). 
The  same  compound  is  formed  when  ethene  is  passed  through  a  mix- 
ture of  MuO2,  NaCl,  H2SO4,  and  H2O.  When  passed  through  alka- 
line solution  of  potassium  permanganate,  it  is  oxidized  to  oxalic  acid 
and  water:  2CH2:CH2+5O2=2COOH.COOH-f-2H2O;  or,  by  careful 
oxidation  by  dilute  solution  of  the  same  agent,  it  forms  ethene  glycol: 
2CH2:CH2+2H2O+O2=2CH2OH.CH2OH  (p.  252). 

When  inhaled,  diluted  with  air,  ethene  produces  effects  somewhat 
similar  to  those  of  nitrous  oxid. 

Two  groupingsof(C2H4)//are  possible,— CH2.CH2,—  andCH3.CH=, 
the  former  produced  by  the  breaking  of  the  double  bond  between  the 
carbon  atoms  in  ethene,  the  latter  by  double  substitution  in  ethane. 
Compounds  containing  the  grouping — CH2.CH2 — are  designated  as 
ethylene  or  ethene  compounds,  e.  g.,  ethylene  chlorid,  C1CH2.- 
CH2C1,  b.  p.  84°,  those  containing  the  grouping  CH3.CH=  are  called 
ethidene  or  ethylidene  compounds,  e.  g.,  ethidene  chlorid,  CHs.- 
CHC12,  b.  p.  53°. 

Homologues  of  Ethene.— The  superior  homologues  of  ethene 
exist  in  coal  gas  and  coal  tar.  They  are  formed  by  the  methods  1 
and  2,  used  for  the  preparation  of  ethene,  but  starting  from  the  cor- 
responding superior  monoatomic  alcohol.  The  lower  terms  are  gas- 
eous, the  higher  liquid  at  the  ordinary  temperature.  They  undergo 
reactions  similar  to  those  of  ethene,  and  in  addition,  readily  poly- 
24 


370  MANUAL    OF    CHEMISTRY 

merize  under  the  influence  of  sulfuric  acid,  zinc  chlorid  and  other 
substances. 

Trimethyl-ethylene  — Pentene — Amylene  — Valerene — (CHs)2:  C :  - 
CH.CHs— is  a  colorless,  mobile  liquid,  boiling  at  39°  (102.2°  F.), 
obtained  by  heating  alcohol  with  a  concentrated  solution  of  zinc 
chlorid.  It  is  used  as  an  anesthetic,  and  in  the  preparation  of  ter- 
tiary amylic  alcohol  (p.  251). 


ETHINE,    OR    ACETYLENE    SERIES. 

Acetylene — Ethine — HC  :  CH — exists  in  coal  gas,  and  is  formed  in 
the  decomposition,  by  heat  or  otherwise,  of  many  organic  substances. 
It  is  formed:  (1)  By  passing  an  electric  arc  in  an  atmosphere  of 
hydrogen:  2C+H2=CH  :CH.  This  is  the  only  known  synthesis  of  a 
hydrocarbon  directly  from  the  elements.  (2)  By  the  action  of  water 
upon  calcium  carbid  :  C2Ca+2H2O=HC  ;  CH+CaH2O2.  This  method 
is  used  industrially  for  the  preparation  of  acetylene  for  use  as  an  illu- 
minating gas.  (3)  By  heating  chloroform,  bromoform  or  iodoform 
with  sodium,  copper,  silver  or  zinc :  2CHCl3-f3Na2=6NaCl+HC  i  CH. 
(4)  By  heating  ethylene  bromid  with  caustic  potash.  The  reaction 
occurs  in  two  phases,  vinyl  bromid  being  formed  as  an  intermediate 
product :  CH2Br.CH2Br  +  KHO  =  CHBr:CH2  +  KBr  +  H2O,  and 
CHBr:CH2+KHO=CH ':  CH-f  KBr+H2O. 

Acetylene  is  a  colorless  gas,  rather  soluble  in  water,  having  a  pe- 
culiar, disagreeable  odor,  that  which  is  observed  when  a  Bunsen 
burner  burns  within  the  tube.  It  is  liquefied  by  a  pressure  of  48 
atmospheres  at  0°  (32°  F.).  It  forms  explosive  mixtures  with  air  or 
oxygen.  In  contact  with  a  red-hot  surface,  and  in  absence  of  air,  it 
polymerizes  to  benzene  3C2H2=C6H6,  an  action  which  accounts  for 
the  presence  of  benzene  in  gas  tar,  and  which  is  of  great  interest  in 
connection  with  the  relations  between  the  open  chain  and  the  closed 
compounds  (p.  378).  Nascent  hydrogen  converts  acetylene  into 
ethene,  C2H4,  and  then  into  ethane,  C2He.  Under  the  influence  of  the 
electric  discharge,  it  combines  with  nitrogen  to  form  hydrocyanic 
acid:  C2H2+N2=2CNH.  It  combines  with  HC1  and  with  HI  to 
form  ethidene  chlorid,  CH3.CHC12,  or  iodid,  CH3.CHI2.  Mixed 
with  chlorin  it  detonates  violently  in  diffuse  daylight.  The  hydro- 
gen atoms  of  acetylene  may  be  replaced  by  metals  to  form  acety- 
lids,  or  carbids.  Sodium  and  calcium  acetylids  are  stable  at 
high  temperatures,  but  are  decomposed  by  water  with  formation 
of  acetylene.  Silver  and  copper  acetylids  are  highly  explo- 
sive when  dry,  and  explosions  which  have  occurred  when  illumi- 
nating gas  was  in  contact  with  brass  or  copper  were  probably  due 
to  the  formation  of  the  latter.  The  formation  of  copper  acety- 


UNSATUEATED    ALIPHATIC    COMPOUNDS  371 

lid,  which  separates  as  a  blood -red  precipitate  when  acetylene  is 
conducted  through  a  solution  of  cuprous  chlorid,  is  utilized  as  a  test 
for  the  presence  of  acetylene.  Acetylene  mercuric  chlorid,  C2- 
(HgCl)2,  separates  as  a  non- explosive,  white  precipitate  when  acety- 
lene is  passed  through  a  solution  of  mercuric  chlorid. 


DIOLEPIN    AND    SUPERIOR    SERIES. 

The  diolefins  are  isomeric  with  the  hydrocarbons  of  the  acetylene 
series,  containing  two  double  linkages,  in  place  of  one  triple  linkage. 
Thus  allene,  or  allylene,  CH2:C:CH2,  is  isomeric  with  propylene, 
CH  ;  C.CHs.  Higher  series,  p.  229. 

Olefin  Terpenes  —  Terpenogens.  —  While  most  essential  oils  and 
other  aromatic  substances  are  closed  chain  compounds,  some  ethereal 
oils  contain  or  yield  unsaturated,  open  chain  hydrocarbons,  alcohols, 
aldehydes  or  acids.  Among  the  hydrocarbons  are  myrcene,  and  an- 
hydrogeraniol,  CioHie,  the  former  obtained  from  bay  -oil,  the  latter 
from  oil  of  geranium.  Isoprene,  a  product  of  distillation  of  caout- 
chouc, a  liquid  boiling  at  37°  (98.6°  F.),  is  probably  methyl-di  vinyl, 


UNSATURATED    HALOGEN    DERIVATIVES. 

These  cannot  be  formed  directly,  because  addition  products,  such  as 
ethylene  chlorid,  are  formed  in  preference:  CH2:CH2+C12==CH2C1.- 
CH2C1.  But,  by  indirect  methods,  halogen  derivatives  of  both  ole- 
fins  and  acetylenes  have  been  obtained,  such  as  vinyl  chlorid,  CH2:- 
CHC1,  and  vinyl  bromid,  CEbrCHBr.  The  propylene  derivatives  are 
a  CHs.CH.'CHCl,  ft  CH3.CC1:CH2,  or  y  CH2C1.CH:CH2,  according  to 
the  position  of  the  substitution. 

The  y  derivatives  are  the  allyl  haloids,  corresponding  to  allylic 
alcohol.  Of  these,  allyl  iodid,  CH2I.CH:CH2,  is  frequently  used 
as  a  reagent.  It  is  prepared  by  the  action  of  hydriodic  acid,  or  of 
iodin  and  phosphorus  upon  glycerol. 

Corresponding  to  allyl  iodid,  but  referable  to  propylene,  are 
propargyl  iodid  and  chlorid,  CH:C.CH2I  and  CH:C.CH2C1,  the 
latter  produced  by  the  action  of  phosphorus  trichlorid  upon  pro- 
pargyl alcohol  (p.  372). 

UNSATURATED  OXIDATION  PRODUCTS  OP  UNSATURATED  HYDROCARBONS 

Like  the  paraffins,  the  olefins,  acetylenes,  diolefins,  etc.,  yield 
alcohols,  aldehydes,  ketones,  acids,  oxids  and  esters  (p.  237). 

Vinyl  Alcohol—  CH2:CH.  OH—  the  simplest  of  the  olef  in  alcohols, 


372  MANUAL    OP    CHEMISTRY 

is  known  only  in  a  mercury  compound.  Although  the  radical,  vinyl, 
CH2:CH,  is  known  in  other  compounds  (see  Neurin,  p.  331),  there 
is  atomic  transposition,  with  formation  of  aldehyde,  CH2.CHO,  under 
conditions  in  which  vinyl  alcohol  might  be  formed. 

Allyl  Alcohol  — CH2:CH.CH2OH —  is  formed:  (1)  By  the  action 
of  sodium  upon  dichlorhydrin :  CH2C1.CHC1.CH2OH  +  Na2==CH2: 
CH.CH2OH  +  2NaCl;  (2)  by  heating  allyl  iodid  with  water:  CH2: 
CH.CH2I  +  H2O  =  CH2  :  CH.CH2OH  +  HI  ;  (3)  by  reduction  of 
acrolein  by  nascent  hydrogen:  CH2:CH.CHO+H2=CH2:CH.CH2OH. 

It  is  a  colorless,  mobile  liquid,  solidifies  at  — 50°  (  — 58°  F.), 
boils  at  97°  (206.6°  F.),  sp.  gr.  0.8507  at  25°  (77°  F.),  soluble  in 
water,  has  an  odor  resembling  the  combined  odors  of  alcohol  and 
essence  of  mustard,  burns  with  a  luminous  flame.  It  is  isomeric 
with  propylic  aldehyde  and  with  acetone.  Oxidizing  agents,  such  as 
silver  oxid,  convert  it  first  into  the  corresponding  aldehyde,  acrolein, 
then  into  the  acid,  acrylic  acid.  It  does  not  unite  readily  with 
hydrogen,  but,  in  presence  of  nascent  H,  union  takes  place  slowly, 
with  formation  of  normal  propyl  alcohol.  It  forms  products  of 
addition  with  chlorin,  bromin  and  iodin,  similar  to  those  derived 
from  glycerol.  Substitution  compounds  have  also  been  obtained, 
such  as  a  bromallyl  alcohol,  CH2 :  CBr.CH2OH,  derived  from  ft  di- 
bromo-propylene,  CH2:CBr.CH2Br. 

Propargyl  Alcohol  — CH?  C.CH2OH  —  first  of  the  acetylene 
alcohols,  is  formed  by  the  action  of  caustic  potash  upon  « bromallyl 
alcohol:  CH2:CBr.CH2OH  +  KHO  =  CH:  C.CH2OH  +  KBr+  H2O. 

Rhodinol  — Ci0H200  — b.  p.  114°;  geraniol,  CioHisO,  b.  p.  120°; 
and  linalool,  CioHigO,  b.  p.  198,  are  diolefin  alcohols,  which  are  the 
chief  constituents  of  the  essential  oils  of  rose,  geranium,  pelargonium, 
lavender,  bergamot,  etc. 

Acrylic  Aldehyde  — Acrolein  — CH2:CH.CHO  — the  first  of  the 
series  of  olefin  aldehydes,  is  the  substance  which  causes  the  disagree- 
able odor  developed  when  fats  or  oils  are  overheated.  It  is  formed  : 
(1)  By  oxidation  of  allylic  alcohol;  (2)  by  distilling  glycerol  with 
strong  H2S04  or  with  KHS04:  CH2OH.CHOH.CH2OH=CH2:CH.- 
CHO  +  2H2O. 

Acrolein  is  a  colorless  liquid,  having  a  pungent  odor,  and  giving 
off  a  vapor  which  is  intensely  irritating;  sp.  gr.  0.841  at  20° 
(68  °F.),  boils  at  52°  (125.6°  F.),  soluble  in  2-3  parts  of  water. 
Oxidizing  agents  convert  it  into  acrylic  acid.  Nascent  hydrogen 
reduces  it  to  allyl  alcohol.  It  does  not  combine  with  alkaline  bisul- 
fites.  It  reduces  ammoniacal  silver  nitrate  solution  as  does  acetic 
aldehyde.  It  suffers  change  even  when  kept  in  closed  vessels,  and 
deposits  a  white,  flocculent  material,  which  been  called  disacryl, 
while  formic,  acetic  and  acrylic  acids  are  also  produced. 


UNSATUEATED    ALIPHATIC    COMPOUNDS  373 

Croton  Aldehyde  —  CH3.CH:CH.CHO.—  By  the  action  of  diffuse 
daylight  upon  a  mixture  of  acetic  aldehyde,  H2O  and  HC1,  an  oily 
liquid  is  slowly  formed,  which  consists  chiefly  of  aldol,  or  fioxy- 
butyraldehyde,  CH3.CHOH.CH2.CHO.  This,  when  heated,  is  de- 
composed into  croton  aldehyde  and  water:  CH3.CHOH.CH2.CHO  = 
CH3.CH:CH.CHO  +  H2O. 

Croton  aldehyde  is  a  colorless  liquid;  boils  at  105°  (221°  F.), 
gives  off  highly  irritating  vapors;  sp.  gr.  1.033  at  0°  (32°  F.).  It 
is  reduced  by  nascent  H  to  crotonyl  alcohol,  CH3.CH:CH.CH2OH. 

Propargyl  Aldehyde  —  CH  •  C.CHO  —  is  an  acetylene  aldehyde, 
a  liquid,  which  boils  at  59°  (138.2°  F.). 

Citronellal,  CioHigO,  b.  p.  104°,  is  an  olefin  aldehyde,  existing  in 
citronella  and  other  essential  oils.  Geranial,  CioHieO,  b.  p.  226°,  is 
a  diolefin  aldehyde  existing  in  lemon  oil,  and  formed  from  geraniol. 

Mesityl  Oxid,  (CH3)2C:CH.CO.CH3,  and  Phorone,  (CH3)2C  : 
CH.CO.CH:C(CH3)2,  are  examples,  respectively,  of  olefin  and 
diolefin  ketones.  They  are  produced  together  by  the  action  of 
dehydrating  agents,  such  as  H2SO*  and  ZnCl2,  upon  acetone.  Mesityl 
oxid  is  a  liquid,  boiling  at  130°,  and  having  the  odor  of  peppermint. 
Phorone  is  a  solid,  fusing  at  28°,  and  boiling  at  196°.  Methyl- 
heptenone,  (CH3)2C:CH.CH2.CH2.CO.CH3,  another  olefin  ketoue,  is 
a  liquid  having  a  penetrating  odor,  boiling  at  173°,  which  exists  in, 
or  is  produced  from,  many  essential  oils. 

Oleic  Acids. — The  acids  of  this  series  are  monocarboxylic  acids 
derived  from  the  olefins,  and  contain  two  atoms  of  hydrogen  less 
than  the  corresponding  terms  of  the  acetic  series.  They  are  formed: 
(1)  By  oxidation  of  their  corresponding  alcohols  or  aldehydes.  Thus 
allylic  alcohol,  CH2:CH.CH2OH,  or  acrolein,  CH2:CH.CHO,  yield 
acrylic  acid,  CH2:CH.COOH;  (2)  by  the  action  of  alcoholic  KHO 
upon  the  monohalogen  fatty  acids.  Thus  ft  monobromo  propionic 
acid  yields  acrylic  acid  :  CH2Br.CH2.COOH  +  KHO  =  CH2  :  CH.- 
COOH  +  KBr  +  H2O;  (3)  by  dehydration  of  acids  of  the  oxyacetic 
series.  Thus  ethylene  lactic  acid  (ft  oxypropionic,  p.  293)  forms 
acrylic  acid  when  heated:  CH2OH.CH2.COOH  =  CH2:CH.COOH  + 
H2O;  (4)  from  the  allyl  haloids  (p.  371),  by  conversion  into  cyanids 
and  saponification.  Thus  cro tonic  acid  is  obtained  from  allyl  iodid: 
KCN==CH2:CH.CH2CN  +  KI,  and  CH2:CH.CH2- 
CH2:CH.CH2.COOH  +  NH4C1  (p.  278). 

The  oleic  acids  combine  with  the  hydracids  to  form  monohalogen 
fatty  acids,  the  halogen  assuming  the  position  furthest  removed  from 
the  carboxyl.  Thus  acrylic  acid  and  hydriodic  acid  form  ft  iodo 
propionic  acid:  CH2:CH.COOH  +  HI  =  CH2I.CH2.COOH.  Heated 
with  caustic  alkalies  to  100°,  they  form  oxyacids.  Thus  acrylic  acid 
forms  a  lactic  acid:  CH2:CH.COOH  +  KHO  =  CH3.CHOH. COOK. 


374  MANUAL    OF    CHEMISTRY 

But,  when  fused  with  caustic  alkalies,  they  are  decomposed  into 
fatty  acids,  with  loss  of  H.  Thus  acrylic  acid  yields  formic  and 
acetic  acids:  CH2:CH.COOH+2KHO  =  H.COOK+CH3.COOK+H2. 
The  Py  acids,  i.  e.,  those  in  which  the  double  bond  is  between  the 
ft  and  y  positions,  as  in  ethidene  propionic  acid,  CH3.CH:CH.CH2. 
COOH,  when  heated  with  H2SO4  form  lactones  (p.  320). 

Acrylic  Acid  —  CH2:CH.COOH  —  is  best  obtained  by  oxidizing 
acrolem  with  silver  oxid.  It  is  a  liquid  below  7°  (44.6°  F.),  boils 
at  140°  (284°  F.),  mixes  with  water,  and  has  an  odor  like  that  of 
acetic  acid. 

Crotonic  Acids.  —  Three  crotonic  acids  are  known,  two  of 
which  are  space  isomerids  (pp.  267,  375)  :  Ordinary  crotonic  acid, 
CH3\  /COOH 

/>C:C<(          ,    a   crystalline   solid,   fusible  at  72°    (161.6°  F.); 

Hv  /COOH 

isocrotonic  acid,        /C:C^          ,  a  liquid  boiling  at  75°  (167°  F.), 

CH3  H 

and  methacrylic  acid,  CH2:C<(cHOH»  a  crystalline  solid,  f.  p.  16°, 
b.  p.  160°. 

Angelic  Acid—  CH3/^:^\CH3H  —  *s  a  crystalline  solid,  f.  p.  45°, 
b.  p.  185°,  having  an  aromatic  odor,  soluble  in  water,  alcohol  and 
ether.  It  exists  free  in  angelica  root,  and,  in  its  esters,  in  oil  of 
cumin  and  in  oil  of  anthemis.  Tiglic  acid  —  Methyl-crotonic  acid  — 

—  isomeric  with  angelic  acid,  exists  as  a  glycerid  in 


croton  oil,  and,  as  its  amyl  ester,  in  oil  of  cumin.  It  is  a  crystalline 
solid,  f.  p.  65°,  b.p.  198°. 

Hypogaeic  Acid  —  Ci5H29.COOH  —  accompanies  arachic  acid 
(p.  284)  as  its  glycerid,  in  peanut  oil.  It  is  a  crystalline  solid, 
f.p.  33°,  b.p.  236°. 

Oleic  Acid  —  CH3.(CH2)7.CH:CH.(CH2)7.COOH  —  exists  as  its 
gly  eerie  ester  in  fats  and  fixed  oils,  and  is  obtained  in  an  impure 
form,  on  a  large  scale,  as  a  by-product  in  the  manufacture  of  stearin 
candles. 

Pure  oleic  acid  is  a  white,  pearly,  crystalline  solid,  fuses  at  14° 
(57.2°  F.),  odorless,  tasteless,  soluble  in  alcohol  and  in  ether,  insol- 
uble in  water,  sp.  gr.  0.808  at  19°  (66.2°  F.),  and  neutral  in  reaction. 
Exposed  to  air,  the  liquid  acid  absorbs  oxygen,  and  becomes  yellow, 
rancid  in  taste  and  odor,  acid  in  reaction,  and  incapable  of  solidifi- 
cation on  cooling.  Nitric  acid  oxidizes  it,  with  formation  of  the 
lower  fatty  acids  and  sebacic  acid,  CioHigtX  Heated  to  200° 
(392°  F.)  with  excess  of  caustic  potash,  it  is  split  into  palmitic  and 
acetic  acids  :  Ci8H34O2  +  2KHO  =  Ci6H3i02K  +  C2H3O2K  +  H2.  The 
oleates  of  the  alkaline  metals  are  soft,  soluble  soaps;  those  of  the 
earthy  metals  are  insoluble  in  water.  The  action  of  iodin  and  of 


UNSATURATED    ALIPHATIC    COMPOUNDS  375 

bromin  upon  oleic  acid  is  utilized  in  the  analysis  of  fats  and  oils. 
At  the  ordinary  temperature  the  fatty  acids,  including  palmitic  and 
stearic,  are  not  affected  by  iodin,  but  the  double  bond  in  oleic  acid 
is  broken,  and  one  molecule  of  oleic  acid  combines  with  two  atoms 
of  iodin.  Under  like  conditions  each  molecule  of  linoleic  acid  (see 
below)  takes  up  four  atoms  of  iodin.  The  amount  of  iodin  which  a 
given  weight  of  a  fat  or  oil  can  combine  with  will  increase  with  its 
tenure  of  oleic,  or,  particularly,  of  linoleic  acid.  "HubFs  iodin 
number "  of  a  fat  or  oil  is  the  quantity  of  iodin  which  100  grams 
of  the  substance  can  take  up  under  the  conditions  of  the  process, 
and  is  an  important  factor  for  its  identification. 

Elaidic  Acid — CuHss.OOOH  —  is  an  isomere  of  oleic  acid,  pro- 
duced from  it  by  the  action  of  nitrous  acid.  It  is  a  crystalline  solid, 
fusible  at  51°  (123.8°  F.).  Its  formation  is  utilized  to  distinguish 
non-drying  from  drying  oils  (p.  318).  The  former,  containing  oleic 
acid,  solidify  when  acted  on  by  nitrous  acid;  the  latter,  containing 
linoleic  acid,  do  not. 

Ricinoleic  Acid— CH3.(CH2)5.CHOH.CH2.CH:CH.(CH2)7.COOH 
-  is  an  un saturated  oxyacid,  which  exists  as  its  glyceric  ester  in 
castor  oil. 

Linoleic  Acid  —  CuHsi.COOH  —  is  an  unsaturated,  pure  acid, 
containing  two  atoms  of  hydrogen  less  than  oleic  acid.  It  exists 
as  its  glyceric  ester  in  the  drying  oils,  which  dry  and  solidify  on 
exposure  to  air. 

Propargylic  Acid — Propiolic  Acid  —  CH  =  C.COOH — correspond- 
ing to  propargylic  alcohol,  is  an  example  of  an  acetylene  monocar- 
boxylic  acid.  It  is  a  liquid,  having  the  odor  of  acetic  acid.  Sorbic 
acid,  CH3.CH:CH.CH:CH.COOH,  is  a  diolefin  monocarboxylic  acid, 
derived  from  parasorbic  acid,  which  is  an  unsaturated  oxyolefin  acid 
occurring  in  the  berries  of  the  mountain  ash. 

Olefin  dicarboxylic  Acids.  —  The  acids  of  this  series  contain  two 
atoms  of  hydrogen  less  than  the  corresponding  acids  of  the  oxalic 
series,  and  they  consequently  bear  the  same  relation  to  those  acids 
that  the  acids  of  the  oleic  series  bear  to  those  of  the  acetic  series. 

Esters  of  three  acids  having  the  composition  C2H2(COOH)2  are 
known.  The  free  acid  corresponding  to  one  of  these,  methylene 

/r^r\r\(c*  Tf    \ 

malonic  ester,  CH2:C<^COQ(C*H5)'  *s  no^   known.     The  other  two, 
fumaric    and    maleic    acids,    are    "space    isomerids  "    (p.     268). 
Fumaric  acid  is  considered  to  have  the  axial  symmetric  structure: 
H.C.COOH 

II  ,  because  it  does  not  yield  an  anhydrid,  and  because,  on 

HOOC.C.H 

oxidation,  it  yields  racemic  acid,  while  maleic  acid  has  the  plane  sym- 
metrical structure,  because,  owing  to  the  closer  proximity  of  the  car- 


376  MANUAL    OF    CHEMISTRY 

H.C.COOH  H.C.COv 

boxyls,      II  ,  it  readily  forms  an  anhydrid,      II       /O,  and  be- 

H.C.COOH  H.C.CO/ 

cause  on  oxidation  it  yields  inactive,  or  meso-tartaric  acid*  (see  p. 
267  and  Fig.  31,  ibid.). 

Fumaric  acid  exists  free  in  many  plants,  notably  in  Iceland  moss. 
Fumaric  and  maleic  acids  are  readily  converted  one  into  the  other  by 
simple  heating,  and  the  two  are  produced  together  by  the  action  of 
heat  upon  malic  acid  (p.  295),  or  by  boiling  solutions  of  monobromo- 
succinic  acid  (p.  288). 

Fumaric  acid  crystallizes  in  small  prisms,  almost  insoluble  in 
cold  water,  which  sublime  at  200°  (392°  F.).  Maleic  acid  fuses  at 
130°  (266°  F.),  and  boils  at  160°  (320°  F.).  Both  fumaric  and 
maleic  acids  are  converted  into  succinic  acid  by  nascent  hydrogen. 

Five  unsatu  rated,  open  chain  acids  are  known  having  the  formula 
CslMCOOHh,  the  next  superior  homologues  of  fumaric  and  maleic 
acids.  One  of  these,  ethidene  malonic  acid,  is  only  known  in  its  es- 

ters CH3.CH:C<^oo(C2H5J-  Tne  structural  formulae  of  the  others  are: 

H.C.COOH  H.C.COOH          CH2:C.COOH  CH2.COOH 

II  H  I  I 

COOH.C(CH3)  (CH3)C.COOH  CH2.COOH  CH 

II 
CH.COOH 

Mesaconic  acid  Citraconic  acid  Itaconic  acid  Glutaconic  acid. 

(Methyl-fumaric).  (Methyl-maleiic).  (Methylene  succinic). 

Mesaconic  acid  is  formed  by  heating  citraconic  or  itaconic  acid 
with  water  at  200°  (392°  F.).  It  is  difficultly  soluble  in  water,  and 
fuses  at  202°  (395.6°  F.).  Citraconic  acid  is  obtained  from  its 

H.C.CO, 
anhydrid,         II          O,  formed  in  the  distillation  of  citric  acid,  by 


heating  with  water.  Easily  soluble  in  water,  f  .  p.  80°  (176°  F.). 
Itaconic  acid  is  similarly  obtained  from  its  anhydrid,  a  product  of 
distillation  of  aconitic  acid,  f.  p.  161°  (320.2°  F.)  .  Glutaconic  acid  is 
formed  by  the  action  of  barium  hydroxid  upon  coumalic  acid,  an  oxy- 

CH  -  C.COOH 
diolefin  monocarboxylic  acid,  having  the  composition  I 

O.CO.CH:CH. 

It  fuses  at  132°  (269.6°  F.). 

Aconitic  Acid—  COOH.CH2.C(COOH)  :  CH.COOH—  is  an  olefin 
tricarboxylic  acid.  It  exists  as  its  Ca  salt  in  a  number  of  plants, 
including  aconitum,  equisetum,  sugar-cane  and  beet-root.  It  is 
formed  by  heating  citric  acid  (p.  297),  either  alone  or  with  HC1  or 
H2SO4.  It  is  also  obtained  synthetically  from  a  mixture  of  acetic 
and  oxalic  esters.  It  forms  crystalline  plates  or  prisms,  soluble  in 
water,  alcohol,  and  ether,  fuses  at  191°  (375.8°  F.).  Heat  decom- 


UNSATURATED    SULFUR    AND  NITROGEN  COMPOUNDS          377 

poses  it  into  itaconic  acid  and  CO2.     Nascent  hydrogen  reduces  it  to 
tricarballylic  acid  (p.  289). 

Allyl  Oxid— Allylic  ether—  (CH2:CH.CH2)2O— is  an  example  of 
the  unsaturated  ethers.  It  exists  in  small  quantity  in  crude  essence 
of  garlic,  and  is  formed  by  the  action  of  allyl  iodid  upon  sodium- 
allyl  oxid.  It  is  a  colorless  liquid,  having  the  odor  of  garlic,  insol- 
uble in  water,  boiling  at  82°  (179.6°  F.).  Mixed  ethers  are  also 
known,  such  as  propargyl  ethyl  ether,  CH :  C.CH2.O.CH2.CH3. 


UNSATURATED    SULFUR   AND   NITROGEN    COMPOUNDS. 

Allyl  Sulfid — (CH2:CH.CH2) 28— corresponding  to  the  oxid,  is  the 
principal  constituent  of  volatile  oil  of  garlic,  obtained  by  distilling 
garlic  with  water.  It  is  formed  by  the  action  of  alcoholic  solution  of 
potassium  sulfid  upon  allyl  iodid.  It  is  a  colorless  oil,  lighter  than 
water,  soluble  in  alcohol  and  in  ether,  boils  at  140°  (280°  F.). 

Allyl  Isothiocyanate— Mustard  oil— S:C:N.CH2.CH:CH2— is  the 
chief  constituent  of  volatile  oil  of  mustard,  and  of  radish  oil.  It  is 
prepared  artificially  by  distilling  allyl  bromid  or  iodid  with  potassium 
or  silver  thiocyanate:  S:C:N.Ag+CH2I.CH:CH2=S:C:N.CH2.CH:- 
CH2+AgI.  It  does  not  exist  preformed  in  the  mustard  seeds,  but  is 
produced  by  the  decomposition  of  a  glucosid,  potassium  myronate 
(p.  413),  in  the  presence  of  water  under  the  influence  of  an  enzym, 
also  contained  in  the  seeds,  called  myrosin.  The  action  takes  place 
at  0°  (32°  F.),  but  not  at  temperatures  above  40°  (104°  F.).  The 
activity  of  myrosin  is  also  impaired  by  the  presence  of  acetic  acid 
(vinegar).  The  pungent,  rubefacient  and  vesicant  actions  of  mus- 
tard are  due  to  mustard  oil. 

Pure  allyl  isothiocyanate  is  a  colorless  oil,  sp.  gr.,  1.015  at  20° 
(68°  F.),  boils  at  150°  (302°  F.),  has  a  penetrating,  pungent  odor, 
sparingly  soluble  in  water,  very  soluble  in  alcohol  and  in  ether.  Ex- 
posed to  air  it  gradually  turns  brownish -yellow,  and  deposits  a  resi- 
noid  material.  Heated  with  HC1  or  with  H2O,  it  is  decomposed  into 
carbon  dioxid,  hydrogen  sulfid  and  allyl-amin :  S :  C :  N.CH2.CH :  CH2-+- 
2H20=CO2-f  SH2+NH2.CH2.CH :  CH2. 

Allyl-amin  is  the  superior  homologue  of  vinyl-amin,  which  is 
capable  of  uniting  with  sulfur  dioxid  and  water  to  produce  taurin  or 
amido-isethionic  acid  (p.  366)  :  NH2.CH:CH2-hSO2+H20=NH2.- 
CH2 .  CH2 .  SOsH . 


378  MANUAL    OP    CHEMISTRY 


CLOSED  CHAIN  COMPOUNDS  —  CYCLIC  COMPOUNDS. 

These  compounds,  which  include  many  important  natural  products, 
and  a  practically  unlimited  number  of  synthetic  compounds,  differ 
from  the  members  of  the  open  chain  series  in  that  they  contain  a 
group  of  more  than  two  atoms  united  together  by  exchange  of  va- 
lences in  such  a  manner  as  to  form  a  closed  chain,  or  ring,  or 
nucleus.  If  all  the  atoms  so  united  are  carbon  atoms  the  substance 
belongs  to  the  carbocyclic  class;  if  an  element  other  than  carbon 
enters  into  the  formation  of  the  ring  the  substance  is  heterocyclic. 

Some  closed  chain  compounds  are  produced  by  the  interaction 
of  two  open  chain  compounds,  as  in  the  formation  of  certain  diamins 
(p.  330)  and  compound  ureas  (p.  351).  Others,  such  as  the  lactids 
(p.  320),  lactones  (pp.  320,  362),  and  lactams  (p.  362),  are  produced 
by  internal  reaction  in  an  open  chain  molecule.  But  the  principal 
method  of  formation  of  closed  chain  compounds  is  by  polymerization. 
In  some  cases  this  takes  place  at  comparatively  low  temperatures,  as 
in  the  formation  of  trioxymethylene  from  formaldehyde  (p.  257),  and 
of  the  polymeric  thioaldehydes  and  their  sulfones  (p.  322). 

Among  the  instances  of  formation  of  cyclic  from  acyclic  com- 
pounds there  is  one  of  polymerization  at  a  high  temperature  which  is 
of  special  interest  as  bearing  upon  the  constitution  of  the  cyclic 
compounds.  The  central  figure  of  the  carbocyclic  compounds  is 
benzene,  CeHe,  which  is  obtained  principally  from  gas -tar.  Coal  gas 
contains  acetylene,  C2H2,  and  it  is  easy  to  conceive  that  one  or  two 
of  the  bonds  uniting  the  two  carbon  atoms  in  acetylene  may  be 
loosened  under  the  influence  of  heat,  and  that  a  molecule  of  benzene 
may  be  produced  by  fusion  of  three  molecules  of  acetylene  :  3C2H2= 
CeHe.  The  product  so  obtained  is  neither  dipropargyl,  HCiC.CEb.- 
CH2.C:CH,  nor  dimethyl  diacetylene,  H3C.C  i  C.C  I  C.CH3  (p.  229), 
but  another  substance,  the  nature  of  whose  substituted  derivatives 
indicates  that  the  six  hydrogen  atoms  are  of  equal  value,  and  there- 
fore similarly  attached  to  carbon  atoms;  and,  there  being  three  bisub- 
stituted  derivatives  (p.  381),  to  at  least  three  different  carbon  atoms. 
These  conditions  can  only  be  fulfilled  by  a  cyclic  structure  of  the 
molecule  of  benzene  and  its  derivatives  (p.  380).  Pyridin  also,  which 
has  a  prominence  among  the  heterocyclic  compounds  corresponding 
to  that  of  benzene  among  the  carbocyclic,  has  been  obtained  from 
acetylene  and  hydrocyanic  acid  by  a  fusion  very  similar  to  that  by 
which  acetylene  alone  forms  benzene  :  2C2H2+HCN=C5H5N.  It  is 
also  formed  by  the  action  of  heat  upon  substances  containing  nitro- 
gen as  well  as  carbon  (p.  459) 


CAEBOCYCLIC    COMPOUNDS  379 


CARBOCYCLIC    COMPOUNDS. 

Carbocyclic  compounds  are  known  containing  from  three  to  seven 
carbon  atoms  in  a  ring.  Compounds  are  also  known  containing  a 
much  larger  number  of  carbon  atoms,  but  these  are  formed  by  fusion 
or  union  of  two  or  more  rings  of  six  carbon  atoms  or  less,  or  by  the 
attachment  of  an  open  chain  grouping  upon  a  closed  chain  one 
(p.  438).  The  hexacarbocyclic  compounds  are  far  more  numerous 
and  important  than  the  others. 

The  mononuclear  carbocyclic  hydrocarbons  have  algebraic  for- 
mula varying  from  C«H2»  to  C«H2«-e,  and  are  isomeric  with  the  un- 
saturated  open  chain  hydrocarbons  (p.  229).  Those  of  the  series 
C»H2»  are  known  as  polymethylenes,  being  considered  as  formed  by 
the  union  of  a  number  of  methylene  groups,  CH2.  Thus  hexahydro- 


benzene  is  hexamethylene,  C^Hc*     CH2.     But  the  chemical 


/ 

relations  of  the  polymethylenes  to  the  saturated  hydrocarbons  is 
closer  than  that  to  their  isomeres,  the  olefins,  because,  containing  no 
double  linkages,  they  cannot  be  modified  by  addition  without  disrup- 
tion of  the  ring.  So  long  as  the  cyclic  formation  is  maintained,  the 
polymethylenes  are  saturated  compounds,  as  are  the  paraffins.  For 
this  reason  their  "  Geneva  "  names  are  the  same  as  those  of  the  paraf- 
fins of  like  carbon  content,  to  which  is  prefixed  the  syllable  "cyclo," 
and  they  are  known  generically  as  cycloparaffins  ;  or  the  symbol  R 
is  used  in  place  of  the  syllable  "cyclo."  The  hydrocarbons  of  the 
series  C*H2«-2,  isomeric  with  the  acetylenes  and  diolefins,  are  referable 
to  the  latter,  not  to  the  former,  as  they  cannot  contain  a  triple  link- 
age in  the  ring.  But,  containing  only  one  double  linkage,  they  are 
more  closely  related  to  the  olefins.  Therefore  tetrahydrobenzene, 
CH\CH2j(mOCH2'  isomeric  with  hexadiene,  CH2:CH.CH2.CH2.CH:- 
CH2,  containing  but  one  double  linkage,  is  cyclo-hexene,  or  R- 
hexene.  Similarly  dihydrobenzene,  CH^H^CH^CH,  is  a  cyclo- 
diolef  in  :  R-hexadiene  ;  and  benzene  a  cyclotriolefin  :  R-hexatriene. 
The  cycloparaffins  are  formed  by  the  action  of  sodium  upon  the 

dibromoparaffins.     Thus  trimethylene  is  obtained  from  trimethylene 

/CH2 
bromid:  CH2Br.CH2.CH2Br+Na2==CH2     I     +2NaBr. 

\CH2 

Tri-,  tetra-.penta-,  and  hepta-carbocyclic  hydrocarbons,  and  their 
numerous  derivatives,  notably  acids  and  ke  tones,  are  known.  They 
are  not  as  yet,  however,  of  medical  interest,  except  that  certain 
tetra-,  and  penta-  compounds  are  among  the  decomposition  products 
of  certain  alkaloids. 


380  MANUAL    OF    CHEMISTRY 


HEXACARBOCYCLIC    COMPOUNDS  —  AROMATIC 
SUBSTANCES. 

These  compounds,  which  are  very  numerous  and  important,  all 
contain  a  group  of  six  carbon  atoms,  to  which  are  attached  six,  eight, 
ten  or  twelve  univalents,  or  their  equivalent.  As  the  simplest  repre- 
sentative of  the  class  is  benzene,  CeHe,  and  as  all  of  these  bodies  may 
be  derived  from  benzene,  directly  or  indirectly,  and  yield  that  hydro- 
carbon on  decomposition,  the  aromatic  substances  may  be  considered 
as  derivatives  of  benzene.  This  being  the  case,  the  constitution  of 
benzene  itself  is  of  great  importance,  and  has  been  the  subject  of 
much  study.  Several  schematic  representations  of  the  structure 
of  the  benzene  molecule  have  been  suggested,  the  most  demonstrative 
of  which  are  the  hexagonal  form  of  Kekule,  the  prismatic  form  of 
Ladenburg,  and  the  diagonal  form  of  Claus: 

H  H 

H  |  H 


0 C 

C  \   H    /  4 


H 

\l, 
C 

c I c 


H— C 


#  \ 

H-C         C— H 

I      I 

I\l/l 


\ 


C— H 


C— H 


Hexagonal.  Prismatic.  Diagonal. 

In  the  hexagonal  formula  the  carbon  atoms  exchange  one  and  two 
valences  alternately,  each  being  attached  to  two  others;  in  the  pris- 
matic form  each  carbon  atom  is  attached  to  three  others  by  single 
valences;  and  in  the  diagonal  form  the  hexagon  is  retained,  but,  in 
place  of  double  linkages,  a  central  linkage  between  all  the  carbon 
atoms  is  substituted.  All  of  these  formulae  represent  the  equivalence 
of  the  carbon  atoms,  and  the  constitution  of  isomeres  equally  well 
(see  below).  The  prismatic  formula  cannot  be  modified  to  represent 
a  constitution  of  the  additive  derivatives  of  benzene,  such  as  dihydro- 

benzene,  CH^H^Clf^H,  and  tetrahydrobenzene,CH^cH!cH^2/CH2- 
Neither  the  prismatic  nor  the  diagonal  formula  admits  double  linkages 
between  carbon  atoms  in  the  ring.  That  these  exist  is  shown,  how- 
ever, by  the  formation  of  the  additive  products  mentioned,  by  the 
formation  of  anhydrids  from  or tho- derivatives  only  (see  below),  and 
by  certain  physical  properties.  Moreover,  the  hexagonal  formula  ac- 


HEXACARBOCYCLIC  COMPOUNDS  381 

cords  well  with  the  tetrahedral  representation  of  the  valences  of  the 
carbon  atom  (p.  267),  the  six  tetrahedra  being  alternately  united  by 
edges  and  apexes  in  benzene,  and  by  apexes  in  hexahydrobenzene. 
For  these  (and  other)  reasons,  chemists  have  very  generally  adopted 
the  hexagonal  expression,  although  it  still  leaves  something  to  be 
desired.  The  figure  of  a  hexagon  is  used  in  chemical  writings  to  rep- 
resent the  benzene  ring.  If  used  alone  it  represents  a  molecule  of 
benzene,  CeHe;  and  to  represent  the  products  of  substitution  the  sym- 
bols of  the  substituted  group  are  written  in  the  proper  position, 
thus  : 

COOH 


H2 

Benzene.  Benzole  acid.  Dihydrobanzene.  Phthalie  anhydrid. 

Isomery  of  Benzene  Substitution  Products. — (1)  The  six  atoms 
of  hydrogen  in  benzene  are  of  equal  value.  There  exists  but  one 
mono -substituted  derivative  of  benzene  containing  any  given  univa- 
lent:  one  chlorobenzene,  CeHsCl,  one  nitro- benzene,  CeHsCNC^),  one 
amido -benzene,  CeH^NH^),  one  benzoic  acid,  CeHs.COOH,  etc. 
Therefore,  benzene  is  symmetrical  in  structure,  and  its  hydrogen 
atoms  equal  each  other  in  value,  as  do  those  of  methane,  while  those 
of  pyridin  (p.  454)  are  not  all  of  like  value. 

2.  Any  hydrogen  atom  selected  in  the  benzene  ring  is  symmetrically 
placed  in  reference  to  two  pairs  of  hydrogen  atoms,  and  to  the  sixth 
hydrogen  atom  individually.  With  all  di-,  tri-,  and  tetra-substituted 
derivatives  oi  benzene,  containing  like  substituted  univalents,  there 
are  three  isomeres.  Three  dichloro-,  three  trichloro-,  and  three 
tetrachloro- benzenes,  etc.,  and  in  no  instance  are  more  than  three 
known.  There  is  but  one  explanation  of  the  facts  mentioned  above, 
namely,  that  the  different  bi-,  tri-,  and  tetra- derivatives  are  pro- 
duced by  differences  in  the  relative  positions  of  the  substituted 
groups,  by  differences  in  "  orientation,"  as  among  the  aliphatic  com- 
pounds, the  several  oxyacids  are  "place  isomeres"  of  each  other 
(p.  290). 

The  hexagonal  formula  of  benzene  is  very  convenient  for 
showing  the  structure  of  the  several  isomeres.  For  this 
ourpose  the  carbon  atoms  are  numbered,  beginning,  for 
gonvenience,  at  the  top  and  proceeding  clockwise. 

It  has  been  demonstrated  that  in  some  of  the  bisubsti- 
tuted  derivatives  the  two  substituted  groups  are  attached 
to  adjacent  carbon  atoms,  i.  e.,  to  1-2,  2-3,  3-4,  4-5,  5-6,  or  6-1. 


382 


MANUAL    OF    CHEMISTRY 


Clearly  for  each  carbon  atom  there  is  a  pair  of  adjacent  positions,  as 
1-2  and  1-6,  2-1  and  2-3,  etc.,  which  are  equivalent  to  each  other.* 
In  other  bisubstituted  derivatives  it  may  be  shown  that  the  two 
substituted  groups  are  attached  to  carbon  atoms,  separated  from  each 
other  by  one  carbon  atom  on  one  side  and  by  three  on  the  other,  an 
arrangement  which  renders  the  hexagon  unsymmetrical.  Such  posi- 
tions are  1-3,  2-4,  3-5,  4-6,  5-1,  and  6-2.  Or,  for  each  carbon  atom 
there  is  a  pair  of  equivalent  uu symmetrical  positions,  as  1-3  and  1-5, 
etc.  There  remains  but  one  other  arrangement  possible,  the  sym- 
metrical, or  diagonal,  1-4,  2-5,  3-6.  With  the  tri-  and  tetra-substi- 
tuted  derivatives  there  al-e  also  three  possible  arrangements:  the  adja- 
cent, vicinal,  or  consecutive,  as  1-2-3,  2-3-4;  1-2-3-4,  or  2-3-4-5; 
the  unsymmetrical,  as  1-2-4,  3-4-6;  1-2-3-5,  or  3-4-5-1;  and  the 
symmetrical,  as  1-3-5,  2-4-6;  1-2-4-5,  or  3-4-6-1.  Compounds  in 
which  the  substitution  is  adjacent  are  designated  as  ortho-com- 
pounds ( 'op0°'s=straight) ,  or,  in  writing,  by  the  abbreviation  o-,  or 
by  the  figures  1-2,  etc.  Thus  CeEUfOH^d-a),  o-diphenol.  Unsym- 
metrical compounds  are  designated  as  meta-compounds  (/xera- after), 
or,  abbreviated,  m-,  or  by  the  figures,  1-3,  etc.:  e.  g.,  CeHs- 
(Br)  3(1-2-4),  m-tribromobenzene.  Symmetrical  compounds  are  desig- 
nated as  para-compounds  (rapa- beside),  abbreviated  p-,  or  1-4,  etc.: 
e.  g.,  C6H2(NH2) 4(1-2-4-5),  p-tetraamido- benzene.  Or,  to  illustrate  by 
the  formulae  of  the  di-  and  tetra-chlorobenzenes  : 


Cl 


Cl 


Cl 


Cl 


1-2-3-4  1-2-3-5 

Adjacent.  Unsymmetrical. 

Ortho.  Meta. 

*NOTE.— The  principal  objection  to  the  hexagonal  formula  of  benzene  (and  stated  by  Kekule 
himself)  is  that  these  two  positions  are  not  entirely  equivalent,  as  in  the  position  1-2  the  grouping 
ls=C— C=,  while  in  1-6  it  is— C=C— ,  and  that  consequently  there  should  be  two  ortho  derivatives, 
while  but  one  is  known.  The  student  is  referred  to  more  extended  works  for  a  discussion  of  this 
subject. 


HEXACAEBOCYCLIC    COMPOUNDS 


383 


In  the  bisubstituted  derivatives  it  is  immaterial  whether  the  two 
substituted  groups  are  of  the  same  kind  or  different.  But  when,  in 
a  trisubstituted  derivative,  the  substituted  groups  are  not  the  same 
in  kind,  the  number  of  possible  isomeres  is  increased.  Thus  there 
are  six  possible  chloro-dibromobenzenes  (formulae  1  to  6  below),  of 
which  two  (1  and  2)  are  derived  from  orthodibromobenzene,C6H4:Br2(i,2) 
three  (3,  4,  and  5)  from  metadibromobenzene,  CeHsrB^d.a),  and  one 
(6)  from  paradibromobenzene,  C6H4:Br2d,4).  The  number  of  possible 
trisubstituted  derivatives  is  increased  to  ten  when  all  three  substituted 
groups  are  of  different  kind. 

Br  OH 


Cl 


Orthodibromo- 
metachloro. 


Cl 

2 

Orthodibromo- 
parachloro. 

Br 


Metadibromo- 
orthochloro. 


Br         Cl 


OH 


(N02) 


Metadibromo- 
allometachloro. 

In  naming  these  derivatives,  the  characterizing  group  of  the 
parent  substance  is  given  the  position  1  in  the  hexagon,  the  prefix 
"ortho"  is  applied  to  the  name  of  the  group  occupying  one  of  the 
ortho  positions  2  and  6,  "meta"  to  that  occupying  one  of  the  meta 
positions  3  and  5,  and  "para"  to  that  occupying  the  para  position  4. 
Thus  the  substance  having  the  formula  7  above  is  orthonitro-para- 
bromo-phenol.  But  another  substance  is  known,  not  identical  with 
this,  having  the  formula  8  above,  in  which  the  nitro  group  occupies 
the  second  ortho  position,  6.  To  distinguish  substances  such  as 
these,  the  designation  "allortho"  is  given  to  the  position  6,  and  the 
designation  "allometa"  to  the  position  5.  Thus  the  substance  having 
the  formula  8  is  metabromo-allorthonitro-phenol.  When  formulae 
are  used  the  numerals  corresponding  to  the  position  of  substitution, 
enclosed  in  brackets,  are  placed  after  the  symbols.  Thus  7  is  writ- 
ten: C6H3(OH)(NO2)[2]  Br[3],  and  8:  C6H3(OH)Br[3]  (NO2)r6j. 


384  MANUAL    OF    CHEMISTRY 

Classification  of   Aromatic    Substances. — The  benzene  deriva- 
tives may  be  classified  into  five  classes  : 

A.  Compounds  containing  a  single  benzene  nucleus,  unmodified 
except  by  substitution  for  hydrogen.    Monobenzenic  compounds.    In- 
cludes benzene  and  its  homologues,  and  the  phenols,  alcohols,  acids, 
etc.,  derived  from  them. 

B.  Compounds  containing  a  single  benzene  nucleus  in  which  one 
(or  more)  of  the  double  bonds  has  been  converted  into  a  single  one, 
thus  adding  two,  four,  or  six  valences  to  the  carbon  ring.     Monohy- 
drobenzenic  compounds.     Includes  the  cyclohexadienes,  cyclohexenes, 
and  cyclohexanes  (p.  379),  and  their  derivatives,  among  which  are 
the  terpenes  and  camphors. 

C.  Compounds  containing  two  (or  more)  benzene  nuclei,  or  ben- 
zene and  pentacarbocyclic  rings,  fused  together,  and  having  two  car- 
bon atoms  in  common.     Includes  indene,  fluorene,  naphthalene,  an- 
thracene, and  phenanthrene  and  their  derivatives.     Compounds  with 
condensed  nuclei. 

D.  Compounds  containing  two  (or  more)  benzene  rings,  directly 
united  by  loss  of  two  H  atoms.     Diphenyl  and  its  derivatives. 

E.  Compounds  containing  two  (or  more)  benzene  nuclei,  united 
by  aliphatic  groups.     Includes  di-  and   polyphenyl  paraffins,  olefins 
and  acetylenes  and  their  derivatives. 

The  following  formulae  will  serve  to  indicate  the  differences  in 
constitution  of  the  several  classes  : 

CH3  H2  H        H 

I  II  II 

C  C  CO 

-/  \  /  \  </  \  /  \ 

H— C          C— H  H2C          CH2  H— C          C         C— OH 

I  II  II  I  II  I 

H— C          C— H  H,C          CH2  H— C          C          C-H 

v        v          v  y 

H  H2  H         H 

(A)  (B)  (C) 

Methyl-benzene.  Hexahydrobenzene.  /3  Naphthol. 


HHHH  HH         HH 

II      II  .11          || 

c=c    c=c  c=c      c=c 

(NH2).C       C.C       C.(NH2)   H— C  C— C— C       C— H 

\   /  \  '  /  \-  S  *•  \   ? 

c— c    c— c  c— c      c— c 

I  I    I  I  II       II 

HHHH  HH         HH 

(D)  (E) 

pa— Diamido-diphenyl.  Diphenyl-methane. 


MONOBENZENIC   HYDROCARBONS  385 

A.    MONOBENZENIC   COMPOUNDS. 

HYDROCARBONS. 

Benzene  —  Benzol  — CoH.G—( not  to  be  confounded  with  benzine, 
a  mixture  of  hydrocarbons  of  the  series  C«H2«+2,  obtained  from 
petroleum  —  p.  232)  does  not  exist  in  nature.  It  is  obtained,  pure, 
by  decomposing  benzoic  acid  by  heating  with  slaked  lime:  CeHs.- 
COOH-fCaH2O2  =  CaC03+C6H6  +  H2O.  It  is  produced  in  the 
distillation  of  coal,  and  exists  in  coal  tar,  from  which  it  is  obtained 
for  use  in  the  arts. 

Coal  tar,  or  gas  tar,  is  a  very  complex  mixture,  containing  forty 
or  fifty  substances  —  hydrocarbons,  phenols  and  bases  —  and  is  the 
crude  material  from  which  many  important  substances  are  obtained. 
In  working  it,  it  is  first  distilled,  four  fractions  being  collected: 
(1)  UgU  oil,  distilling  below  150°  (302°  F.);  (2)  carbolic  oil,  or 
middle  oil,  distilling  below  230°  (446°  F.).  Contains  phenols  and 
naphthalene.  (3)  Heavy  oil,  or  creasote  oil,  distilling  below  270° 
(518°  F.).  Furnishes  naphthalene.  (4)  Green  oil,  or  anthracene  oil, 
distilling  above  270°.  Contains  anthracene  and  other  solid  hydro- 
carbons. The  residue  in  the  still  is  pitch.  The  light  oil  contains 
benzene,  toluene  and  xylene,  with  some  thiophene,  phenols,  pyridin, 
and  heavy  oils.  It  is  further  purified  to  yield  various  grades  of 
commercial  "benzol,"  the  best  of  which  contains  about  70  per  cent, 
of  benzene,  and  24  per  cent,  of  toluene,  with  some  xylene,  cumene 
and  thiophene. 

Pure  benzene  is  a  colorless  liquid,  having  an  ethereal  odor,  crys- 
tallizing at  5.4°  (41.7°  F.),  boiling  at  80.5°  (176.9°  F.),  sp.  gr.  0.86 
at  15°  (59°  F.),  immiscible  with  water,  mixing  with  alcohol  and 
ether.  It  dissolves  I,  S,  P,  resins,  caoutchouc,  guttapercha,  fats  and 
many  alkaloids.  It  is  inflammable,  and  burns  with  a  smoky  flame. 

Benzene  unites  directly  with  Cl  or  Br  to  form  products  of  addition 
or  of  substitution.  Free  Cl  acts  only  slowly  upon  benzene  alone,  but 
the  action  is  much  accelerated  by  the  presence  of  certain  chlorids, 
particularly  Fe2Cle.  The  corresponding  I  derivatives  can  only  be 
obtained  indirectly.  Sulfuric  acid  combines  with  it  to  form  benzene 
sulfonic  acid,  CeHs.SOsH.  Nitric  acid  converts  it  into  nitro-benzene, 
Cells. NO2,  or,  if  fuming  HNOa  is  used  and  the  mixture  boiled,  into 
a  mixture  of  the  three  dinitro-benzenes,  C6H4(NO2)2.  It  is  reduced 
to  hexahydrobenzene  by  hydriodic  acid. 

Homologues  of  Benzene. —  These  may  be  considered  as  alkyl- 
benzenes,  formed  by  the  substitution  of  alkyl  groups  for  an  equivalent 
number  of  hydrogen  atoms  in  benzene.  The  usual  general  method 

25 


386  MANUAL    OF    CHEMISTRY 

of  their  formation  indicates  the  constitution:  they  are  obtained  by 
treating  a  mixture  of  bromobenzene,  ether,  and  the  bromid  or  iodid 
of  the  corresponding  alcoholic  radical  with  sodium.  Thus  mono- 
bromo- benzene  and  methyl  bromid  yield  methyl -benzene,  or  toluene: 
C6H5Br  +  CH3Br  +  Na2  =  2NaBr  +  C6H5.CH3.  They  are  also  formed 
by  the  action  of  the  alkyl  chlorids  upon  the  inferior  homologues  in 
presence  of  A^Cle,  or  of  ZnCl2,  or  Fe2Cl6.  Thus  benzene  and  methyl 
chlorid  form  toluene:  C6H6  +  CH3C1  =  C6H5.CH3  +  HC1.  This  is  a 
general  method  frequently  used  for  the  introduction  of  alkyls  into 
aromatic  compounds,  and  probably  depends  upon  the  formation  of 
intermediate  organo- metallic  compounds  (p.  325).  There  are  numer- 
ous other  methods  for  their  production.  The  superior  homologues 
of  benzene  include  many  isomeres.  Thus  there  are: 

1-C7H8,  i.e.,  C6H5(CH3)-Methyl-benzene, 

4-C8Hio,  i.  e.,  three  C6H4(CH3)2-o-,  m-,  and  p-Dimethyl-benzenes, 

C6H5  ( C2H5  )-Ethyl  -benzene, 
8-C9Hi2,  i.  e.,  three  C6H3(CH3)3-o-,  m-,  and  p-Trimethyl- benzenes, 

three  C6H4(CH3)(C2H5)-o-,  m-,  and  p-M ethyl -ethyl  benzenes, 
C6H5(C3H7)-Propyl-benzene, 
C6H5  ( C3H7  )-Isopropyl-benzene, 

19-CioHi4,  i.e.,  three  C<jH2(CH3)4-o-,  m-,  and  p-Tetramethyl  benzenes, 
three  C6H4(C2H5)2-o-,  m-,  and  p-Diethyl -benzenes, 
three  CeH3(CH3)2  (C2H5)-o-,  m-,  and  p-Dimethylethyl-benzenes, 
three  C6H4(CH3)(C3H7)-o-,  m-,  and  p-Methylpropyl -benzenes, 
three  C6H4(CH3)(C3H7)-o-,  m-,  and  p-Methylisopropyl-benzenes, 
four   C6H5(C4H9)-Butyl-benzenes. 

The  homologues  of  benzene  are  acted  upon  by  reagents  in  the 
same  manner  as  benzene  itself.  In  addition,  the  lateral  chain  may  be 
acted  upon.  Benzene  is  not  acted  upon  notably  by  oxidizing  agents 
unless  they  be  sufficiently  powerful  to  disrupt  the  molecule.  But 
oxidants  such  as  dilute  nitric  acid,  or  the  chromic  mixture,  oxidize 
the  lateral  chain  in  the  homologues  of  benzene,  with  formation  of 
carboxylic  acids.  Thus  methyl -benzene,  CeHs.CHs,  yields  benzoic 
acid,  C6H5.COOH. 

Toluene — Toluol — Methyl-benzene  —  CeHs.CHa  —  exists  in  the 
products  of  distillation  of  coal,  wood,  etc.,  and  is  a  constituent  of 
commercial  benzene.  It  is  formed  synthetically  by  the  general  meth- 
ods given  above ;  or  may  be  obtained  pure  by  decomposition  of  one  of 
the  toluic  acids  by  lime. 

It  is  a  colorless  liquid,  boils  at  110.3°  (230. 5°  F.),  does  not  so- 
lidify at  —20°  (—4°  F.),  sp.  gr.  0.872  at  15°  (59°  F.),  does  not  mix 
with  water,  but  mixes  with  alcohol,  ether  and  carbon  disulfid. 

Xylenes — Xylols — CsHio. — Four  isomeres  are  possible  and  are 
known:  ethyl-benzene,  CeHs.CgHs — and  ortho-  (1 — 2),meta-(l — 3), 


HALOID    DERIVATIVES    OF    BENZENE,    ETC.  387 

and  para-  (1 — 4),  dimethyl-benzenes,  C6H4(CH3)2.  Ethylbenzene  is 
a  colorless  oil,  boiling  at  134°  (273.2°  F.),  obtained  by  fractional 
distillation  of  animal  oil.  The  three  dimethyl  benzenes  exist  in  coal 
tar  and  in  the  commercial  xylene,  which  boils  at  139°  (282. 2°  F.), 
70%  consisting  of  metaxylene,  and  paraxylene  being  present  in  very 
small  amount.  Mesitylene,  formed  by  distilling  acetone  or  allylene 
with  H2S04  is  p-trimethylbenzene.  Cymene,  a  liquid  having  a 
pleasant  odor,  present  in  several  ethereal  oils,  is  p-methylisopropyl- 
benzene.  It  is  formed  by  the  action  of  methyl  iodid  upon  p-bromo 
isopropyl  benzene  in  presence  of  sodium. 

MONOBENZENIC  HYDROCARBONS  WITH  UNSATURATED  LATERAL 

CHAINS. 

These  are  similar  in  constitution  to  the  homologues  of  benzene, 
except  that  the  lateral  chains  are  olefins  or  acetylenes,  in  place  of 
paraffins. 

Styrolene —  Cinnamene  —  Ethylenebenzene  —  Phenylethene  — 
CeHs.CHrCEb — exists  ready  formed  in  essential  oil  of  styrax.  It  is 
also  formed  by  decomposition  of  cinnamic  acid  (p.  402),  or,  syn- 
thetically, by  the  action  of  a  red  heat  upon  pure  acetylene,  a  mixture 
of  acetylene  and  benzene,  or  a  mixture  of  benzene  and  ethylene.  It 
is  a  colorless  liquid,  has  a  penetrating  odor,  recalling  those  of  ben- 
zene and  naphthalene,  and  a  peppery  taste ;  boils  at  143°  (289.4°  F.) ; 
soluble  in  all  proportions  in  alcohol  and  water  ;  neutral  in  reaction. 

Phenyl-acetylene — Acetenyl  -  benzene  —  CeHs.  C  :  CH — is  formed 
by  heating  acetophenone  chlorid  with  KHO  in  alcoholic  solution.  It 
is  a  colorless  liquid,  of  an  aromatic  odor,  boils  at  140°  (284° F.). 


HALOID    DERIVATIVES. 

By  the  substitution  of  atoms  of  Cl,  Br  and  I  for  the  hydrogen  of 
the  principal  and  lateral  chains  in  benzene  and  its  superior  homo- 
logues, a  great  number  of  subtances  are  obtained,  many  of  them 
forming  isomeric  groups. 

The  chlorin  derivatives  of  benzene  are  : 

Monochloro  -  benzene— C6H5C1— liquid;  boils  at  132°  (269. 6°  F.); 
sp.  gr.  1.128  at  0°;  obtained  by  the  action  of  Cl  upon  C6H6  in  the 
cold,  in  the  presence  of  a  little  I. 

Orthodichloro- benzene— 1—2— liquid;  boils  at  179°  (354.2°  F.); 
sp.  gr.  1.328  at  0°;  obtained  by  the  action  of  Cl  on  C6H6. 

Metadichloro- benzene— 1—3— liquid;  boils  at  172°  (341.6°  F.) ; 
sp.  gr.  1.307  at  0°;  obtainable  indirectly. 

Paradichloro- benzene — 1 — 4 — crystalline;  fuses  at  56.4°  (133.5° 


388  MANUAL    OF    CHEMISTRY 

F.) ;  boils  at  170°  (343.4°  F.) ;  is  the  principal  product  of  the  action 
of  Cl  on  C6H6  in  presence  of  I. 

Metatrichloro- benzene— 1—2— 4— crystals  ;  fuses  at  17°  (62.6° 
F.);  boils  at  213°  (415.4°  F.). 

Paratrichloro- benzene— 1—3— 5— crystals;  fuses  at  63.4°  (146.1° 
F.);  boils  at  208°  (406.4°  F.). 

Tetrachloro- benzene— 1—2— 3— 5— crystals;  fuses  at  50°  (122° 
F.);  boils  at  246°  (474.8° F.). 

Tetrachloro -benzene — 1 — 2 — 4 — 5 — crystals  ;  fuses  at  137° 
(278.6°  F.);  boils  between  243°-246°  (469.4°-474.8°  F.). 

Benzyl  chlorid— C6H5.CH2C1 — is  an  example  of  the  substitution 
of  a  halogen  in  the  lateral  chain  of  a  superior  homologue  of  benzene. 
It  is  obtained  by  the  action  of  chlorin  upon  boiling  toluene;  or  of 
PCh  on  benzylic  alcohol.  It  is  a  colorless  liquid,  boils  at  176°  (348.8° 
F.),  and  gives  off  pungent  vapors  which  excite  the  lachrymal  secre- 
tion. It  is  readily  oxidized  to  benzoic  aldehyde  or  benzoic  acid,  and 
serves  for  the  introduction  of  the  radical  benzyl  into  other  molecules. 
The  radical  of  benzylic  alcohol  (C6H5.CH2),  (p  397)  is  called  benzyl; 
that  of  benzoic  acid,  (C6H5.CO),  benzoyl  (p.  401). 


BENZENIC   OXYGEN   COMPOUNDS. 

The  derivatives  of  benzene  containing  oxygen  include,  besides 
alcohols,  aldehydes,  ketones,  acids,  ethers,  and  anhydrids,  cor- 
responding to  those  of  the  open  chain  series,  a  class  of  hydroxids, 
the  phenols,  of  which  there  are  no  aliphatic  prototypes. 

PHENOLS. 

In  the  phenols  the  hydroxyl  is  substituted  for  the  hydrogen  of  the 
benzene  ring,  while  in  the  alcohols  the  substitution  occurs  in  a  lateral 
chain.  Thus  phenol  is  C6H5.OH;  benzylic  alcohol,  C6H5.CH2OH. 
All  six  of  the  hydrogen  atoms  of  benzene  may  be  thus  replaced  to 
form  monohydric  phenols,  dihydric  phenols,  etc. 

In  their  properties  the  phenols  differ  from  the  alcohols  by  more 
nearly  approaching  the  character  of  the  acids.  On  oxidation  they  do 
not  furnish  aldehydes  or  acids;  they  do  not  divide  into  water  and 
hydrocarbon  under  the  influence  of  dehydrating  agents  ;  they  do  not 
react  with  acids  to  form  esters?  they  combine  directly  with  Cl  and  Br 
to  form  products  of  substitution ;  they  form  with  the  metallic  elements 
compounds  more  stable  than  similar  compounds  of  the  true  alcohols. 

The  phenols  occur  in  nature  in  small  quantities  only;  some  in  the 
vegetable  world,  and  some  in  combination  as  ester  sult'uric  acids  in 


PHENOLS  389 

the  urine.     They  are  mostly  products  of  distillation  of  wood,  coal, 
etc. 

MONOATOMIC  —  MONOHYDEIC    PHENOLS. 

The  monoatomic  phenols  are  produced:  (1)  by  fusing  the  cor- 
responding sulfonic  acids  with  caustic  alkali  :  CeHs.SOsK+KHO^ 
CeHs.OH-J-K^SOs;  (2)  by  decomposition  of  the  diazo-  compounds  (p. 
427)  by  boiling  with  water:  C6H5.N:N.HSO4+H20=C6H5.OH-f  N2+ 
H2SO4;  (3)  the  higher  phenols  are  produced  by  heating  phenol  with 
ZnCl2  and  the  alcohols,  a  phenolic  ether  being  also  formed.  Thus 
phenol  and  methylic  alcohol  yield  cresol  and  methyl  -phenyl  ether  : 


The  phenols  are  reduced  to  hydrocarbons  by  heating  with  zinc 
dust.  Their  ring  -hydrogen  is  readily  replaceable  by  other  elements 
or  groups  to  form  haloid,  nitro,  amido  derivatives,  etc.  Their  hy- 
droxyl  hydrogen  is  also  readily  replaceable  by  alkyls  to  produce 
ethers,  by  Na,  K,  and  Ca  to  produce  phenates,  and  by  acidyls  to  pro- 
duce phenyl  esters  (p.  391).  The  phenols  combine  with  the  diazo 
compounds  to  produce  azo-  and  diazo  dyes,  and  with  phthalic  acid 
to  produce  phthalems. 

Phenol  —  Benzophenol  —  Phenyl  Jiydroxid  —  Phenic  acid  —  Carbolic 
acid  —  CeHs.OH  —  exists  in  considerable  quantity  in  coal-  and  wood- 
tar,  and  in  small  quantity  in  castoreum  and,  in  combination,  in  the 
urine.  It  is  produced  in  the  intestine. 

It  is  formed  :  (1)  by  fusing  sodium  -phenyl  sulfid  with  excess  of 
alkali:  C6H5.NaS+NaHO=C6H5.OH-hNa2S;  (2)  by  heating  phenyl 
iodid  and  potassium  hydroxid  at  320°  (608°  F.):  C6H5I+KHO= 
CeHs.OH+KI;  (3)  by  heating  together  salicylic  acid  and  quicklime; 
C6H4.OH.COOH+CaH2O2=C6H5.OH  +  CaCO3+H2O;  (4)  by  total 
synthesis  from  acetylene,  through  benzene  (p.  378),  and  its  sulfonic 
acid;  (5)  by  decomposition  of  the  phenylic  esters  by  alkalies.  Thus 
salol  yields  phenol  and  salicylic  acid:  C6H4.OH.COO(C6H5)+KHO= 
C6H5.OH-j-C6H4.0H.COOK  ;  (6)  by  dry  distillation  of  benzoin. 
"Synthetic  phenol,"  prepared  by  method  (4),  is  now  manufactured. 
"Carbolic  acid"  is  obtained  from  the  "middle  oil"  of  gas  tar  (p.  385). 
It  is  purified  by  conversion  into  potassium  phenate,  CeHs.OK,  which 
is  crystallized,  decomposed  by  HC1,  and  the  liberated  phenol  recrys- 
tallized  and  distilled. 

Phenol  is  extensively  used,  not  only  as  an  antiseptic,  but  also  in 
the  manufacture  of  numerous  derivatives,  including  medicinal  com- 
pounds, dyes  and  explosives. 

Phenol  crystallizes  in  long,  colorless  needles,  fuses  at  43°  (109.4° 
F.),  boils  at  183°  (361.4°F.),  sp.  gr.  1.084  at  0°  (32°  F.),  has  a 
characteristic  odor,  and  an  acrid,  burning  taste,  soluble  in  15  parts 


390  MANUAL    OP    CHEMISTRY 

of  water  at  20°  (68°  F.),  very  soluble  iu  alcohol  and  in  ether,  neutral 
in  reaction.     It  may  be  distilled  without  decomposition. 

Its  vapor  is  reduced  to  benzene  by  heating  with  Zn.  It  combines 
with  H2SO4  to  form  o-,  and  p- phenol  sulfonic  acids.  With  HNOs  it 
forms  2-4-6 -trinitro phenol.  Heated  with  sulfuric  and  oxalic  or 
arsenic  acid,  it  yields  several  triphenyl- methane  dyes,  among  which 
are  corallin,  rosolic  acid,  peonin,  azulin,  aurin,  and  phenicin. 

Analytical  Characters — (1)  Its  peculiar  odor.  (2)  Mix  with  one 
quarter  volume  of  NH^HO;  add  two  drops  of  sodium  hypochlorite 
solution,  and  warm:  a  blue  or  green  color.  Add  HC1  to  acid  reac- 
tion: turns  red.  (3)  Add  two  drops  of  the  liquid  to  a  little  HC1, 
and  then  a  drop  of  HNOa:  a  purple  red  color.  (4)  Boil  with  HNOa 
so  long  as  red  fumes  are  given  off ,  neutralize  with  KHO :  a  yellow, 
crystalline  precipitate.  (5)  Float  the  liquid  on  H2SO4,  add  pow- 
dered KNO3:  a  violet  color.  (6)  With  solution  of  FeS04:  a  lilac 
color.  (7)  Add  excess  of  bromin  water:  a  yellowish -white  precipi- 
tate. This  compound,  tribromophenol,  CeEbBraOH,  is  the  form  in 
which  phenol  is  quantitatively  determined;  100  parts  of  it  correspond 
to  29.8  parts  of  phenol.  (8)  Moisten  a  pine  shaving  with  the  liquid, 
then  with  HC1,  to  which  a  trace  of  KClOa  has  been  added  immedi- 
ately before  use,  and  expose  to  sunlight:  a  fine  blue  color.  The  test 
should  be  tried  also  with  a  solution  of  phenol,  and  with  the  acid 
alone,  as  only  certain  varieties  of  pine  are  suitable.  (Pine -shaving 
reaction.  See  also  Pyrrole.) 

Toxicology. — Carbolic  acid  is  an  active  poison  and  corrosive.  It 
has  caused  death  in  a  dose  of  1.5  gram.  The  average  duration  of 
fatal  cases  is  2-8  hours.  Death  may  occur  in  3-5  minutes  from  col- 
lapse. It  causes  a  burning  sensation,  soon  followed  by  intense  pain 
and  cauterization  of  all  parts  with  which  it  comes  in  contact.  The 
stain  which  it  produces  is  at  first  white,  after  a  few  minutes;  later  it 
turns  darker  and,  when  the  eschar  separates,  a  brown  stain  remains, 
which  persists  for  many  days.  Vomiting  usually  occurs,  the  vomited 
matters,  as  well  as  the  breath,  having  the  odor  of  carbolic  acid.  The 
patient  soon  becomes  unconscious,  and  death  is  from  collapse  or  in 
coma.  The  urine,  normal  in  color  when  first  voided,  soon  becomes 
olive -green,  brown,  or  even  black  in  color,  The  treatment  consists 
in  administration  of  albumen,  saccharated  lime,  sodium  sulfate,  or 
strong  alcohol,  followed  by  lavage. 

Phenates. — Carbolates. — The  oxhydryl  hydrogen  of  phenol  is  re- 
placeable by  certain  metals  and  by  alkyls  to  form  phenates  and 
phenyl  ethers.  When  phenol  and  KHO  are  heated  together,  potas- 
sium phenate,  CeHsOK,  is  formed.  This,  when  treated  in  alcoholic 
solution  with  HgCh,  produces  mercuric  phenate,  (CeHsOhHg,  a 
yellow,  crystalline  solid  which  has  been  used  in  medicine. 


PHENOLS  391 

The  phenyl  ethers  are  formed  by  heating  the  metallic  phenates 
with  the  alkyl  haloids:  CeHs.O.K+CHal^CeHs.O.CHa+KI,  as  the 
aliphatic  ethers  are  produced  from  the  alkyl  haloids  and  the  metallic 
alcoholates  (p.  299).  They  are  to  be  regarded  as  simple  ethers, 
rather  than  as  phenates  (see  also  sodium  ethylate,  p.  244,  and  Gluco- 
sids,  p.  409).  The  phenyl  esters,  on  the  other  hand,  are  formed  by 
the  action  of  the  acidyl  chlorids  upon  the  phenols,  or  upon  their 
metallic  derivatives:  C6H5.OH+CH3.COC1=  CHs.CO^Hs+HCl,  or, 
C6H5.OK  +  CH3.COC1  =  CH3.CO2.C6H5+KC1,  as  the  aliphatic  esters 
are  formed  by  the  action  of  acidyl  haloids  upon  the  alcohols  or  upon 
the  alcoholates  (p.  312). 

Methyl-phenyl  Ether  —  Anisol  —  Cells. OCHs — is  a  colorless,  thin 
liquid,  boils  at  152°  (305.6°  F.)  without  decomposition.  Sulfuric  acid 
dissolves  it,  with  formation  of  methyl -phenol  sulfonic  acid. 

Ethyl-phenyl  Ether — Phenetol — Cells. OC2H5 — is  a  colorless  liquid, 
having  an  aromatic  odor.  It  boils  at  172°  (341.6°  F.). 

Anisol  and  phenetol  serve  as  the  starting-points  for  the  produc- 
tion of  the  anisidins  and  phenetidins  (p.  423). 

Cresols — Cresylols — Cresylic  acids — Benzylic  or  cresylic  phe- 

/  r\\i 

nols — CeH^Qjj3 — 108. — Of  the  three  possible  compounds,  two,  the 

para  and  ortho,  accompany  phenol  in  coal-tar,  from  which  they  may 
be  separated  by  fractional  distillation.  They  are  more  readily  ob- 
tained pure  from  toluene. 

Orthocresol  (1 — 2)  is  a  crystalline  solid,  fusible  at  31°-31.5° 
(87.8°-88.7°  F.),  which  assumes  a  blue  color  with  ferric  chlorid. 

Metacresol  (1 — 3)  is  obtainable  by  the  action  of  P205  on  thy- 
mol. It  is  a  colorless  liquid,  whose  odor  resembles  that  of  phenol.  It 
boils  at  201°  (393.8°  P.),  and  does  not  solidify  at  —75°  (—103°  F.). 

Paracresol  (1—4)  is  a  crystalline  solid,  fusible  at  36°  (96.8°  F.), 
boiling  at  198°  (388.4°  F.),  having  a  phenol-like  odor;  colored  blue 
by  ferric  chlorid.  Creolin — an  antiseptic  less  poisonous  than  phenol, 
consists  chiefly  of  cresols.  Lysol  is  impure  paracresol,  mixed  with 
fat  and  saponified. 

Creasote  —  Creasotum  (U.  S.)  —  is  a  complex  mixture  containing 
phenol,  cresol,  creasol,  C8Hi0O2,  guaiacol,  C7H8O2  (see.  pyrocatechol), 
and  other  substances,  obtained  from  wood -tar,  and  formerly  extensively 
used  as  an  antiseptic.  It  is  an  oily  liquid,  colorless  when  freshly 
prepared,  but  becoming  brownish  on  exposure  to  light.  It  has  a  burn- 
ing taste  and  a  strong,  peculiar  odor.  It  boils  at  203°  (397.4°  F.), 
and  does  not  solidify  at  —27°  (—16.6°  F.). 

Xenols— Xylenols.— Theoretically  there  are  six  possible  xenols 
which  are  dimethyl  phenols,  CeHaCCHshOH  ;  two  derivable  from 
orthoxylene,  three  from  metaxylene  and  one  from  paraxylene.  They 


392  MANUAL    OF    CHEMISTRY 

have  all  been  produced  synthetically.  There  are  also  three  possible 
xenols  which  are  ethyl  phenols,  CeELi^H^OH. 

Thymol — 3-Methyl-6-isopropyl  phenol — Cymylic  phenol — CeHa- 
(CH3)(3)(C3H7)(6), — exists,  accompanying  cyraene  andthymene, 
in  essence  of  thyme,  from  which  it  is  obtained.  It  is  also 
prepared  synthetically  from  cuminic  aldehyde,  CoH^CHO^i^CsHrJu). 

It  crystallizes  in  large,  transparent,  rhombohedral  tables;  has  a 
peppery  taste,  and  an  agreeable,  aromatic  odor.  It  fuses  at  44°  (111.2° 
F.),  and  boils  at  230°  (446°  F.);  is  sparingly  soluble  in  water,  very 
soluble  in  alcohol  and  ether.  With  the  alkalies  it  forms  definite  com- 
pounds, which  are  very  soluble  in  water.  Its  reactions  are  very  sim- 
ilar to  those  of  phenol. 

Thymol  is  an  excellent  deodorizing  and  antiseptic  agent,  possess- 
ing the  advantage  over  phenol  of  having  itself  a  pleasant  odor. 

Aristol  is  diiodo-thymol,  a  dibenzenic  compound,  produced  by  the 
action  of  a  solution  of  I  in  KI  upon  an  aqueous  solution  of  thymol  in 
the  presence  of  KHO.  It  is  an  inodorous,  yellowish -red  powder, 
insoluble  in  H2O,  very  sparingly  soluble  in  alcohol,  readily  soluble  in 
ether  and  in  chloroform.  It  is  decomposed  by  heat  and  by  light  and 
is  said  to  be  a  non- poisonous  antiseptic. 

Carvacrol— 2-Methyl  -  5-isopropyl  phenol  —  C6H3  ( OH )  (I)  ( CH3 )  (a)- 
(CsHyXs) — an  isomere  of  thymol,  exists  in  many  essential  oils,  and  is 
obtained  by  the  action  of  iodin  upon  camphor;  by  the  action  of  pot- 
ash in  fusion  upon  cymene  sulfonic  acid,  CioHiaSOsH;  or  by  a 
transposition  of  the  atoms  of  another  isomere,  carvol,  which  exists  in 
caraway  oil.  It  is  an  oil,  boiling  at  233°-235°  (451.4°-455°  F.). 
Heated  with  P2O§,  it  yields  orthocresol. 


SUBSTITUTED    PHENOLS. 

Phenol  is  a  monosubstituted  derivative,  and  hence  still  contains 
five  H  atoms  which  may  be  replaced  by  other  elements  or  radicals,  to 
produce  di-  or  tri-  or  poly -substituted  derivatives  of  benzene,  which 
will  be  ortho,  meta  or  para,  etc.,  according  to  the  relations  of  the 
introduced  groups  to  the  OH,  already  existing  in  phenol,  or  to  the 
C*H.2n+i  and  OH  groups  in  its  superior  homologues. 

Chlorophenols. — The  three  monochlorinated  compounds  are  ob- 
tainable from  the  corresponding  chloranilins.  Orthochlorophenol 
(1—2)  is  a  colorless  liquid,  boils  at  175°-176°  (347°-348.8°  F.), 
converted  into  pyrocatechol  by  KHO.  Metachlorophenol  (1 — 3)  is  a 
liquid,  boiling  at  214°  (417.2°  F.) .  KHO  converts  it  into  resorcinol. 
Parachlorophenol  (1—4)  is  a  crystalline  solid,  fusible  at  37°  (98.6° 
F.),  converted  into  quinol  by  fusion  with  KHO.  Di-,  tri-,  and 
penta- chlorophenols  are  also  known. 


PHENOLS  393 

Bromophenols  correspond  in  method  of  formation  and  properties 
with  the  Cl  derivatives.  2-4-6  Tribromophenol — CeH2.OH.Br3 — is 
the  precipitate  formed  on  adding  bromin  water  to  phenol  solution.  It 
forms  white  crystals,  fusing  at  92°  (197. 6°  F.),  insoluble  in  water, 
soluble  in  alcohol  and  ether.  It  is  used  as  an  antiseptic  in  diphtheria 
under  the  name  Bromol.  Paramonochlorophenol  and  orthomono- 
bromophenol  have  been  used  for  the  same  purpose. 

lodophenols  are  formed  by  the  action  of  iodin  and  K2S  upon 
phenol  in  the  presence  of  excess  of  alkali,  or  from  the  corresponding 
amidophenols.  Like  the  chlorin  and  bromin  derivatives,  they  yield 
the  corresponding  diphenol  by  the  action  of  KHO  in  fusion.  A  tri- 
iodophenol,  formed  by  the  action  of  solution  of  I  in  K2S  upon  an 
alkaline  solution  of  phenol,  has  been  proposed  as  a  substitute  for 
iodoform  under  the  name  annidalin.  (See  also  pp.  404,  409,  418.) 

DIATOMIC,    OR    DIHYDRIC    PHENOLS. 

Diatomic  phenols  are  derived  from  the  benzenic  hydrocarbons  by 
the  substitution  of  two  (OH)  groups  for  two  atoms  of  hydrogen. 
In  obedience  to  the  laws  of  substitution  already  discussed,  three 
such  compounds  exist,  corresponding  to  each  hydrocarbon. 

Pyrocatechol — Pyrocatechin —  Oxyphenic  acid —  Orthodioxy  -  benzene 
— CeH^OHhd.so  is  obtained  from  catechin  or  from  morintannic  acid 
by  dry  distillation;  also  by  the  action  of  KHO  on  orthochlor-  or 
orthoiodo-phenol,  or  by  decomposing  its  methyl  ether,  guaiacol,  by  HI 
at  200°  (392°  F.).  It  crystallizes  in  short,  square  prisms;  fuses  at 
104°  (219. 2°  F.),  and  boils  at  245.5°  (473.9°  F.).  Readily  soluble 
in  water,  alcohol,  and  ether.  Its  aqueous  solution  gives  a  dark  green 
color  with  Fe2Cle  solution,  changing  to  violet  on  addition  of  NH-tHO, 
NaHCOa,  or  tartaric  acid.  Its  acid  sulfuric  ester  exists  in  the  urine. 

Monomethyl  -  pyrocatechuic  Ether — Guaiacol  —  CeH^OH.- 
(OCHs)(2) — exists  in  beech-wood  tar,  from  which  an  impure  (60-90%) 
guaiacol  is  obtained  as  a  yellowish  liquid,  sp.  gr.  1.133,  boiling  at 
206°-207°,  by  distillation.  Pure  guaiacol  is  obtained  from  this  by 
crystallization  at  low  temperature;  by  heating  pyrocatechol  with  potas- 
sium-methyl sulfate  and  KHO;  also  from  vanillin  (p.  399),  and  from 
veratrol.  It  is  a  crystalline  solid,  fuses  at  33°  (91.4°  F.),  boils  at  205° 
(401°  F. ) ,  soluble  in  50  parts  of  water.  Guaiacol  is  used  in  the  treat- 
ment of  phthisis  both  on  account  of  its  germicidal  action,  and  upon  the 
theory  that  it  forms  compounds  with  the  toxalbuinins  (q.  v.),  which 
are  readily  eliminated.  It  is  also  used  in  numerous  forms  of  combi- 
nation :  in  its  carbonic  esters,  as  styracol=cinnamyl- guaiacol,  as 
benzosol=benzoyl- guaiacol,  as  thiocol— guaiacol- potassium  sulfon- 
ate,  and  in  combination  with  salicylic  acid. 


394  MANUAL    OF    CHEMISTRY 

Dimethyl-pyrocatechuic  Ether  — Veratrol  —  CeHt  ( OCHa )  211-2)  —  is 
an  oil,  crystallizing  at  15°  (59°  F.),  formed  by  distilling  veratric 
acid  (p.  405),  or  by  acting  upon  the  potassium  salt  of  guaiacol  with 
methyl  iodid. 

Resorcinol  —  Eesorcin  —  Metadioxy  -  benzene — CeEU  ( 0  H )  a  (i,  3)  is  ob- 
tained by  the  action  of  fused  KHO  on  metachlor-  or  iodophenol. 
It  is  also  prepared  by  dry  distillation  of  extract  of  Brazil  wood. 

It  forms  ^short,  thick,  colorless  and  odorless,  rhombic  prisms. 
Fuses  at  104°  (219.2°  F.),  and  boils  at  271°  (519.8°  F.).  It  is  very 
soluble  in  water,  alcohol,  and  ether.  Its  aqueous  solution  is  neutral 
in  reaction,  and  intensely  sweet.  With  Fe2Cle  its  solutions  assume  a 
dark -violet  color,  which  is  discharged  by  NELiHO.  Its  ammoniacal 
solution,  by  exposure  to  air,  assumes  a  pink  color,  changing  to  brown 
and,  on  evaporation,  green  and  dark  blue.  Heated  with  phthalic 
anhydrid  at  195°  (383°  F.)  it  yields  fluorescein  (p.  396).  It  dis- 
solves in  fuming  H2SO4,  forming  an  orange -red  solution,  which  be- 
comes darker,  changes  to  greenish -black,  then  to  pure  blue,  and 
finally  to  purple  on  being  warmed. 

Resorcinol,  heated  with  sodium  nitrite  and  H20  to  about  150° 
(302°  F.)  yields  a  blue  pigment  known  as  lacmoid,  which  behaves 
like  litmus  with  acids  and  alkalies,  but  is  more  sensitive. 

Quinol  —  Hydroquinone  —  Paradioxy -benzene  —  C6H4(OH)2U, 4>  is 
formed  by  fusing  paraiodo- phenol  with  KHO  at  180°  (356°  F.), 
by  dry  distillation  of  oxysalicylic  acid  or  of  quinic  acid,  and  by  the 
action  of  reducing  agents  on  quinone.  It  forms  colorless,  rhombic 
prisms,  which  fuse  at  169°  (336.2°  F.).  Readily  soluble  in  water, 
alcohol,  or  ether.  Its  aqueous  solution  is  turned  red -brown  by  NHr 
HO.  Oxidizing  agents  convert  it  into  quinone. 

Orsinol —  Or  sin — Dimetadioxy  toluene — C6H3  ( CH3 )  (o  ( OH )  (3)  ( OH )  (s) 
— a  homologue  of  resorcinol,  exists  in  nature  in  those  lichens  which  are 
used  as  sources  of  archil  and  litmus  (Rocella  tinctoria,  etc.).  It  crys- 
tallizes in  six-sided  prisms;  is  sweet;  readily  soluble  in  water,  alco- 
hol, or  ether;  fuses  at  58°  (136.4°  F.).  Its  aqueous  solution  is  col- 
ored violet -blue  by  Fe2Cle.  It  unites  with  NHs  to  form  a  compound 
which  absorbs  O  from  the  air,  and  is  converted  into  orcein,  C7H7- 
NOs;  a  dark -red  or  purple  body,  which  is  the  chief  constituent  of  the 
dye-stuff  known  as  archil,  cudbear,  French  purple,  and  litmus. 


TRIATOMIC,    OR    TRIHYDRIC    PHENOLS. 


Phloroglucin  —  CeHsfOHJsd.g.g)  —  is  obtained  by  the  action  of 
potash  upon  phloretin,  quercitrin,  maclurin  (see  Glucosids),  catechin, 
kino,  etc.  It  crystallizes  in  rhombic  prisms,  containing  2Aq;  is  very 
sweet;  and  very  soluble  in  water,  alcohol,  and  ether. 


PHENOLS  395 

Pyrogallol — Pyrogallic  acid  —  CeHsf  OH)  3(1,2.3) — is  formed  when 
gallic  acid  (p.  406)  is  heated  to  200°  (392°  F.).  It  crystallizes  in 
white  needles;  neutral  in  reaction ;  very  soluble  in  water;  very 
bitter;  fuses  at  132°  (238°F.);  boils  at  210°  (410°F.);  poisonous. 
Its  most  valuable  property  is  that  of  absorbing  oxygen,  for  which 
purpose  it  is  used  in  the  laboratory  in  the  form  of  a  solution  of 
potassium  pyrogallate. 

When  pyrogallol  is  heated  with  half  its  weight  of  phthalic  an- 
hydrid  for  several  hours  at  190°-200°  (374°-392°  F.)  it  yields  pyro- 
gallol phthalein,  or  gallein,  a  brown -red  powder  (or  green  crystals) 
which  dissolves  with  a  brown  color  in  neutral  solutions,  the  color 
changing  to  red  with  a  faint  excess  of  alkali. 

Oxyhydroquinone — C6H3(OH)3(i,2,4) — is  produced  by  fusing  qui- 
none  with  KHO.  It  is  crystalline,  fuses  at  140°  (284°  F.),  very 
soluble  in  water  and  in  ether. 


UNSATURATED    PHENOLS. 

These  are  derived  from  the  benzenic  hydrocarbons  with  unsatu- 
rated  lateral  chains  (p.  387).  Olefin  monoxybenzenes,  dioxyben- 
zenes,  trioxybenzenes,  and  a  tetroxybenzene  are  known.  They  are 
aromatic  oils  of  high  boiling  points,  many  derived  from  various 
plants.  Included  in  this  class  are:  Chavicol,  p- Allyl  phenol — CeH4- 
OH.(CH2.CH:CH2)(4) — occurs  in  an  oil  from  certain  peppers.  Its 
isornere,  p-Propenyl  phenol,  C6H4.OH.(CH:CH.CH3)(4),  is  p-anol, 
whose  methylic  ether,  C6H4.O(CH3).(CH:CH.CH3)(4),  p-propenyl 
anisol,  or  anethol,  exists  in  the  oils  of  anise,  estragon  and  fennel. 
Among  the  diphenols  is  eugenol,  C6H3.(CH2.CH:CH2)(i)(OCH3)(3)- 
(OH)(4),  allyl  3-4-guaiacol,  an  essential  oil  from  pimenta,  eugenia, 
and  certain  peppers.  The  corresponding  dimethyl  compound  exists 
in  bay-oil.  Safrol,  Allyl  3-4  pyrocatechol  methylene  ether,  CTfo:- 

CH.CH2\       \_o/(H2>  is  present  in  oil  of   sassafras,  and   oil   of 

Illicium.     Apiol,  from  oil  of  parsley,  is  a  complex  methylene  ether, 
corresponding  to  allyl  tetraoxybenzene,  C6H.(OH)4.CH2.CH:CH2. 


PHENOL    DYES. 

Aurin — CigHuOs,  and  Rosolic  acid — C2oHi6O3 — are  substances  ex- 
isting in  the  dye  obtained  by  the  action  of  oxalic  acid  upon  phenol  in 
presence  of  H2SO4,  known  as  corallin,  or  poeonin,  which  communi- 
cates to  silk  or  wool  a  fine  yellow -red  color. 

Aurin  crystallizes  in  fine,  red  needles  from  its  solution  in  HC1. 


396  MANUAL    OP    CHEMISTRY 

It  is  insoluble  in  H20,  but  soluble  in  HC1,  alcohol,  and  glacial  acetic 
acid.  It  forms  a  colorless  compound  with  potassium  bisulfite. 

Phthaleins.  —  These  substances  are  produced  by  heating  the  phe- 
nols with  phthalic  anhydrid,  CeH^COhO,  water  being  at  the  same 
time  eliminated. 

Their  constitution  is  that  of  a  benzene  nucleus,  two  of  whose  H 
atoms  have  been  replaced  by  two  acetone  groups  (CO),  whose  remain- 
ing valences  attach  them  to  two  phenol  groups  by  exchange  with  an 
atom  of  hydrogen  (see  p.  449). 

Thus  phenol-phthalein,  the  simplest  of  the  group,  has  the  con- 

stitution, CeHX^Qo—  CeH^OH)!  Phenol-phthalein  is  a  yellow,  crys- 
talline powder,  insoluble  in  water,  but  soluble  in  alcohol.  Its  alco- 
holic solution,  perfectly  colorless  if  neutral,  assumes  a  brilliant  ma- 
genta-red in  the  presence  of  an  alkali.  This  property  renders 
phenol-phthalein  very  valuable  as  an  indicator  of  reaction. 

Resorcinol-phthalein  —  Fluorescein  —  C2oHi2O5  —  bears  the  same 
relation  to  resorcinol  that  phenol-phthalein  does  to  phenol,  and  is 
obtained  from  resorcinol  by  a  corresponding  method.  It  is  a  dark- 
brown  crystalline  powder,  which  dissolves  in  ammonia  to  form  a  red 
solution,  exhibiting  a  most  brilliant  green  fluorescence.  A  tetra- 
bromo-derivative  of  fluorescein  is  used  as  a  dye  under  the  name 
eosin. 

QUINONES. 

The  quinones  are  benzene  derivatives  in  which  two  atoms  of 
hydrogen  are  replaced  by  two  oxygen  atoms.  The  attachment  of 
the  -O.O-  group  is  either  ortho-  or  para-,  never  meta-.  Ortho- 
quinones  of  the  polybenzenic  series,  such  as  ft  naphthoquinone  and 
anthraquinone  (p.  444),  are  well-known  compounds,  but  the  mono- 
benzenic  ortho  -  quinones  are  only  known  in  their  derivatives. 

The  monobenzenic  para-quinones  may  be  considered  either  as 
peroxids,  the  bonds  of  the  benzene  ring  remaining  intact  (Formula  I), 

or  they  may  be  considered  as  ring- 
O  ke  tones    (Formula   II),    in   which 

Q  the  two  CO  groups  form  a  part  of 

/  \  an    oxidized    hydroaromatic    ring 

^        ^JH         (p.  431).     The  former  view  is  fa- 
HC        CH         vored   by  the  facts  that  the  qui- 


H 


I 


Y 

o 


\/  nones  are  strong  oxidizing  agents, 

II  as   are   the    peroxids   in    general, 

O  and   that   they   yield   monosubsti- 

tuted   derivatives    by  replacement 
of  their  oxygen  by  univalents,  as  benzoquinone-  forms  p-dioxyben- 


QUINONES  397 

zene,  (HO)CcH.:CHC(OH)  on  reduction,  and  p-dichlorobenzene, 


C1C\CH.:CH^CC1»  bv  the  action  of  pcis-  On  the  other  hand,  the 
existence  of  the  CO=  group  in  the  quinones  is  indicated  by  the 
fact  that  they  readily  form  oxims  with  hydroxylamin,  a  reaction 
characteristic  of  compounds  containing  CO=  (p.  256),  as  benzo- 

/  r\  FT  .  /"1TT\ 

quinone  forms  quinone  dioxim,  HO.NC\CH'CH/CN.OH;   and  if,  by 

reason  of  its  oxidation  of  phenylhydrazin,  benzoquinone  forms  no 
phenylhydrazone  (p.  429)  such  compounds  are  formed  by  the  naph- 
thoquinones. 

The  quinones  form  a  number  of  derivatives,  by  the  introduction 
of  alkyl,  halogen,  amido-,  nitro,  etc.,  groups  for  their  hydrogen  or 
oxygen.  Among  these  are  the  anils,  formed  by  substitution  of 
=N.C6Hs  for  O,  from  which,  in  turn,  an  important  series  of  blue 
and  green  dyes,  the  indoanilin  or  indulin  dyes  are  derived. 

/° 

Quinone  —  Benzoquinone  —  CeELi  \\\  —  is  formed  by  the  action 

of  oxidants  upon  a  variety  of  p-  benzene  derivatives,  but  best  by 
limited  oxidation  of  quinic  acid.  It  crystallizes  in  golden-yellow 
prisms,  f  .  p.  116°  (240.8°  F.),  sublimes  at  ordinary  temperatures, 
sparingly  soluble  in  cold  water,  readily  soluble  in  hot  water,  alcohol 
and  ether.  It  has  a  peculiar,  pungent  odor,  stimulates  the  lachrymal 
secretion,  and  irritates  the  skin.  Reducing  agents  convert  it  into 
quinol. 

AROMATIC    ALCOHOLS. 

The  alcohols  (p.  239)  corresponding  to  this  series  of  hydrocarbons 
are  isomericwith  the  phenols.  They  con  tain  the  characterizing  group 
of  the  primary  alcohols,  CEbOH;  once  if  the  alcohol  be  monoatomic, 
twice  if  diatomic,  etc.,  and  they  yield  on  oxidation,  first  an  aldehyde 
and  then  an  acid.  Thus:  C6H5.CH2OH  =  benzylic  alcohol;  CeH^.- 
CHO  =  benzoic  aldehyde;  C6H5.COOH  =  benzoic  acid. 

They  are  capable  of  yielding  isomeric  products  of  further  sub- 
stitution, ortho,  para,  or  meta. 

Benzylic  Alcohol  —  Benzoic  Alcohol  —  Benzyl  Hydrate—  CeHs.- 
CEbOH  —  does  not  exist  in  nature,  and  is  of  interest  chiefly  as 
corresponding  to  two  important  compounds,  benzoic  acid  and 
benzoic  aldehyde  (oil  of  bitter  almonds)  .  It  is  obtained  by  the  action 
of  potassium  hydroxid  upon  oil  of  bitter  almonds,  or  by  slowly 
adding  sodium  amalgam  to  a  boiling  solution  of  benzoic  acid. 

It  is  a  colorless  liquid;  boils  at  206.5°  (403.7°  F.);  has  an  aro- 
matic odor;  is  insoluble  in  water,  soluble  in  all  proportions  in  alcohol, 
ether,  and  carbon  disulfid.  By  oxidation  it  yields,  first,  benzoic 


398  MANUAL    OF    CHEMISTRY 

aldehyde,  C6H5.CHO  ;  and  afterward,  benzole  acid,  C6H5.COOH. 
By  the  same  means  it  may  be  made  to  yield  products  similar  to  those 
obtained  from  the  alcohols  of  the  saturated  hydrocarbons. 

Secondary  and  tertiary  aromatic  alcohols  are  also  known,  such 
as  phenyl-methyl  carbinol,  CeHs.CHOH.CHs,  and  phenyl-dimethyl 
carbinol,  C6H5.COH(CH3)2  (p.  240).  The  secondary  alcohols  yield 
ke tones  on  oxidation  (p.  400). 

Di-  and  tri-hydric  alcohols,  such  as  the  xylylene  glycols,  CeH-t- 
(CH2OH)2  (p.  251),  and  mesitylene  glycerol,  C6H3.(  CH2OH  )3<i,3.S), 
are  also  known,  as  well  as  alcohols  with  unsaturated  lateral 
chains,  such  as  cinnamic  alcohol,  CeHs.CHrCH.CH^OH,  which 
occurs  as  its  cinnamic  ester  in  storax.  It  oxidizes  to  cinnamic  alde- 
hyde (p.  399)  and  cinnamic  acid  (p.  402). 


ALPHENOLS,  OR  OXYPHENYL  ALCOHOLS. 

These  substances  are  intermediate  in  function  between  the  alcohols 
and  the  phenols,  and  contain  both  substituted  groups  OH  and 
CH2OH. 

Saligenin — o-Oxybenzylic  Alcohol — CeH^Qjj2     — is  obtained  from 

salicin  (p.  413)  in  large,  tabular  crystals;  quite  soluble  in  alcohol, 
water,  and  ether.  Oxidizing  agents  convert  it  into  salicylic  aldehyde, 
which  by  further  oxidation  yields  salicylic  acid.  It  is  also  formed 
by  the  action  of  nascent  hydrogen  on  salicylic  aldehyde. 

ALDEHYDES. 

The  aromatic  aldehydes  (p.  255)  are  the  first  products  of  oxidation 
of  the  aromatic  alcohols.  Monaldehydes  containing  one  CHO  group 
and  dialdehydes  containing  two  such  groups  are  known. 

The  monaldehydes  are  formed:  (1)  By  oxidation  of  the  alcohols; 
(2)  by  decomposition  of  the  alcohol  bichlorids  by  water:  CeHs.CHCh 
+  H20  =  C6H5.CHO  +  2HC1.  (3)  By  oxidation  of  the  alcohol  mono- 
chlorids  by  lead  nitrate:  C6H5.CH2C1  +  O  =  C6H5.CHO  +  HC1.  (4) 
By  the  action  of  chromyl  chlorid,  Cr02Cl2,  upon  the  hydrocarbons, 
and  decomposition  of  the  addition  compound  by  water. 

Benzoic  Aldehyde  —  Benzoyl  hydrid  —  CeHs.CHO  —  is  the  main 
constituent  of  oil  of  bitter  almonds,  although  it  does  not  exist  in 
in  the  almond  (see  p.  410).  It  is  formed,  along  with  hydrocyanic 
acid  and  glucose,  by  the  action  of  water  upon  amygdalin.  It  is 
also  formed  by  the  general  methods  given  above;  by  the  dehydration 
of  benzylic  alcohol ;  by  the  dry  distillation  of  a  mixture  in  molecular 
proportions  of  calcium  benzoate  and  formate;  by  the  action  of  nas- 


QUINONES  399 

cent  hydrogen  upon  benzoyl  cyanid,  etc.  It  is  obtained  from  bitter 
almonds.  The  crude  oil  contains,  besides  benzoic  aldehyde,  hydro- 
cyanic and  benzoic  acids  and  benzoyl  cyanid. 

It  is  a  colorless  oil,  having  an  acrid  taste  and  the  odor  of  bitter 
almonds;  sp.  gr.  1.050;  boils  at  179.4°  (354.9°  P.);  soluble  in  30 
parts  of  water,  and  in  all  proportions  in  alcohol  and  ether.  Oxidiz- 
ing agents  convert  it  into  benzoic  acid,  a  change  which  occurs  by 
mere  exposure  to  air.  Nascent  hydrogen  converts  it  into  benzylic 
alcohol.  With  Cl  and  Br  it  forms  benzoyl  chlorid  or  bromid.  H^SCU 
dissolves  it  when  heated,  forming  a  purple-red  color,  which  turns 
black  if  more  strongly  heated.  It  forms  a  series  of  products  of 
substitution,  haloid,  nitro,  amido,  etc. 

When  perfectly  pure,  benzoic  aldehyde  exerts  no  deleterious  action 
when  taken  internally;  owing,  however,  to  the  difficulty  of  com- 
pletely removing  the  hydrocyanic  acid,  the  substances  usually  sold  as 
oil  of  bitter  almonds,  ratafia,  and  almond  flavor,  are  almost  always 
poisonous,  if  taken  in  sufficient  quantity.  They  may  contain  as 
much  as  10-15  per  cent,  of  hydrocyanic  acid,  although  said  to  be 
"purified."  The  presence  of  the  poisonous  substances  may  be  de- 
tected by  the  tests  given  on  page  338. 

Salicylic  Aldehyde — Salicyl  hydrid — Salicylal — Salicylous  acid — 
o-Oxybenzaldehyde  —  CeH^OH)  (CHO)(2) —  exists  in  the  flowers  of 
Spircea  ulmaria,  and  is  the  principal  ingredient  of  the  essential  oil 
of  that  plant.  It  is  best  obtained  by  oxidizing  salicin  (p.  413). 

It  is  a  colorless  oil;  turns  red  on  exposure  to  air;  has  an  agree- 
able, aromatic  odor,  and  a  sharp,  burning  taste;  sp.  gr.  1.173  at 
13.5°  (56.3°  P.);  boils  at  196.5°  (385.7°  P.);  soluble  in  water, 
more  so  in  alcohol  and  in  ether. 

It  is,  as  we  should  suspect  from  its  origin,  a  substance  of  mixed 
function,  possessing  the  characteristic  properties  of  aldehyde  and 
phenol.  It  produces  a  great  number  of  derivatives,  some  of  which  are 
salts  or  esters,  such  as  p-methoxybenzaldehyde,  or  anisic  aldehyde, 
C6H4(CHO)(OCH3)(4),  a  product  of  oxidation  of  anethol  (p.  395). 

Vanillin — Methylprotocatechuic  Aldehyde  —  m-Methoxy-p-oxy- 
benzaldehyde  — C6H3.CHO.(O.CH3)(3)(OH)(4)— a  methylated  dioxy- 
benzaldehyde,  is  the  odoriferous  principle  of  vanilla.  It  is  produced 
artificially  by  oxidation  of  coniferin,  CieH^Os,  a  glucosid  occurring  in 
coniferous  plants  (p.  411).  It  crystallizes  in  needles,  fuses  at  80° 
(176°  F.),  is  sparingly  soluble  in  water,  readily  soluble  in  alcohol 
or  ether.  It  has  a  pungent  taste  and  a  persistent  odor  of  vanilla. 
On  exposure  to  air  it  becomes  partly  oxidized  to  vanillic  acid, 
C8H804. 

Cinnamic  Aldehyde  — £  Phenyl-acrolein  —  C6H5.CH:CH.CHO— 
is  an  example  of  the  aromatic  aldehydes  with  unsaturated  lateral 


400  MANUAL    OF    CHEMISTRY 

chains.  It  is  the  chief  constituent  of  oil  of  cinnamon;  and  is  a 
colorless,  aromatic  oil,  boiling  at  247°  (470.6°  F.).  It  oxidizes 
readily  to  cinnamic  acid  (p.  402). 


KETONES. 

The  aromatic  ketones  (p.  261)  are  produced  by  the  oxidation  of 
the  secondary  aromatic  alcohols  (p.  398)  ;  2C6H5.CHOH.CH3  -J-O2= 
2H2O+2C6H5.CO.CH3;  or  by  the  action  of  caustic  potash  upon  the 
aromatic  ft  ketone-carboxylic  acids  (p.  408):  C6H5.CO.CH2.COOH  + 
2KHO  =  C6H5.CO.CH3  +  H20  +  K2CO3.  Monoketones,  diketones 
and  triketones,  containing  one,  two  and  three  lateral  chains  with 
CO  groups,  are  known.  The  monoketones,  also  called  phenones, 
consist  of  a  closed  chain  hydrocarbon  group  united  to  an  open  chain 
one  by  the  group  (CO)".  They  may  also  be  considered  as  benzene, 
into  which  fatty  acid  radicals  have  been  substituted  for  hydrogen 
(see  p.  448). 

Phenyl-methyl  Ketone — Acetyl  benzene — Acetophenone — Hyp- 
none — CeHs.CO.CHs — is  obtained  by  distilling  a  mixture  of  calcium 
benzoate  and  acetate;  by  the  action  of  zinc -methyl  upon  benzoyl 
chlorid;  or  by  the  action  of  acetyl  chlorid  or  bromid  upon  benzene 
in  the  presence  of  aluminium  chlorid.  It  forms  large  crystalline 
plates,  fusible  at  20°  (68°  F.).  It  has  been  used  as  a  hypnotic. 

Acetophenone  Oxim  —  CeHs.C:  (N.OHj.CHs  —  is  isomeric  with 
acetanilid,  CeHs.NHXCO.CHs),  and  is  converted  into  that  substance 
by  the  action  of  concentrated  H2SO4  (p.  421). 


AROMATIC    CARBOXYLIC    ACIDS. 

All  six  of  the  hydrogen  atoms  of  benzene  are  replaceable  by 
carboxyl  groups,  with  formation  of  monocarboxylic  acids,  dicarboxylic 
acids,  etc.  There  are  also  three  series,  o-,  m-,  and  p-,  of  the  bi-, 
tri-,  and  tetracarboxylic  acids,  and  of  the  monocarboxylic  acids 
above  the  first.  These  acids  may  be  obtained  by  oxidation  of  the 
corresponding  alcohols,  or  aldehydes,  where  these  are  known.  Like 
the  aliphatic  acids,  they  may  be  considered  as  being  derived  from 
the  hydrocarbons  by  substitution  of  hydroxyl  for  hydrogen  in  a 
lateral  chain  (p.  238). 


MONOCARBOXYLIC    AROMATIC    ACIDS  —  BENZO1C    SERIES. 

These  acids  are  formed  by  many  methods,  among  which  the  most 
important  are:    (1)  By  oxidation  of  the  lateral  chain  in  hydrocarbons 


AROMATIC    CARBOXYLIC    ACIDS  401 

homologous  with  benzene.  Thus  toluene  yields  benzoic  acid:  2CeH5.- 
CH3+3O2=  2C6H5.COOH+2H2O;  (2)  by  oxidation  of  the  correspond- 
ing alcohols  and  aldehydes;  (3)  by  the  action  of  sodium  and  carbon 
dioxid  upon  the  monobromobenzenes:  CeHsBr-f  CO2-f2Na  =NaBr+ 
CeHs.COONa  ;  (4)  by  decomposition  of  the  aromatic  acid  nitrils  by 
acids  or  alkalies  (pp.  278,373) :  C6H5.CN+KHO+H20=C6H5.COOK+ 
NHs.  (5)  By  fusion  of  the  aromatic  sulfonic  acids  with  sodium  form- 
ate: CeHs.SOaNa-t-  H.COONa  =  C6H5.COONa+  NaHSO3. 

The  acids  of  this  series  form  many  derivatives.  In  some  of  these 
the  carboxyl  is  modified,  leaving  either  the  radical  benzoyl,  CeHs.CO, 
as  in  benzamid,  CeH5.CO.NH2,  or  the  trivalent  group  benzenyl, 
CeHs.C,  as  in  benzenyl-amidin,  CeH5.C^NH2.  In  others  the  substi- 
tution occurs  in  the  benzene  ring,  as  in  the  oxy-,  halogen-,  and 
nitro-benzoic  acids,  etc.,  e.g.  anthranilic,  or  o-amido-benzoic  acid, 
C6H4.COOH(1)(NH2)(2). 

Benzoic  Acid  —  CeHs.COOH — exists  in  benzoin,  tolu  balsam,  cas- 
toreum,  and  in  several  resins.  It  is  obtained  by  the  general  methods 
given  above;  also  from  benzoin,  and  from  the  urine  of  herbivorous 
animals.  The  urine  contains  hippuric  acid  (p.  425),  which,  on  de- 
composition, yields  benzoic  acid.  Conversely,  when  benzoic  acid  is 
taken  into  the  body  in  moderate  doses  it  is  eliminated  as  hippuric  acid. 

Benzoic  acid  crystallizes  in  white,  transparent  plates,  odorless, 
sparingly  soluble  in  cold  water,  readily  soluble  in  hot  water,  in  alcohol 
and  in  ether;  fuses  at  120°  (248°  F.),  boils  at  250° (482°  F.),  and  sub- 
limes at  temperatures  below  its  boiling  point.  Benzoic  acid  is  not 
attacked  by  HNOa.  Heated  with  lime,  it  yields  benzene  and  cal- 
cium carbonate:  CeHs.COOH +  CaH2O2  =  CeH6-i-CaC03  +  H2O.  The 
benzoates  are  all  soluble,  the  least  soluble  being  the  ferric  salt. 

Homologues  of  Benzoic  Acid. — These  are  of  two  kinds  :  (1) 
Those  in  which  the  carboxyl  and  hydrocarbon  groups  replace  different 
hydrogen  atoms,  the  alkyl-benzoic  acids,  as  cumic  acid,  or  p-isopro- 
pyl  benzoic  acid,  CeHsXCsHy^CCOOHJu).  (2)  Those  in  which  the 
carboxyl  is  separated  from  the  benzene  ring  by  a  hydrocarbon  group, 
the  phenyl  fatty  acids,  as  phenyl-acetic  acid,  CeH5.CH2.COOH.  In 
the  terras  above  the  first  of  this  series  there  are  place  isomeres  accord- 
ing to  the  distance  from  the  ring  in  which  the  carboxyl  is  introduced. 
Thus  «  phenyl-propionic  acid,  CeH5.CH<^CH3  ,  and  ft  phenyl-pro- 
pionic  acid,  C6H5.CH2.CH2.COOH. 


POLYCARBOXYLIC    AROMATIC    ACIDS. 

The  di-,  tri-,  tetra-,  penta-,  and  hexa-carboxylic  aromatic  acids 
are  derived  from  benzene  by  substitution  of  from  two  to  six  car- 

26 


402  MANUAL    OF    CHEMISTRY 

boxyls  for  hydrogen  atoms.  Of  the  superior  homologues  there  exist 
a  number  of  isomeres,  increasing  with  the  number  of  carbon  atoms, 
according  as  the  carboxyls  are  attached  to  the  benzene  ring,  as  in  the 
phthalic  acids,  or  are  contained  in  lateral  chains,  as  in  phenyl- 
malonic  acid,  CeHg.CHXCOOHh,  and  varying  further  by  differences 
in  orientation  either  in  the  benzene  or  the  lateral  chains. 

Phthalic  Acids  — C6H4(COOH)2  — Ortho-,  meta-,  and  para- 
phthalic  acids  are  produced  by  oxidation  of  the  corresponding 
bisubstituted  benzene  derivatives,  and  serve  by  their  formation  to 
determine  whether  a  given  compound  is  o-,  m-,  or  p-. 

Phthalic  Acid — Benzene-o-dicarboxylic  acid — CeEUtCOOHhd.a) 
— is  obtained  :  (1)  industrially  by  oxidation  of  naphthalene  or  tetra- 
chloronaphthalene,  for  use  in  the  manufacture  of  the  phthalein  dyes; 
(2)  by  oxidation  of  o-xylene,  o-toluic  acid,  etc.;  (3)  by  direct  union 
of  carbon  monoxid  with  salicylic  acid  :  C6H4.OH.COOH+CO=C6H4- 
(COOH)2;  or  with  resorcinol:  Ce^OHhH^CO^Cel^COOHh. 

Phthalic  acid  crystallizes  in  prisms,  sparingly  soluble  in  cold 
water,  readily  soluble  in  hot  water,  alcohol,  and  ether,  fuses  at  213° 
(415. 4°  F.).  Heated  with  CaH2C>2,  it  is  decomposed  into  benzene 
and  CO2.  Nascent  hydrogen  converts  it  into  hyrophthalic  acids 
(p.  437).  It  is  the  only  phthalic  acid  which  yields  an  anhydrid. 

Isophthalic  Acid — Benzene-m-dicarboxylic  acid — C6H4(COOH)2- 
(1.3) — is  formed  by  oxidation  of  m-xylene,  m-toluic  acid,  and  other 
m-benzene  bisubstituted  derivatives.  It  crystallizes  in  fine  needles, 
sparingly  soluble  in  water,  soluble  in  alcohol,  fuses  and  sublimes 
above  300°  (572°F.). 

Terephthalic  Acid — Benzene-p-dicarboxylic  acid — CelMCOOHh- 
(1,4) — is  formed  by  oxidation  of  p-xylene,  p-toluic  acid,  and  other 
p-benzene  bisubstituted  derivatives.  It  is  insoluble  in  water,  alcohol, 
and  ether,  and  sublimes  without  melting. 

UNSATUEATED    AROMATIC    CARBOXYLIC    ACIDS. 

Phenyl-olefin  carboxylic  Acids — In  some  of  these  acids  the  car- 
boxyl  is  attached  to  the  benzene  ring,  as  in  o-vinyl-benzoic  acid, 
COOH.C6H4.(CH:CH2)(2).  In  those  best  known  the  carboxyl  is  in 
the  lateral  chain.  They  are  obtained  by  oxidation  of  the  correspond- 
ing alcohols  or  aldehydes  (pp.  398,  399). 

Phenyl-acrylic  Acids — Two  are  known  :  Atropic  acid,  «  Phenyl- 

/COOH 

acrylic  acid,  C6H5.C^CH2  ,  a  product  of  decomposition  of  tropic 
acid  (p.  408) ;  and  cinnamic  acid,  ft  phenyl-acrylic  acid,  CeHs.CH:- 
CH.COOH,  which  exists  in  several  balsams  and  resins,  and  is  pro- 
duced in  the  decomposition  of  certain  alkaloids.  It  is  also  formed 
from  benzoic  aldehyde  by  the  action  of  acetyl  chlorid:  CH3.CO.C1+ 


PHENOL    CARBOXYLIC    ACIDS    AND    THEIR    ESTERS  403 

C6H5.CHO  =  C6H5.CH:CH.COOH-|-HC1;  or,  with  the  intermediate 
formation  of  phenyl-p-oxypropionic  acid,  by  the  action  of  sodium 
acetate  in  presence  of  acetic  anhydrid:  C6H5.CHO-f  CH3.COONa  = 
C6H5.CHOH.CH2.COONa,  and  C6H5.CHOH.CH2.COONa=C6H5.CH:- 
CH.COONa+H20.  It  crystallizes  in  prisms,  fuses  at  133°  (271.4°  F.), 
sparingly  soluble  in  cold  water,  readily  soluble  in  hot  water.  Oxidizing 
agents  convert  it  into  benzoic  aldehyde  and  benzoic  acid.  It  com- 
bines with  hydrogen  to  form  hydrocinnamic,  or  ft  phenyl-propionic 
acid,  C6H5.CH2.CH2.COOH.  Nitric  acid  converts  it  into  a  mixture 
of  o-  and  p-nitro-cinnamic  acids,  the  former  of  which  is  the  starting 
point  in  a  synthesis  of  indigo. 

On  heating  with  H2O  or  HC1,  atropic  acid  is  converted  into  two 
polymeric  isatropic  acids,  or  diatropic  acids,  (CgHg02)2. 

Piperic  Acid,  obtained  by  decomposition  of  piperin  by  heating 
with  alcoholic  KHO,  is  3-4-Methylene-dioxy-cinnamenyl-acrylic  acid: 

,/CH.CH^ 

w  r//°~C\  C.CH:CH.CH:CH.COOH. 

±12O  \  / 

\0 C  =  CH/ 

Phenyl-propiolic  acid=C6H5.C  I  C.COOH — is  a  phenyl-acetylene 
carboxylic  acid,  produced  by  the  action  of  carbon  dioxid  upon  phenyl- 
acetylene  :  C6H5.C;CH+CO2=C6H5.C;  C.COOH.  Its  o-nitro  de- 
rivative forms  isatin  (p.  466)  when  boiled  with  alkalies. 


PHENOL  CARBOXYLIC  ACIDS  AND  THEIR   ESTERS. 

These  compounds  have  both  hydroxyl  and  carboxyl  attached  to 
the  benzene  ring.  They  have  the  functions  of  phenol  and  of  acid. 
They  are  formed:  (1)  by  fusing  the  sulfobenzoic  acids  with  alkalies: 
C6H4(COOH)SO3H4-KHO=SO3HK-fC6H4(COOH)(OH),  (p.  389). 
Also  similarly  from  the  haloid  acids:  C6H4.Br.COOH-f  KHO=C6H4.- 
OH.COOH+KBr  ;  (2)  by  fusion  of  the  homologues  of  phenol  with 
caustic  potash,the  methyl  of  the  hydrocarbon  lateral  chain  is  oxidized 
to  carboxyl;  (3)  by  oxidation  of  the  phenol -aldehydes  by  fusion  with 
caustic  alkalies;  (4)  by  saponification  of  their  esters,  produced  by 
oxidizing  the  sulfuric  or  phosphoric  esters  of  the  homologues  of  phe- 
nol; (5)  by  heating  the  phenols  with  carbon  tetrachlorid  and  caustic 
potash  :  C6H5.OH+CCl4+4KHO==C6H4.OH.COOH  +  2H20-h4KCl; 
(6)  by  the  action  of  carbon  dioxid  upon  the  sodium  phenates:  2CeH5.- 
O.Na+C02=C6H4.0.Na.COONa+C6H5.OH. 

Di-,  tri-,  and  tetra- carboxylic  oxyacids  are  known.  But  the  best 
known  of  the  oxyacids  are  monocarboxylic,  and  monoxy-,  dioxy-,  and 
trioxy-,  corresponding  to  the  phenols  of  like  hydroxyl  content. 


404  MANUAL    OF    CHEMISTRY 

MONOXY-MONOCAEBOXYLIC    ACIDS. 

Oxybenzoic  Acids  — C6H4.OH.COOH.— Of  the  three  isomeric 
acids  the  meta-,  f.  p.  200°  (392°  F.),  and  the  para-,  f.  p.  210° 
(410°  F.),  acids  are  obtained  by  the  action  of  KHO  on  the  corre- 
sponding bromobenzoic  acids. 

Salicylic  Acid  —  o-Oxybenzoic  Acid  — f.  p.  155°  (311°  F.), 
occurs  free,  accompanied  by  salicylic  aldehyde  (p.  399),  in  Spiraea 
ulmaria  and,  as  its  methylic  ester,  in  oil  of  wintergreen.  It  is  also 
formed  by  decomposition  of  salicin,  coumarin  or  indigo.  It  is  pro- 
duced synthetically  by  the  above  reactions  and,  industrially,  by 
heating  sodium  phenate  in  a  current  of  carbon  dioxid.  The  reaction 
is  not  C6H5.ONa  +  CO2  =  C6H4.OH.COONa,  but  2C6H5.ONa+  CO2= 
C6H5.OH  +  C6H4.0Na.COONa. 

Salicylic  acid  crystallizes  in  prisms  or  needles,  sparingly  soluble 
in  cold  water,  readily  soluble  in  hot  water,  alcohol  and  ether,  sweet 
and  acid  in  taste.  When  heated,  it  distils  in  part  unchanged,  while 
a  part  loses  oxygen  and  yields  salol  and  xanthone,  CisHioC^;  or  salol, 
carbon  dioxid  and  water  (see  below).  With  Cl  and  Br  it  forms  pro- 
ducts of  substitution.  With  fuming  HNOs  it  forms  a  nitro-acid  and, 
finally,  picric  acid.  With  ferric  chlorid  it  gives  a  fine  violet  color. 
Nascent  hydrogen  causes  rupture  of  the  ring,  with  formation  of 
pimelic  acid  (p.  289)  as  a  final  product.  Salicylic  acid  and  its  salts 
and  esters  are  used  as  antiseptics  and  as  antirheumatics. 

Phenyl  Salicylate  —  Salol  —  C6H4.OH.COO(C6H5)  —  is  formed  by 
heating  salicylic  acid  to  220°  (428°  F.):  2C6H4.OH.COOH  =  C6H4.- 
OH.COO(C6H5)+CO2+H2O;  also  by  the  action  of  POC13  on  a 
mixture  of  salicylic  acid  and  phenol.  It  is  a  white,  crystalline  pow- 
der, faintly  aromatic  in  taste  and  odor,  almost  insoluble  in  water, 
soluble  in  alcohol,  ether  and  benzene,  fuses  at  43°  (110°  F.).  It  is 
not  decomposed  by  weak  acids,  but  is  saponified  by  alkalies  to  form 
salicylic  acid  and  phenol;  hence  it  passes  unchanged  through  the 
stomach  to  be  decomposed  in  the  intestine:  CeH4.  OH.  COO  ( CcH^)  + 
H2O  =  CeHi.OH.COOH  +  C6H5.OH. 

Acetol  Salicylate—  Salacetol—C6H4.OH.COO(CH2.CO.CH3)- 
the  ester  of  the  keto- alcohol,  acetol  (p.  263),  is  formed  by  the  action 
of  monochloracetone  on  sodium  salicylate.  It  crystallizes  in  plates, 
sparingly  soluble  in  water,  readily  soluble  in  alcohol,  fusible  at  71° 
(159.8°  F.).  It  is  saponified  by  alkalies  with  formation  of  acetol 
and  salicylic  acid,  and  is  hence  substituted  for  salol  as  a  medicine 
when  the  formation  of  phenol  is  undesirable.  Like  acetol  and  its 
other  esters,  it  reduces  Fehling's  solution. 

The  superior  homologues  of  the  salicylic  acids  are  either  alkyl  sub- 
stituted derivatives  of  the  oxybenzoic  acids  or  oxyphenyl  fatty  acids: 


PHENOL    CARBOXYLIC    ACIDS    AND    THEIE    ESTEttS  405 

COOH  COOH  CH2.COOH 

OH  r          "SOH 


o-Salicylic 
acid. 


CH3 

Orthoxyparatoluic 
acid. 


OH 

Paraoxyphenyl  acetic 
acid. 


Paraoxyphenylacetic  acid  and  paraoxyphenylpropionic  acid, 
C6H4(OH)(1)  (CH2.CH2.COOH)(4),  the  latter  also  called  hydroparacou- 
maric  acid,  exist  in  the  urine  in  "alkaptonuria,"  accompanied  by 
paraoxyphenylglycollic  acid,  C6H4(OH)(I)(CHOH.COOH)(4),  and  the 
dioxycarboxylic  acids  mentioned  below.  They  are  products  of  de- 
composition of  protein  material. 


DI-   AND   TRIOXYMONOCABBOXYLIC    ACIDS. 

Dioxycarboxylic  Acids. —  The  six  isomeres  corresponding  to  the 
three  diphenols  are  known,  as  well  as  numerous  alkyl  derivatives, 
such  as  vanillic,  isovanillic  and  veratric  acids,  which  are  derived  from 
protocatechuic  acid.  The  relations  of  these  acids  are  shown  by  the 
following  formulae: 


PYROCATECHOL. 
OH 


a  =  3.4-Dioxybenzoic. 

=  Protocatechuic. 
/3  =  2.3-Dioxybenzoic, 


OH 


X  No(CH3; 

COOH 

Vanillic  acid. 


RESORCINOL. 
OH 


a-Resorcylic, 
=  3.&-Dioxybenzoic, 
ft  -  Resorcylic, 
=  2.4-Dioxybenzoic. 
7  Resorcylic, 
—  2.6-Dioxybenzoic. 


COOH 

Isovanillic  acid. 


OH 

2.5-Dioxybenzoic, 
=  Gentisinic, 
==Hydroquinone-  car- 
boxy  lie. 


0(CH3) 


0 


COOH 
Veratric  acid. 


0(CH3) 


406  MANUAL    OF    CHEMISTRY 


Protocatechuic  Acid  —  3.4-Dioxybenzoic 
(OH)a(3.4)  —  exists  in  the  fruit  of  the  star-anise,  and  is  produced  from 
many  resins  by  fusion  with  KHO.  It  is  formed  by  fusion  of  the 
corresponding  dibromobenzoic  acid,  and  other  similar  derivatives, 
with  KHO. 

The  superior  homologues  of  dioxycarboxylic  acids  are  either 
dioxytoluic  acids,  etc.,  such  as  orsellinic  acid,  or  dioxy-phenyl  fatty 
acids,  such  as  homogentisinic  acid: 

CH2.COOH  CH2.COOH  CHo.CHOH.COOH 

OH 

<v  JOH          I  JOH 

CH3  OH  OH 

2.6-Dioxyparatoluic.    2.5-Dioxyphenyl-acetic.    3.4-Bioxyphenyl-acetic.      3.4-Dioxyphenyl-laetic. 
==•  Orsellinic.  =•  Homosentisinic.  =  Homoprotocatechuic.     =  Uroleucic  (?) 

Homogentisinic  acid,  or  glycosuric  acid,  exists  in  the  urine  in 
"alkaptonuria,"  probably  accompanied  by  homoprotocatechuic  and 
uroleucic  acids,  as  well  as  by  the  monoxy-monocarboxylic  acids 
mentioned  above. 

Trioxycarboxylic  Acids.  —  Three  of  the  six  possible  acids  are 
known,  two  derived  from  pyrogallol,  one  from  phloroglucin  (p.  394). 

Gallic  Acid  —  C6H2  (  COOH  )(1)(  OH)  3(3,4,5)—  exists  in  nature  in  cer- 
tain leaves,  seeds  and  fruits.  It  is  best  obtained  from  nut-galls,  which 
contain  its  glucosid,  gallo-tannic  acid.  It  is  formed  when  bromo- 
protocatechuic  acid  is  fused  with  caustic  potash.  It  crystallizes  in 
long,  silky  needles  with  lAq,  odorless,  acidulous  in  taste,  sparingly 
soluble  in  cold  water,  very  soluble  in  hot  water  and  in  alcohol.  Its 
solutions  are  acid.  When  heated  to  210-215°  (410-419°  F.)  it 
yields  C02  and  pyrogallol  (p.  395).  Its  solutions  reduce  the  salts 
of  silver  and  of  gold;  they  do  not  precipitate  gelatin  nor  the  salts 
of  the  alkaloids,  as  does  tannin;  and  they  give  a  blue  -black  precipitate 
with  Fe2Cl6. 

Tannins  —  Tannic  Acids  —  are  substances  of  vegetable  origin, 
principally  derived  from  leaves,  barks  and  seeds.  They  are  amor- 
phous, soluble  in  water,  astringent,  capable  of  precipitating  albumin, 
of  forming  imputrescible  compounds  with  the  gelatinoids  (leather), 
and  give  green  or  blue  colors  with  the  ferric  salts. 

Pure  tannic  acid  has  been  obtained  by  removal  of  water  from 
gallic  acid:  2C7H6O5=Ci4HioO9+H20;  it  is,  therefore,  digallic  acid. 
It  exists  in  gall-nuts,  excrescences  produced  upon  oak  trees  by  the 
punctures  of  certain  insects  (gallo-tannic  acid).  It  is  colorless, 
amorphous,  odorless,  very  soluble  in  water,  less  so  in  alcohol,  almost 


AROMATIC    ACIDS    AND    THEIR    ESTEKS  407 

insoluble  in  ether.     It  forms  a  dark -blue  liquid  (ink)  with  solutions 
of  ferric  salts  or,  after  exposure  to  air,  with  ferrous  salts. 

Caffetannic  Acid,  CaoHigOie,  exists  in  saline  combination  in  coffee 
and  Paraguay  tea.  It  colors  the  ferric  salts  green,  precipitates  the 
salts  of  quinin  and  cinchonin,  but  not  tartar  emetic  or  gelatin,  as 
tannic  acid  does.  It  yields  caffeic  acid,  or  3-4-dioxycinnamic  acid, 
CgHsC^,  on  decomposition.  Cachoutannic  acid,  obtained  from  ca- 
techu, is  soluble  in  water,  alcohol  and  ether.  It  precipitates  gelatin, 
but  not  tartar  emetic,  and  colors  ferric  salts  grayish -green.  Morin- 
tannic  acid,  or  maclurin,  CigHioOe,  is  a  yellow,  crystalline  substance, 
obtained  from  fustic.  It  is  more  soluble  in  alcohol  than  in  water. 
Its  solutions  precipitate  greenish -black  with  ferric  salts,  yellow 
with  lead  acetate,  brown  with  tartar  emetic  and  yellowish-brown 
with  cupric  sulfate.  Quercitannic  acid,  CigHieOio,  is  the  tannin  of 
oak  bark.  It  is  a  red  powder,  sparingly  soluble  in  water,  which 
forms  a  violet-red  precipitate  with  ferric  salts.  Quinotannic  acid 
exists  in  cinchona  barks,  in  combination  with  the  alkaloids.  It  is 
light  yellow,  soluble  in  water,  alcohol  and  ether,  astringent,  but  not 
bitter  in  taste.  It  is  colored  green  by  ferric  salts.  Dilute  EfeSCU 
decomposes  it  with  formation  of  quina  red,  an  amorphous  substance, 
which  yields  protocatechuic  and  acetic  acids  on  further  decompo- 
sition. 

ALCOHOL-,    ALDEHYDE-,    AND    KETONE-CARBOXYLIC   AROMATIC 
ACIDS;    AND    THEIR    ESTERS. 

The  aromatic  alcohol-acids  are  of  two  classes  :  (1)  alcohol-car- 
boxylic  acids,  in  which  the  group  CEbOH  is  attached  to  the  benzene 
ring,  and  (2)  phenyl-paraffin  alcohol-acids,  which  contain  either 
CH2OH;  CHOH  or  (CHO)//X  in  a  lateral  chain. 

The  three  oxymethyl-benzoic  acids  are  the  best  known  of  these 
acids,  and  of  these  the  o-acid,  CeH^COOH^CI^OH)^),  a  white 
powder,  fusible,  with  decomposition,  at  118°  (244. 4°  F.),  produced  by 
the  action  of  boiling  alkalies  upon 

Phthalid  —  C6H4\cH^/°^-its  lactone  (p.  320),  which  is  formed 
by  several  reactions,  as  by  the  reduction  of  phthalic  anhydrid  by 
nascent  hydrogen.  Phthalid  crystallizes  in  needles,  fusible  at  73° 
(163.4°  F.),  sparingly  soluble  in  cold  water,  rather  soluble  in  hot 
water.  Reducing  agents  convert  it  into  orthotoluic  acid;  oxidizing 
agents  into  phthalic  acid.  It  forms  a  number  of  substituted  ph thai- 
ids,  among  which  is  meconin  (see  also  p.  449). 

Meconin  —  5-6-Dimethyloxyphthalid  —  (CHsOh^A^^H^/0 
— the  lactone  of  meconinic  acid,  and  the  earliest  known  lactone, 


408  MANUAL    OF    CHEMISTRY 

exists  in  opium,  and  is  also  formed  by  the  action  of  reducing 
agents  upon  narcotin.  It  is  also  formed  by  reduction  of  the  corre- 

/f  OOTT 

spending  aldehyde- acid,  opianic  acid,  (CH3O)2CeH2<^CHQ  ,  a  product 

of  decomposition  of  narcotin  and  of  hydrastin.  Meconin,  or  opianyl, 
is  a  neutral,  non-poisonous,  crystalline  substance,  which  gives  a  fine 
green  color,  changing  to  red  after  24  hours,  with  H2SO4. 

The  phenyl-paraffin  alcohol-acids  may  be  considered  as  derived 
from  the  aliphatic  oxyacids  (p.  289)  by  substitution  of  phenyl,  CeHs, 
or  phenylene,  CeHi,  for  hydrogen  in  the  alcohol  or  hydrocarbon 
groups.  They  are  mono-  or  di-carboxylic  and  mono-  or  dioxy-,  and, 
in  the  higher  terms,  «,  /?,  etc. 

Phenylglycollic  Acid— Mandelic  Acid— C6H5.C*HOH.COOH— is 
the  lowest  term  of  the  series,  and  exists  in  three  optical  isomeres. 
The  inactive  acid  is  formed  by  the  action  of  nascent  hydrogen  upon 
benzoic  aldehyde,  CeH5.CHO,  or  upon  benzoyl -formic  acid,  CeHs- 
CO.COOH.  Oxidizing  agents  convert  it  first  into  beuzoyl- formic 
acid  and  then  into  benzoic  acid. 

Phenyllactic  Acids— «  and  /Sphenyllactic  acids,  C6H5.COH<^cooH' 
and  C6H5.CH2.CHOH.COOH,  and  «  and  ft  phenylhydracylic  acids, 
C6H5.C*H<^™oH'  and  C6H5.C*H\o|2-COOH,  are  known  (p.  292). 
Alpha-phenylhydracrylic  acid  is  tropic  acid,  the  inactive  modifica- 
tion of  which  is  a  product  of  decomposition  of  atropin  and  hyo- 
scyamin.  It  is  also  formed  synthetically  from  atropic  acid  (p.  402). 

The  dioxy-alcohol  acids  are  derived  from  the  acids  of  the  glyceric 
series  (p.  293),  as  a phenylglyceric  acid,  CH2OH.C(C6H5)OH.COOH. 

The  dicarboxylic  alcohol-acids  are  either  benzyl-  or  phenyl-alco- 
hol  acids  such  as  benzyl-tartronic  acid,(C6H5.CH2).COH:  (COOH)2; 
or  phenylene  oxydicarboxylic  acids,  such  as  carbomandelic  acid, 

/  C*C\f\TJ 

CeH4  \CHOH.COOH-    ^ne  phenylene  acids  readily  form  phthalid  acids 

(lactones)  more  stable  than  themselves,  such  as  phthalid-acetic  acid, 
/CO— O 

CH.COOH. 

The  aromatic  aldehyde  acids  contain  the  carboxyl  and  aldehyde 
groups  attached  to  the  benzene  ring,  as  in  opianic  acid  (above). 

In  the  ketone  acids  the  ketone  group  (CO)"  is  necessarily  in  a 
lateral  chain.  In  some  of  these  acids  the  ketone  and  carboxyl  groups 

are  in  different  lateral  chains,  as  in  aceto-benzoic  acid,  CeH^QQ  CH3, 

but  in  most  of  them  the  two  groups  are  in  the  same  chain,  and  are 
a,  ft,  y,  etc.,  according  to  the  removal  of  the  CO  from  the  COOH 
group.  Thus  benzoyl  -  formic  acid,  CeH5.CO.COOH,  is  «,  and 
benzoyl  acetic  acid,  C6H5.CO.CH2.COOH,  is  ft. 


PHENYLIC    ETHERS  —  GLUCOSIDS  409 

Besides  the  above  there  are  also  known:  Phenyl-alcohol-ketone 
acids,  such  as  benzoyl-glycollic  acid,C6H5.CO.CHOH.COOH;  phenyl- 
diketone-acids,  such  as  benzoyl-pyroracemic  acid,  CeHs.CO.CH^.CO.- 
COOH;  phenyl-ketone-dicarboxylic  acids,  such  as  benzoyl-malonic 
acid,  C6H5.CO.CH:(COOH)2;  and  phenylene-ketone-dicarboxylic 

acids,  such  as  phthalonic  acid, 


PHENYLIC    ETHERS  — GLUCOSIDS. 

The  oxids  of  the  aromatic  series,  corresponding  to  the  aliphatic 
ethers  (p.  299),  and  containing  two  cyclic  hydrocarbon  groups  united 
by  an  oxygen  atom,  properly  belong  among  the  dibenzenic  compounds 
(p.  384),  but  are  more  conveniently  considered  here. 

Phenyl  Ether — Diphenyl  Oxid  —  ( Cells)  2<3 — is  formed  by  heating 
phenol  with  aluminium  chlorid,  or  with  zinc  chlorid:  2CoH.5.O1EL=  C&- 
H5.O.C6H5+H2O,  and  by  other  more  circuitous  methods.  It  crystal- 
lizes in  long  needles,  having  the  odor  of  geranium,  soluble  in  alcohol 
and  in  ether.  Corresponding  to  it  are  a  number  of  derivatives, 
formed  by  substitution  of  various  univalents  for  the  remaining  phe- 
nol hydrogen. 

The  mixed  oxids,  containing  a  phenyl  and  an  alkyl  group,  such 
as  anisol,  CeHs.O.CHs,  are  the  phenyl  ethers  (p.  391),  derived 
from  phenol  and  its  homologues. 


GLUCOSIDS. 

The  name  "  glucosid  "  was  first  applied  to  certain  natural  products, 
some  of  which  are  the  active  constituents  of  medicinal  plants,  which, 
on  decomposition  by  dilute  mineral  acids,  yield  glucose  and  some 
other  substance.  Subsequently,  it  was  found  that  the  sugars  derived 
from  some  of  these  substances  differ  from  glucose  ;  some  are  pen- 
toses,  others  hexoses;  some  monosaccharids,  others  disaccharids ; 
some  aldoses,  others  ketoses.  On  the  other  hand,  the  second  product 
of  decomposition  has  been  of  the  most  varied  character,  phenols, 
alphenols,  alcohols,  oxyphenols,  monobenzenic  or  dibenzenic,  but,  in 
all  those  natural  glucosids  which  have  been  investigated,  always  a 
cyclic  compound,  containing  a  phenolic  or  an  alcoholic  group.  The 
glucosids  have  usually  been  regarded  as  esters  of  glucose,  etc.,  since 
the  alcoholic  character  of  the  sugars  has  been  recognized,  but,  as 
the  union  of  the  sugar  and  benzenic  factors  is  through  an  oxygen 
atom,  and  not  by  replacement  of  the  hydrogen  of  a  carboxyl,  they 
are  more  properly  regarded  as  ethers  (p.  299),  formed  by  union  of 
an  aldose  or  ketose  remainder  with  one  of  a  phenolic  or  alcoholic 


410  MANUAL    OF    CHEMISTRY 

benzenic  compound,  with  elimination  of  H2O.  The  constitution  of 
the  glucosids  cannot,  however,  be  considered  as  established,  as  no 
natural  glucosid  has  been  obtained  synthetically,  although  the  prod- 
ucts of  decomposition  of  some  are  comparatively  simple  compounds. 
It  is  to  be  supposed  that  the  union  takes  place  through  the  aldehyde 
group,  as  the  glucosids  do  not  reduce  Fehling's  solution  and  do 
not  form  osazones.  They  probably  contain  some  such  grouping  as: 

X°\ 

CH2OH.(CHOH)3.CH-  -CH.O.B,  in  which  B  represents  the  ben- 
zenic factor. 

The  glucosids  are  decomposed  (hydrolized)  by  heating  with  dilute 
acids,  or,  at  very  slightly  elevated  temperatures,  by  certain  enzymes, 
such  as  emulsin,  which  exists  in  almonds,  myrosin,  in  mustard 
seeds,  the  invertin  of  malt,  and  salivary  and  intestinal  enzymes.  They 
are  very  slowly  hydrolyzed  by  heating  with  water  under  pressure,  if 
at  all;  and  only  a  few  of  them  are  decomposed  by  alkalies. 

The  glucosids  yielding  pentoses  on  hydrolysis  are  more  properly 
designated  pentosids. 

Phenyl  Glucosid — Glucosyl  phenate  —  CeHiiOs.O.CeHs  —  is  the 
simplest  of  the  glucosids,  and  is  an  artificial  product,  formed  by  mix- 
ing alcoholic  solutions  of  acetochlorhydrose  (p.  320)  and  potassium 
phenate,  CHO.  (CH.CO2.CH3)4.CH2C1  +  C6H5.O.K-h4H2O  =  CHO.- 
(CHOH)4.CH2.0.C6H5+KCH-4CH3.COOH.  It  forms  soluble,  crys- 
talline needles,  fusible  at  172°,  and  is  decomposed  by  emulsin  into 
glucose  and  phenol. 

Among  the  more  important  of  the  natural  glucosids  are  the  fol- 
lowing : 

-<Esculin — CisHieOg — which  exists  in  the  rinds  of  horse-chestnuts. 
It  forms  colorless  crystals,  sparingly  soluble  in  water,  the  solutions 
having  a  brilliant  blue  fluorescence,  even  when  very  dilute.  It  forms 
a  yellow  solution  with  HNOs,  which  becomes  deep  blood -red  on  super- 
saturation  with  ammonia.  It  is  decomposed  by  dilute  mineral  acids, 
or  by  emulsin,  into  glucose  and  aesculetin,  CoHeO^  which  is  prob- 

xCH:CH 
ably  a  dioxy  -  derivative  of  coumarin  ( p .  463 ) :  CeH2  ( OH )  2<^        I    . 

Amygdalin — C2oH27NOn — exists  in  the  bitter  almond,  in  the  ker- 
nels of  peach-  and  plum -pits,  apple-  and  pear -seeds,  and  a  great 
variety  of  other  plants.  It  crystallizes  in  colorless  prisms  with  3Aq, 
easily  soluble  in  water,  insoluble  in  ether,  odorless,  and  bitter.  It  is 
decomposed  by  dilute  mineral  acids,  or  by  emulsin,  into  two  mole- 
cules of  glucose  and  one  each  of  benzoic  aldehyde  and  hydrocyanic 
acid:  C2oH27NOiiH-2H2O=2C6H7O(OH)5+CcH5.CHO+CNH.  By  the 
action  of  alkalies,  particularly  by  heating  with  BaH2O2,  amygdalin 
yields  amygdalic  acid,  C2oH28Oi3,  of  which  amygdalin  appears  to  be 


PHENYLIC    ETHERS  — GLUCOSIDS  411 

the  nitril:  C6H7O(OH)4.O.C6H70(OH)3.0.CH(C6H5)CN,  and  this,  on 
splitting  off  of  the  sugar,  first  forms  the  nitril  of  mandelic  acid 
(p.  408) :  CeHs.CHOH.CN,  the  subsequent  decomposition  of  which 
into  Cells. CHO  and  HCN  is  evident.  Amygdalin  itself  is  non- poi- 
sonous, but  its  ready  decomposition,  with  formation  of  the  extremely 
poisonous  hydrocyanic  acid,  is  a  prolific  source  of  cyanic  poisoning. 

Antiarin — CuH^Os — is  the  poisonous  constituent  of  the  juice  of 
Upas  antiar,  used  as  an  arrow -poison.  Apiin,  C27H32Oi6,  is  a  glu- 
cosid  obtained  from  parsley  and  other  umbelliferous  plants.  Arbutin, 
C^HieOy,  accompanied  by  methyl- arbutin,  occurs  in  Arbutus  uva-ursi, 
and  yields  hydroquinone  on  decomposition.  It  gives  a  blue  color 
with  ferric  chlorid.  Carminic  acid,  CnHigOio,  is  the  coloring  prin- 
ciple of  cochineal  and  of  carmine,  and  is  a  weak  dibasic  acid.  It  is  a 
dark -purple  substance,  decomposed  by  acids  into  an  inactive,  unfer- 
rnentable  sugar,  and  carmine-red,  CnH^O?. 

Coniferin — CieH^Og — is  a  glucosid  occurring  in  the  inner  bark 
(cambium)  of  coniferous  plants,  and  in  asparagus  and  the  sugar- 
beet.  It  crystallizes  in  silky,  white  needles,  sparingly  soluble  in 
water,  faintly  bitter.  With  phenol  and  concentrated  hydrochloric 
acid  it  assumes  an  intense  blue  color  (pine -shaving  reaction,  p.  390). 
It  is  decomposed  by  emulsin  into  glucose  and  coniferyl  alcohol, 
which  is  a  hydroxyl-oxymethyl  cinnamyl  alcohol  (p.  398)  :  CHs- 
^0/C6H3.CH:CH.CH2OH.  By  oxidation  with  chromic  acid  it  forms 
glucovanillin,  CeHi^.O.CeHstOCHsjCHO,  which  is  decomposed  by 
emulsin  into  glucose  and  vanillin:  methylprotocatechuic  aldehyde 
(p.  399).  Glucovanillin,  containing  an  aldehyde  group,  forms  a 
crystalline  compound  with  phenylhydrazin,  and  an  oxim.  By  further 
oxidation  it  forms  glucovanillic  acid,  and  by  reduction,  the  corre- 
sponding alcohol. 

Convolvulin — is  a  glucosid  of  undetermined  composition,  which 
is  the  active  constituent  of  jalap.  It  is  a  yellowish,  slightly  acid, 
amorphous  material,  sparingly  soluble  in  water,  easily  soluble  in 
alcohol,  forming  a  deep-red  solution  with  E^SCU.  Crocin,  C^HvoC^s, 
is  the  coloring  matter  of  saffron,  an  amorphous,  yellow  substance,  sol- 
uble in  water  and  in  alcohol.  With  concentrated  H2SO4,  it  gives  a  deep- 
blue  color,  changing  to  violet,  red,  and  brown.  It  is  decomposed  by 
dilute  hydrochloric  acid  into  a  dextrogyrous  hexose,  having  half  the 
reducing  power  of  glucose,  and  crocetin,  C34H46Og,  an  orange-yellow 
substance  soluble  in  alcohol  and  ether,  but  almost  insoluble  in  water. 
Cyclamin,  C2oH34On,  is  a  white,  crystalline  glucosid  existing  in 
various  species  of  Cyclamen.  Daphnin,  CisHieOg,  occurs  in  the  bark 
of  Daphne  mezereum,  and  other  species  of  Daphne.  It  crystallizes  in 
colorless  prisms,  bitter  and  astringent,  sparingly  soluble  in  water  and 
in  ether,  soluble  in  alcohol.  It  is  colored  bluish  by  ferric  chlorid. 


412  MANUAL    OP    CHEMISTRY 

It  is  decomposed  into  glucose  and  daphnetin,  CgHeC^,  isomeric  with 
aesculetin  (above)  .  Daphnetin  has  been  shown  to  be  a  dioxycoumarin, 
having  the  hydroxyls  in  the  positions  1,  2,  by  its  synthesis  by  conden- 
sation of  pyrogallol  (p.  394)  and  malic  acid:C6H3(OH)3ci,2,3)-fCOOH.- 

/0(3)—  CO 


Digitalis  Glucosids.  —  The  active  substance  of  digitalis  consists, 
in  part  at  least,  of  a  glucosid,  or  glucosids,  probably  accompanied  by 
products  of  decomposition,  but  the  chemistry  of  these  compounds 
requires  further  investigation.  Digitonin,  C2?H44Oi3(?),  is  the  most 
abundant  constituent  of  the  "amorphous  digitalins,"  and  has  little  or 
no  therapeutic  value.  It  is  an  amorphous,  white  solid,  very  sol- 
uble in  water,  which  crystallizes  from  its  alcoholic  solutions.  It  is 
decomposed  by  dilute  hydrochloric  acid  into  digitonein,  or  digito- 
genin,  CisH^C^,  glucose  and  galactose.  Digitalin,  (CsHsC^M?), 
separates  in  amorphous  or  nodular  masses  from  its  alcoholic  solution. 
On  decomposition  it  yields  digitaliresin,  Ci6H2202,  glucose  and  digi- 
talose,  CyHuOs.  It  has  the  physiological  action  of  digitalis  upon  the 
heart,  and  is  the  principal  constituent  of  "Homolle's  digitalin." 
Digitoxin,  C2iH32O7(f),  crystallizes  in  fine  needles,  insoluble  in  water, 
soluble  in  hot  alcohol  and  in  chloroform.  It  is  the  most  actively 
poisonous  .of  the  digitalis  glucosids,  and  is  the  chief  constituent  of 
"Nativelle's  digitalin."  Digitalin  gives  a  color-reaction  which  is  not 
given  by  digitoxin  :  it  forms  a  golden-yellow  or  brownish  solution 
with  concentrated  H2S04,  which  becomes  violet-red  by  the  action  of 
bromin-vapor. 

Frangulin  —  C2iH2oO9  —  is  a  pentosid,  existing  in  the  bark  of 
Rhamnus  frangula.  It  forms  yellow  crystals,  almost  insoluble  in 
water,  which,  on  decomposition,  yield  emodin  (p.  445),  and  the  pen- 
tose,  rhamnose,  CH3.(CHOH)4.CHO.  Fraxin,  Ci6Hi8Oio,  accompa- 
nies aesculin  in  the  horse-chestnut  and  occurs  in  ash-bark.  It  is  a 
white,  crystalline  solid,  sparingly  soluble  in  water,  its  solutions  show- 
ing a  blue  fluorescence.  It  is  decomposed  into  glucose,  and  fraxetin, 

/O  —  CO 

a  methyl  ether  of  trioxycoumarin,  CeBXOHMO.CHsK  (page 

CH  t  CH 

463).  Helleborein,  C26H44Oi5,  and  helleborin,  CseH^Oe,  are  two  poi- 
sonous, crystalline  glucosids  occurring  in  black  hellebore.  On  de- 
composition they  both  yield  glucose,  and  the  former  helleboretin, 
Ci4H2oO3(?),  and  the  latter  helleboresin,  CsoHasO*  (?). 

Hesperidin  —  C^H^eO^O)  —  occurs  in  unripe  oranges,  lemons, 
etc.  It  forms  crystalline  needles,  very  sparingly  soluble  in  most  sol- 
vents, except  hot  acetic  ether,  soluble  in  dilute  alkaline  solutions.  It 
is  one  of  the  few  glucosids  yielding  both  a  hexose  and  a  pentose  on 
decomposition;  being  split  by  heating  with  dilute  H2SO4  into  glu- 


PHENYLIC    ETHERS—  GLUCOSIDS  413 


cose,  rhamnose,  and  hesperetin,  CieHuOe.  Hesperetin  is  further  de- 
composed by  heating  with  caustic  potash  into  phloroglucin  (p.  394) 
and  hesperetic,  or  isoferulic  acid,  CeHsCCHrCH.COOHMOH),,)- 
(O.CHsJu),  a  derivative  of  cinnamic  acid  (p.  402).  It  therefore  con- 
tains two  benzene  nuclei. 

Indican  —  C26H3iNOn  —  is  a  glucosid  occurring  in  the  indigo  plant. 
It  is  a  yellow  or  light-brown  syrup,  which  cannot  be  dried  without 
decomposition,  bitter  and  disagreeable  in  taste,  acid  in  reaction,  and 
soluble  in  water,  alcohol  and  ether.  It  is  very  prone  to  decomposi- 
tion. Even  slight  heating  decomposes  it  into  leucin,  indicanin,  €20- 
H23NOi2,  and  indiglucin,  CeHioOe.  A  characteristic  decomposition  is 
that  by  which  it  yields  indigo  -blue  (p.  466)  and  indiglucin,  along 
with  other  products:  2C26H3iNOi7+4H2O  —  Ci6HioN2O2+6C6HioO6. 

Jalapin  —  Scammonin  —  C^HseOie  —  is  the  glucosid  of  scammony. 
It  is  an  insipid,  colorless,  amorphous  substance,  decomposable  into 
jalapinol,  CieHsoOs,  and  glucose.  Myronic  acid,  CioHi9NS20io,  exists 
as  its  potassium  salt  in  the  seeds  of  black  mustard.  Potassium 
myronate  crystallizes  in  prisms;  very  soluble  in  water,  almost  insol- 
uble in  alcohol,  which  are  decomposed  by  boiling  with  BaB^C^,  or 
by  myrosin,  an  enzym  which  accompanies  it  in  the  mustard  seeds, 
into  glucose,  allyl  isothiocyanate  (p.  377)  and  monpotassic  sulfate. 
Naringin,  C2iH260n,  is  a  pentosid,  occurring  in  the  blossoms  and 
fruit  of  a  Java  orange.  It  forms  yellow  crystals,  bitter  in  taste, 
sparingly  soluble  in  water,  decomposable  by  dilute  acids  into  rham- 
nose and  naringenin,  CisH^Os,  which  is  in  turn  decomposed  by 
alkalies  into  phloroglucin  and  naringenic  acid,  or  p-coumaric  acid, 
CgHgOs.  Phloridzin,  C2iH.24Oio,  occurs  in  the  root  -bark  of  apple 
and  other  fruit  trees.  It  crystallizes  in  flat,  colorless  needles,  bitter- 
sweet in  taste,  difficultly  soluble  in  cold  water,  but  readily  soluble  in 
hot  water  and  in  alcohol.  It  is  decomposed  by  heating  with  dilute 
acids,  or  even  by  prolonged  boiling  with  water,  into  a  crystalline, 
dextrogyrous  hexose,  phlorose,  and  phloretin,  CisHuOs,  which  is 
further  decomposed  by  hot  alkalies  into  phloroglucin  and  phloretic, 
or  p-oxyhydratropic  acid,  C6H4(OH).C2H4.COOH  (p.  403).  Querci- 
trin,  CaeHsgC^o,  is  the  coloring  principle  of  a  yellow  dye-stuff  called 
flavin,  obtained  from  Quercus  tinctoria.  It  crystallizes  in  yellow 
needles,  sparingly  soluble  in  water.  It  is  a  pentosid,  and  is  decom- 
posable by  acids  into  rhamnose  and  quercetin,  C24Hi6On,  a  benzopy- 
rone  derivative  (p.  464).  Quinovin,  or  quinovic  acid,  CssH^On  (?), 
is  a  bitter  substance,  occurring  in  false  cinchona  barks,  decomposable 
into  a  peculiar  pentose,  quinovose,  CeH^C^,  and  quinovic  acid, 


Salicin  —  CisHisO?  —  occurs  in  willow  bark.     It  is  a  white,  crys- 
talline substance,  insoluble  in  ether,  soluble  in  water  and  in  alcohol, 


414  MANUAL    OF    CHEMISTRY 

very  bitter  in  taste.  Concentrated  H2S04  colors  it  intensely  red,  the 
color  being  discharged  by  addition  of  water.  It  is  decomposed  by 
emulsin,  by  saliva,  or  by  mineral  acids  into  glucose  and  saligenin 
(p.  398).  When  taken  into  the  economy  it  is  converted  into  salicylic 
aldehyde  and  acid,  which  are  eliminated  in  the  urine.  Populin,  a 
glucosid  from  poplar  bark,  is  benzoyl-salicin. 

Solanin  —  C42H8?NOi5(?) — is  a  glucosid  having  basic  properties, 
an  alkaloid -glucosid,  occurring  in  a  variety  of  plants  of  the  genus 
Solanum.  It  crystallizes  in  white,  silky  needles,  acrid  and  bitter  in 
taste,  insoluble  in  water,  sparingly  soluble  in  alcohol  and  in  ether.  By 
the  action  of  hot  dilute  acids  it  is  decomposed  into  glucose  and  a 
basic  substance,  solanidin.  When  not  heated,  solanin  combines  with 
acids  to  form  uncrystallizable  salts.  Cold,  concentrated  H2SO4  colors 
it  orange -yellow,  and  finally  forms  with  it  a  brown  solution.  Nitric 
acid  dissolves  it,  the  solution  being  at  first  colorless,  afterwards 
rose -pink. 

ANHYDRIDS    AND    ACID    HALOIDS. 

The  aromatic  acidyls  form  oxids,  or  anhydrids,  and  haloid  com- 
pounds, corresponding  to  those  of  the  aliphatic  acidyls,  and  produced 
by  similar  methods  (pp.  310,  311). 

Benzoic  Anhydrid — (CeH^.COhO — is  formed  from  benzoyl  chlorid 
by  several  methods:  as  by  a  reaction  between  benzoyl  chlorid  and 
silver  benzoate:  CeHs.CO.Cl+CeHs.COOAg^CeHs.COhO+AgCl. 
It  is  a  crystalline  solid,  f .  p.  42°,  b.  p.  360°. 

Phthalic  Anhydrid — CeH^COh'O — being  formed  from  a  dicar- 
boxylic  acid,  is  produced  from  a  single  molecule  of  the  acid,  with 
elimination  of  EUO.  It  is  formed  by  fusing  phthalic  acid.  It  sub- 
limes in  needles;  f.  p.  128°  (262.4°  F.) ;  sparingly  soluble  in  cold 
water,  soluble  in  hot  water,  with  regeneration  of  the  acid,  very  sol- 
uble in  alcohol  and  in  ether.  It  combines  with  phenols  to  form 
phthaleins  (p.  396). 

Benzoyl  Chlorid — C6H5.CO.C1  —  was  the  first  obtained  of  the 
acidyl  haloids.  It  is  formed  by  the  action  of  hydrochloric  acid  upon 
benzoic  acid,  in  presence  of  phosphorus  pentoxid  :  CeHs.COOHH- 
HCl=C6H5.CO.Cl-fH2O;  or  by  the  action  of  chlorin  upon  benzoic 
aldehyde:  Ce^.CHO+C^HCl+CeHs.CO.Cl;  or,  along  with  acetyl 
chlorid,  by  the  action  of  chlorin  upon  benzyl  acetate  :  CHa.COO- 
(CH2.C6H5)+2C12=C6H5.CO.C1+CH3.CO.C1+2HC1.  The  two  chlor- 
ids  are  separated  by  fractional  distillation. 

Benzoyl  chlorid  is  a  colorless  liquid;  b.  p.  198°;  having  a  pene- 
trating odor.  With  silver  (or  mercuric)  cyanid  it  forms  benzoyl 
cyanid  :  C6H5.CO.Cl+AgCN=C6H5.CO.CN-f  AgCl.  It  acts  readily 
upon  the  polyatomic  alcohols  and  upon  the  hexoses,  when  shaken 


AROMATIC    SULFUR- DERIVATIVES -SULFONIC    ACIDS         415 

with  their  solutions  in  presence  of  caustic  soda.  With  the  hexoses 
peutabenzoyl  compounds  are  formed,  and  crystallize  out:  CHO.CsHe- 
(OH)5+5C6H5.CO.C1=CHO.C5H6(O.CO.C6H5)5+5HC1.  This  is  a 
reaction  utilized  for  the  isolation  of  hexoses  and  polyatomic  alcohols. 
A  similar  reaction,  similarly  utilized,  occurs  with  the  diamins,  in 
which  insoluble,  crystalline,  dibenzoyl  compounds  are  formed: 


AROMATIC  SULFUR-DERIVATIVES-SULFONIC    ACIDS. 

Many  thio-aromatic  compounds  are  known,  as  thiophenol, 
SH,  phenyl  sulfid,  (CeHshS,  and  thio-benzoic  acid,  C6H5.COSH. 
But  the  most  important  of  the  aromatic  compounds  containing  sul- 
fur are  the 

Sulfonic  Acids  (p.  322),  monobasic  acids  containing  the  group 
SOsH,  formed  by  the  union  of  the  aromatic  hydrocarbon,  or  deriva- 
tive, with  H2SO4  with  elimination  of  OH  from  the  acid  and  H  from 
the  aromatic  compound,  a  process  called  "  sulf onation" :  CeHe+H^- 
804=06115.80311+1120.  The  aromatic  and  polybenzenic  sulfonic 
acids  are  formed  much  more  readily  than  the  corresponding  aliphatic 
acids,  and,  being  acid  and  soluble,  are  largely  used  as  dyes.  They 
are  usually  produced  by  the  action  of  fuming  H28O4  upon  the  aro- 
matic compound,  with  or  without  the  aid  of  heat. 

The  sulfonic  acids  are  not  decomposed  by  boiling  with  alkaline  solu- 
tions, but  their  salts,  when  fused  with  caustic  alkalies,  yield  phenols: 
C6H5.SO3K+KHO  =  C6H5.OH+K2SO3.  Distilled  with  potassium 
cyanid  they  yield  nitrils:  C6H5.SO3K  +  KCN=C6H5.CN  +  K2SO3. 
By  the  action  of  PCls  they  are  converted  into  their  chlorids,  e.  g. 
Cells. S02C1,  which  may  be,  in  turn,  converted  into  sulfinic  acids, 
sulf  ones,  etc.  They  are  easily  soluble  in  water,  and  may  be  separated 
from  their  solutions,  as  sodium  salts,  by  the  addition  of  NaCl 

Benzene-monosulfonic  Acid — Cells. SOsH — is  formed  by  dissolv- 
ing benzene  in  weak  fuming  sulfuric  acid  at  a  slightly  elevated  tem- 
perature, and  diluting  with  EbO.  It  crystallizes  in  extremely  soluble, 
deliquescent  plates  with  1%  Aq. 

Three  benzene-disulfonic  acids  —  CeEUfSOsHh — ortho-,  meta-  and 
para-,  are  known,  also  one  benzene-trisulfonic  acid  —  CeHsfSOsEOs. 

Three  toluene-sulfonic  acids  —  Cel^CHsJ.SOsH  —  ortho-,  meta- 
and  para-,  have  been  obtained.  By  the  action  of  a  mixture  of  ordinary 
and  fuming  sulfuric  acids  upon  toluene  at  a  temperature  not  exceed- 
ing 100°  (212°  F.),  a  mixture  of  the  ortho-  and  para-  acids  is  pro- 
duced. When  this  is  treated  with  PCls,  it  is  converted  into  a  mixture 
of  para-  and  ortho  -  toluene  sulfonic  chlorids  —  C6H4.CH3.SO2C1. 
The  ortho -chlorid,  when  acted  on  by  dry  ammonia  and  ammonium 


416  MANUAL    OF    CHEMISTRY 

carbonate,  is  converted  into  ortho-toluene  sulfimid  — 
SO2NH2.  This  product,  when  oxidized  by  potassium  permanganate, 
is  converted  into  benzoyl-sulfonic  imid — CeH^CO.SC^NEb  —  or  sac- 
charin—  an  odorless,  crystalline  powder,  having  great  sweetening 
power,  its  sweet  taste  being  still  detectable  in  a  dilution  of  1-50,000. 
Sparingly  soluble  in  water  and  in  ether,  readily  in  alcohol.  Its 
solutions  are  acid  in  reaction.  When  heated  with  Na2CO3  it  is 
carbonized  and  gives  off  an  odor  of  benzene.  It  is  not  attacked  by 
H2SO4. 

Another  series  of  sulfonic  derivatives  is  obtained  from  the  phenols. 
Among  them  is: 

Ortho -phenol  sulfonic  Acid  —  Sozolic  acid  —  Aseptol — CeH^- 
(OH)(i)(S03H)(2) — which  is  prepared  by  the  action  of  cold  concentrated 
H2S04  upon  phenol.  It  is  a  reddish,  syrupy  liquid,  soluble  in  H2O 
in  all  proportions,  has  a  faint  and  not  disagreeable  odor.  It  prevents 
fermentation  and  putrefaction,  and  is  a  non- poisonous,  non- irritant 
antiseptic.  The  salts  of  this  and  the  corresponding  para-  and  rneta- 
acids  have  been  used  as  antiseptics  and  insecticides,  under  the  name 
of  sulfo-carbolates,  e.g.  Sodii  sulfo-carbolas  (U.  S.). 

Guaiacol-sulfonic  Acid  is  used  in  medicine  as  its  potassium  salt, 
C6H3(OH)(I)(OCH3)(2)SO3K,  under  the  name  thiocol. 

Salicyl  -  sulfonic  acid— C6H4.COOH.O.SO3H  — is  a  crystalline 
solid,  formed  by  the  action  of  strong  H2SO4  on  salicylic  acid.  It  is 
easily  soluble  in  H2O.  It  has  been  recommended  as  a  test  for 
albumin. 

Diiodo-phenol  monosulfonic  Acid  —  C6H2I2.OH.SO3H  — is  used 
as  an  antiseptic  and  astringent,  in  the  form  of  its  salts  under  the 
name  sozoiodol ;  and  Diiodo-resorcinol  monosulfonic  acid — G6HI2.- 
(OH)(i-3).SO3H  —  is  also  used  as  an  antiseptic  having  but  slight 
poisonous  qualities,  under  the  name  picrol. 


NITROGEN-CONTAINING    DERIVATIVES    OF    BENZENE. 

The  nitrogen  derivatives  of  benzene  are  very  numerous,  of  great 
variety  of  structure,  and  include  among  their  number  several  sub- 
stances of  great  industrial  value. 

They  may  be  classified  into  five  principal  groups:  (1)  The  nitro- 
compounds,  derived  from  other  benzenic  compounds  by  substitution 
pf  NO2  for  H,  and  the  nitroso-compounds,  containing  the  nitroso 
group,  NO;  (2)  The  ft  hydroxylamin  compounds,  containing  the 

group  — NX'JJ  ,  and  their  nitroso  derivatives;  (3)  the  amido-  and 
imido- compounds,  containing  NH2  and  NH,  the  aromatic  amins, 
amids,  and  amido-acids,  and  their  derivatives;  (4)  the  azo-  and 


NITROGEN  -  CONTAINING    DERIVATIVES    OP    BENZENE          417 

diazo-compounds  and  their  numerous  derivatives,  containing  the 
grouping  — N=N — ;  (5)  the  hydrazins,  containing  the  grouping 
==N — N==,  and  their  nitroso  derivatives. 


NITEO-    AND    NITROSO -COMPOUNDS 

Nitro-benzenes. —  These  contain  the  nitro  group  directly  attached 
to  the  carbon  of  the  benzene  ring.  They  are  produced  by  the  action 
of  fuming  HNOs,  or  a  mixture  of  HNO3  and  EfeSCk,  upon  the  hydro- 
carbons: C6H6+HN03=C6H5.N02+H2O.  They  are  yellow  liquids, 
sparingly  soluble  in  water.  Their  most  important  property  is  their 
ready  reduction,  first  to  /? hydroxylamin  compounds:  CeH5.N02+2H2 
=  C6H5.NH.OH  +  H20;  and  then  to  amido- compounds:  C6H5.NH.- 
OH  +  H2=C6H5.NH2+H2O  (p.  419). 

Mono-nitro-benzene — Nitro-benzol — Nitro-benzene — Essence  of 
Mirbane  —  CeHs.NC^  —  is  obtained  by  the  moderated  action  of  fu- 
ming HNOs,  or  of  a  mixture  of  HNOa  and  H2SO4  on  benzene. 

It  is  a  yellow,  sweet  liquid,  with  an  odor  of  bitter  almonds;  sp. 
gr.  1.209  at  15°  (59°  F.);  boils  at  213°  (415.4°  F.);  almost  insol- 
uble in  water;  very  soluble  in  alcohol  and  in  ether.  Concentrated 
H2SO4  dissolves,  and,  when  boiling,  decomposes  it.  Boiled  with 
fuming  HNOs,  it  is  converted  into  dinitro-benzenes.  It  is  converted 
into  anilin  by  reducing  agents. 

It  has  been  used  in  perfumery  as  artificial  essence  of  bitter  al- 
monds; but  as  inhalation  of  its  vapor,  even  largely  diluted  with  air, 
causes  headache,  drowsiness,  difficulty  of  respiration,  cardiac  irregu- 
larity, loss  of  muscular  power,  convulsions,  and  coma,  its  use  for 
that  purpose  is  to  be  condemned.  Taken  internally,  it  is  an  active 
poison. 

Nitro-benzene  may  be  distinguished  from  oil  of  bitter  almonds 
(benzoic  aldehyde)  by  EbSO^  which  does  not  color  the  former;  and 
by  the  action  of  acetic  acid  and  iron  filings,  which  convert  nitro- 
benzene into  anilin,  whose  presence  is  detected  by  the  reactions  for 
that  substance  (p.  420). 

Dinitrobenzenes.  —  The  three  dinitrobenzenes  are  produced  by 
boiling  the  mono -nitro  compound  with  fuming  HNOs.  The  meta- 
compound  predominates,  and  may  be  separated  by  fractional  crys- 
tallization from  alcohol.  It  crystallizes  in  plates,  fusible  at  90° 
(194°  F.),  and  is  used  in  the  preparation  of  certain  dyes,  and  of  ex- 
plosives, such  as  roburite,  sicherheit,  etc.  The  gases  resulting  from 
such  explosives  are  poisonous. 

Nitrotoluenes.  — CeELi.CHa.NCb — The  o-  and  p-  compounds  are  pro- 
duced together  by  nitration  of  toluene,  and  exist  in  the  commercial 
nitro -benzene.  They  may  be  separated  by  fractional  distillation,  the 

27 


418  MANUAL    OP    CHEMISTRY 

o-  compound  boiling  at  218°  (424.4°  P.),  and  the  p-  at  230°  (446° 
P.).  By  reduction  they  yield  the  corresponding  toluidins,  largely 
used  in  the  color  industry. 

Nitro-phenols  —  Mononitro-phenols  —  C6H4(NO2)OH  —  (1  —  2) , 
(1  —  3)  and  (1—4)  are  formed  by  the  action  of  HNOa  on  C6H5.OH. 
The  ortho  compound  (1 — 2)  crystallizes  in  large  yellow  needles,  spar- 
ingly soluble,  and  capable  of  distillation  with  steam.  The  meta  and 
para  compounds  are  both  colorless,  non-volatile,  crystalline  bodies. 
Methyl  chlorid  converts  nitrophenols  into  the  corresponding  nitro- 
anisols,  C6H4.OCH3.N02,  and  ethyl  iodid  into  nitrophenetols,  C6H4- 
OC2H5.NO2,  which  by  reduction  yield  anisidins  and  phenetidins 
(p.  423).  Two  dinitro-phenols,  C6H3.OH(N02)2(2-4>,  and  C6H3.OH- 
(NO2)2(2-6>are  obtained  by  the  action  of  strong  nitric  acid  on  phenol 
or  on  ortho-  or  para-mononitro  phenol.  They  are  both  solid, 
crystalline  substances,  converted  by  further  nitration  into  picric 
acid. 

Trinitro-phenols— CeH2(N02)3OH.— Two  are  known;  (1)  Picric 
acid — Carbazotic  acid — Trinitro-phenic  acid — (N02)  in  2 — 4 — 6.  It 
is  formed  by  nitration  of  phenol,  or  of  1 — 2 — 4  or  1 — 2 — 6  dinitro- 
phenols,  and  also  by  the  action  of  HNOs  on  indigo,  silk,  wool,  resins, 
etc.  It  crystallizes  in  yellow  plates  or  prisms,  odorless,  intensely  bitter 
(7ri/cpos  =  bitter) ;  acid  in  reaction;  sparingly  soluble  in  water,  very 
soluble  in  alcohol,  ether,  and  benzene;  it  fuses  at  122.5°  (252.5  F.), 
and  may,  if  heated  with  caution,  be  sublimed  unchanged;  but,  if 
heated  suddenly  or  in  quantity,  it  explodes  with  violence.  It  be- 
haves as  a  monobasic  acid,  forming  salts,  which  are  for  the  most  part 
soluble,  yellow,  crystalline,  and  decomposed  with  explosion  when 
heated. 

Picric  acid  colors  silk  and  wool  yellow.  It  is  used  as  a  reagent 
for  the  alkaloids,  with  many  of  which  it  forms  crystalline  precipitates, 
as  it  also  does  with  many  other  substances.  It  is  sometimes  added 
to  beer  and  to  other  food  articles,  to  communicate  to  them  either  a 
bitter  taste  or  a  yellow  color.  Its  solutions  give  yellow,  crystalline 
precipitates  with  K  salts;  green  precipitates  with  ammoniacal  CuS04; 
and  an  intense  red  color  when  warmed  with  alkaline  KCN  solution. 
It  is  poisonous, 

Nitro-cresols — Cells. CHs. OH. N02  . — The  o-  and  p-  compounds 
are  known.  They  are  readily  converted  into  the  corresponding  di- 
nitro  compounds,  C6H2.CH3.OH.(N02)2.  The  2-6  dinitro  compound 
is  used  as  a  dye  in  the  form  of  its  sodium  salt,  under  the  name  Vic- 
toria orange,  or» saffron  surrogate.  It  is  poisonous. 

The  nitroso-phenols  are  obtained  by  the  action  of  nitrous  acid 
upon  the  phenols;  or  by  the  action  of  hydroxylammonium  chlorid 
upon  the  quinones. 


NITROGEN  -CONTAINING    DERIVATIVES    OF    BENZENE          419 
p-  Nitro  so-  phenol  —  Quinoxim  —  CeELt.COHjd^NOJu),   or 


I        —(pp.  334,  396),  crystallizes   in   needles,   and   explodes 

when     heated.      Dinitroso  -  resorcinol  —  CeH2(  OH)  2^.3)^0)2(4.6)  is  a 
brown,  explosive  substance,  used  as  a  green  dye,  solid  green. 

Nitro-acids,  such  as  O-,  m-,  and  p-nitro-benzoic  acids,  CeH^- 
COOH.NO2,  etc.,  are  known.     They  yield  amido-acids  by  reduction. 


/    HYDROXYLAMIN    COMPOUNDS. 

Compounds  derived  from  hydroxylamin  by  substitution  of  phenyl- 
alkyl  radicals  for  extra-hydroxyl  hydrogen  are  formed  as  intermediate 
products  of  reduction  of  the  nitro-benzenes  (pp.  417,  428). 

/3-Phenylhydroxylamin — CeHs.NC^jj  — is  an  intermediate  product 
of  reduction  between  nitro-benzene  and  amido-benzene :  :  CeHs.NO2-f- 
2H2=C6H5.N<^H-f-H20,  and  C6H5.N02+3H2=C6H5.NH2+2H2O.  It 

is  readily  oxidized  to  nitroso- benzene  and  other  products,  and  it  re- 
duces Fehling's  solution  and  ammoniacal  AgNOs  solution.  Mineral 
acids  cause  its  intramolecular  rearrangement  to  p-amido- phenol: 

C6H5.N<^H=C6H4(OH)(I)(NH2)(4).      With  nitrous   acid   it   forms   a 

nitroso  derivative  :  C6H5.N<^Q.  It  is  a  crystalline  solid;  f.  p.  81°; 
and  forms  a  crystalline,  colorless  hydrochlorid. 


AMIDO  -  COMPOUNDS . 

The  amido-benzenes  are  the  counterparts  of  the  aliphatic  primary 
monamins  (p.  326).  They  are  obtained  by  reduction  of  the  corre- 
sponding nitro-compounds.  The  reaction  is,  with  moderate  reduction, 
not  so  simple  as  is  expressed  by  the  equation:  CeHs.NO2-h3H2  = 
Cells. NH2+  2H2O,  but  several  important  intermediate  products  are 
formed  (pp.  417,  428,  and  above). 

Anilin — Amido-benzene  — Amido  -benzol — Phenylamin  — Kyanol 
—Cristallin  —  Cells. NH2  —  exists  in  small  quantity  in  coal-tar,  and 
is  one  of  the  products  of  the  destructive  distillation  of  indigo.  It  is 
prepared  by  the  reduction  of  nitro-benzene  by  hydrogen:  CeHs.(NO2) 
-f3H2=C6Hs(NH2)+2H2O  (see  above) ;  the  hydrogen  being  liberated 
in  the  nascent  state  in  contact  with  nitro-benzene  by  the  action  of 
iron  filings  on  acetic  acid. 

Pure  anilin  is  a  colorless  liquid;  has  a  peculiar,  aromatic  odor, 
and  an  acrid,  burning  taste;  sp.  gr.  1.02  at  16°  (60.8°  F) ;  boils  at 
184.8°  (364.6°  F.);  crystallizes  at  —8°  (17.6°  F.);  soluble  in  31 


422  MANUAL    OF    CHEMISTRY 

in  chlorinated  lime  solution,  assumes  a  turbid,  dirty  red  color,  and 
on  addition  of  ammonia  an  indigo -blue. 

By  the  further  substitution  of  a  group  (CHs)  in  acetanilid,  methyl- 
acetanilid,  or  exalgine,  C6H5.N(CH3).C2H3O,  is  produced.  It  is 
formed  by  the  action  of  methyl -iodid  upon  sodium  acetanilid,  Cells. - 
NNa.C2HsO.  It  is  a  crystalline  solid,  sparingly  soluble  in  H^O, 
readily  in  dilute  alcohol.  Its  odor  is  faintly  aromatic. 

Three  acettoluids,  C6H4\NH3(CoH3O)»  ortho-,  meta-,  and  para-, 
are  also  known.  The  para-  and  meta-  compounds  seem  to  be  almost 
inert,  while  the  ortho-  compound  is  highly  poisonous. 

The  "anilin  dyes"  now  so  extensively  used,  even  those  made  from 
anilin,  are  not  compounds  of  anilin,  but  are  salts  of  bases  formed 
from  it,  themselves  colorless,  called  rosanilins  (see  p.  450). 

Phenylamins  —  Phenylenediamins,  etc. — Anilin  is  the  simplest 
representative  of  a  large  class  of  substances.  It  may  be  considered 
as  benzene  in  which  H  has  been  replaced  by  NH2,  thusi  Cells. NH2. 
Its  superior  homologues,  derivable  from  the  superior  homologues  of 
benzene,  each  have  at  least  three  isomeres,  ortho-,  meta-,  and  para-, 
according  to  the  orientation  of  the  groups  NH2  and  C«H2*+i.  Anilin 
may  also  be  considered  as  ammonia  in  which  H  has  been  replaced 
by  phenyl,  CeHs,  thus  being  a  primary  monamin  (see  p.  326), 

C6g^}N.     The  remaining  two  H  atoms  may  be  replaced  by  other 

radicals  to  form  an  almost  infinite  variety  of  secondary  and  tertiary 
phenylamins,  precisely  as  in  the  case  of  the  aliphatic  monamins. 
Possibly  some  of  the  ptomains  are  phenylamins.    Mydin,  CsHnNO, 

/OTT 

for  example,  is  supposed  to  be  oxyphenyl  ethylamin,  CeH^Qjj,,  cn2.- 
NH2.  It  is  a  powerful  base,  strongly  alkaline,  has  an  ammoniacal 
odor,  is  a  strong  reducing  agent,  is  non-poisonous,  and  is  produced 
after  continued  putrefaction  at  low  temperatures. 

Again,  it  is  clear  that,  considering  anilin  as  amido- benzene,  the 
substitution  of  NH2  is  not  limited  to  the  introduction  of  one  such 
group.  There  may  be  three  phenylenediamins,  CeH^NEbh,  ortho-, 
meta-,  and  para-,  three  triamido  benzenes,  -CeHsCNEfeJa,  etc. 

Meta-phenylenediamin  is  converted  into  triamido  azobenzene, 
Bismark  brown,  by  nitrous  acid,  and  is,  therefore,  used  as  a  test 
for  nitrites  in  water. 

Phenylcarbylamin  —  Phenyl  Isocyanid  —  Isobenzonitril  — 
Cells. N  !  C — (p.  340)  is  formed  when  chloroform  is  heated  with  anilin 
and  caustic  potash  in  alcoholic  solution  (p.  235).  It  is  a  liquid, 
having  a  most  persistent,  disagreeable  odor.  Nascent  hydrogen  con- 
verts it  into  methyl  anilin.  Heated  to  220°  (428°  F.),  it  is  converted 
into  its  isomere,  benzonitril,  or  cyanobenzene,  C6H5.CN,  which  is  a 


NITROGEN  -  CONTAINING    DERIVATIVES    OF    BENZENE          423 

liquid  having  an  odor  of  bitter  almonds;  also  formed  by  distilling 
potassium  benzene  sulfonate  with  potassium  cyanid. 

X/"\TT 

Amido-phenols  —  CeH4\NH2 — Three  are  known,  ortho-,  meta-, 
and  para-,  obtained  by  the  action  of  reducing  agents  upon  the  corre- 
sponding nitro-compounds.  Their  methylic  ethers,  GeH^^n^ 
are  known  as  anisidins;  and  their  ethylic  ethers,  CeHX^H*3^  as 
phenetidins. 

By  the  action  of  glacial  acetic  acid  upon  paraphenetidin,  an  ace  to- 
derivative,  para-acetophenetidin,  CellUC^HsJd)  .(NH.C2H3O)U),  is 
formed.  It  is  used  as  an  antipyretic,  under  the  name  phenacetine, 
and  is  a  colorless,  odorless,  tasteless  powder,  sparingly  soluble 
in  H2O,  readily  soluble  in  alcohol,  fuses  at  135°  (275°  F.).  Its 
hot  aqueous  solution  is  colored  violet,  changing  to  ruby-red,  by 
chlorin  water.  The  corresponding  anisidin,  para-acetoanisidin,  CeH*- 
(OCHaK)  (NH.C2H30)(4),  methacetine,  has  also  been  used  as  a 
therapeutic  agent.  It  crystallizes  in  white,  shining,  tasteless,  odor- 
less scales,  fuses  at  127°  (260.6°  F.),  sparingly  soluble  in  H2O, 
readily  soluble  in  alcohol.  It  responds  to  the  indophenol  reaction 
(p.  421). 

Aromatic  acid  amids  are  formed  by  methods  similar  to  those  by 
which  the  aliphatic  amids  are  produced,  and  resemble  them  in  their 
reactions  (p.  346).  Thus  benzamid,  or  benzoyl  amid,  C6Hs.CO.NH2, 
is  formed  by  the  action  of  benzoyl  chlorid  upon  ammonia,  CeHs.CO.- 
Cl+NH3=HCl+CflH5.CO.NH2,  as  a  crystalline  solid,  fusible  at  130° 
(266°  F.).  Two  formula  of  benzamid  are  possible:  the  amid  for- 
mula, C6H5.C^oH2}  and  the  imid  formula,  C6H5.C^oH-  Derivatives 
corresponding  to  each  are  known. 

The  aromatic  amido-acids  greatly  exceed  the  aliphatic  (p.  361) 
in  number  and  variety.  They  are:  (I)  Amido-phenyl  acids,  which 
may  be  considered  either  as  aromatic  acids,  in  which  a  ring  hydro- 
gen atom  (or  atoms)  has  been  replaced  by  NH2;  or  as  aliphatic  acids, 
in  which  amido-phenyl  (C6H4.NH2)'  has  replaced  H  in  a  hydrocarbon 
group;  (2)  phenyl-amido  acids,  considered  either  as  aromatic  acids, 
in  which  NH2  replaces  H  in  a  hydrocarbon  group  of  a  lateral  chain, 
or  as  amido- aliphatic  acids,  in  which  phenyl  (CeHs)'  has  been  substi- 
tuted for  H  in  a  hydrocarbon  group;  (3)  anilido-acids  —  aliphatic 
amido-acids  in  which  phenyl  has  been  substituted  for  H  in  NH2. 
In  this  class  are  included  the  anilids  of  the  dicarboxylic  acids 

(p.  421),  e.  g.,  oxanilic  acid,  OC^coOH^;  W  amic  acids  <P-  346>' 
derived  from  the  dicarboxylic  aromatic  acids  by  substitution  of 
NH2  for  OH  in  one  carboxyl  group.  Besides  these  there  are 


422  MANUAL    OF    CHEMISTRY 

in  chlorinated  lime  solution,  assumes  a  turbid,  dirty  red  color,  and 
on  addition  of  ammonia  an  indigo -blue. 

By  the  further  substitution  of  a  group  (CHa)  in  acetanilid,  methyl- 
acetanilid,  or  exalgine,  CeHs.NXCHaJ.C^sO,  is  produced.  It  is 
formed  by  the  action  of  methyl -iodid  upon  sodium  acetanilid,  CeHs.- 
NNa.C2HsO.  It  is  a  crystalline  solid,  sparingly  soluble  in  H2O, 
readily  in  dilute  alcohol.  Its  odor  is  faintly  aromatic. 

Three  acettoluids,  CeH4\NH3(CoH3O)'  ortn°-»  meta-,  and  para-, 
are  also  known.  The  para-  and  meta-  compounds  seem  to  be  almost 
inert,  while  the  ortho-  compound  is  highly  poisonous. 

The  "anilin  dyes"  now  so  extensively  used,  even  those  made  from 
anilin,  are  not  compounds  of  anilin,  but  are  salts  of  bases  formed 
from  it,  themselves  colorless,  called  rosanilins  (see  p.  450) . 

Phenylamins  —  Phenylenediamins,  etc. — Anilin  is  the  simplest 
representative  of  a  large  class  of  substances.  It  may  be  considered 
as  benzene  in  which  H  has  been  replaced  by  NH2,  thust  C6H5.NH2. 
Its  superior  homologues,  derivable  from  the  superior  homologues  of 
benzene,  each  have  at  least  three  isomeres,  ortho-,  meta-,  and  para-, 
according  to  the  orientation  of  the  groups  NH2  and  C*H2«+i.  Anilin 
may  also  be  considered  as  ammonia  in  which  H  has  been  replaced 

by    phenyl,   CeHs,   thus   being   a   primary   monamin   (see   p.   326), 
r*  TT  *^ 
^JN.     The  remaining  two  H  atoms  may  be  replaced  by  other 

radicals  to  form  an  almost  infinite  variety  of  secondary  and  tertiary 
phenylamins,  precisely  as  in  the  case  of  the  aliphatic  monamins. 
Possibly  some  of  the  ptomams  are  phenylamins.    Mydin,  CgHnNO, 

/OTT 

for  example,  is  supposed  to  be  oxyphenyl  ethylamin,  CeH4^CH2  CH2  . 

NH2.  It  is  a  powerful  base,  strongly  alkaline,  has  an  ammoniacal 
odor,  is  a  strong  reducing  agent,  is  non- poisonous,  and  is  produced 
after  continued  putrefaction  at  low  temperatures. 

Again,  it  is  clear  that,  considering  anilin  as  amido -benzene,  the 
substitution  of  NH2  is  not  limited  to  the  introduction  of  one  such 
group.  There  may  be  three  phenylenediamins,  C6H4(NH2)2,  ortho-, 
meta-,  and  para-,  three  triamido  benzenes,  -CeHsCNEkJs,  etc. 

Meta-phenylenediamin  is  converted  into  triamido  azobenzene, 
Bismark  brown,  by  nitrous  acid,  and  is,  therefore,  used  as  a  test 
for  nitrites  in  water. 

Phenylcarbylamin  —  Phenyl  Isocyanid  —  Isobenzonitril  — 
Cells. N  I  C — (p.  340)  is  formed  when  chloroform  is  heated  with  anilin 
and  caustic  potash  in  alcoholic  solution  (p.  235).  It  is  a  liquid, 
having  a  most  persistent,  disagreeable  odor.  Nascent  hydrogen  con- 
verts it  into  methyl  anilin.  Heated  to  220°  (428°  F.),  it  is  converted 
into  its  isomere,  benzonitril,  or  cyanobenzene,  C6H5.CN,  which  is  a 


NITROGEN  -CONTAINING    DERIVATIVES    OF    BENZENE          423 

liquid  having  an  odor  of  bitter  almonds;   also  formed  by  distilling 
potassium  benzene  sulfonate  with  potassium  cyanid. 

/OTT 

Amido-phenols  —  C6H4\NH2  —  Three  are  known,  ortho-,  meta-, 
and  para-,  obtained  by  the  action  of  reducing  agents  upon  the  corre- 
sponding mtro-compounds.  Their  methylic  ethers,  CeH4<^Njj2  3^ 


/ofr*  TT 
are  known  as  anisidins  ;  and  their  ethylic  ethers,  CeH 


phenetidins. 

By  the  action  of  glacial  acetic  acid  upon  paraphenetidin,  an  ace  to- 
derivative,  para-acetophenetidin,  C6H4(OC2H5)(i)  .(NH.C2H3O)U),  is 
formed.  It  is  used  as  an  antipyretic,  under  the  name  phenacetine, 
and  is  a  colorless,  odorless,  tasteless  powder,  sparingly  soluble 
in  H2O,  readily  soluble  in  alcohol,  fuses  at  135°  (275°  F.).  Its 
hot  aqueous  solution  is  colored  violet,  changing  to  ruby-red,  by 
chlorin  water.  The  corresponding  anisidin,  para-acetoanisidin,  CelLi- 
(OCH3)(i)  (NH.C2H30)(4),  methacetine,  has  also  been  used  as  a 
therapeutic  agent.  It  crystallizes  in  white,  shining,  tasteless,  odor- 
less scales,  fuses  at  127°  (260.6°  F.),  sparingly  soluble  in  H2O, 
readily  soluble  in  alcohol.  It  responds  to  the  indophenol  reaction 
(p.  421). 

Aromatic  acid  amids  are  formed  by  methods  similar  to  those  by 
which  the  aliphatic  amids  are  produced,  and  resemble  them  in  their 
reactions  (p.  346).  Thus  benzamid,  or  benzoyl  amid,  C6H5.CO.NH2, 
is  formed  by  the  action  of  benzoyl  chlorid  upon  ammonia,  CeHs.CO.- 
C1+NH3=HC1+C6H5.CO.NH2,  as  a  crystalline  solid,  fusible  at  130° 
(266°  F.).  Two  formulae  of  benzamid  are  possible:  the  amid  for- 

mula, C6H5.C^oH2>  and  the  imid  formula,  C6H5.C^oH-  Derivatives 
corresponding  to  each  are  known. 

The  aromatic  amido-acids  greatly  exceed  the  aliphatic  (p.  361) 
in  number  and  variety.  They  are:  (1)  Amido-phenyl  acids,  which 
may  be  considered  either  as  aromatic  acids,  in  which  a  ring  hydro- 
gen atom  (or  atoms)  has  been  replaced  by  NH2;  or  as  aliphatic  acids, 
in  which  amido-phenyl  (CeEU.NH^)'  has  replaced  H  in  a  hydrocarbon 
group;  (2)  phenyl-amido  acids,  considered  either  as  aromatic  acids, 
in  which  NH2  replaces  H  in  a  hydrocarbon  group  of  a  lateral  chain, 
or  as  amido-  aliphatic  acids,  in  which  phenyl  (CeEU)'  has  been  substi- 
tuted for  H  in  a  hydrocarbon  group;  (3)  anilido-acids  —  aliphatic 
amido-acids  in  which  phenyl  has  been  substituted  for  H  in  NH2. 
In  this  class  are  included  the  anilids  of  the  dicarboxylic  acids 

(p.  421),  e.  g.,  oxanilic  acid,  OC<$oaEL**}  ',  (4)  amic  acids  (p.  346), 
derived  from  the  dicarboxylic  aromatic  acids  by  substitution  of 
NH2  for  OH  in  one  carboxyl  group.  Besides  these  there  are 


424 


MANUAL    OP    CHEMISTRY 


amido-  acids  referable  to  1  and  3,  in  which  the  radical  benzoyl, 
C6H5.CO,  takes  the  place  of  phenyl,  C6H5.  The  structure  of  these 
several  acids  is  shown  by  the  following  formulae: 


CH2.COOH 


NH2 


CH2.CH(NH2).COOH 


COOH 


o-Amido-phenyl 
acetic  acid. 


(2) 

/9  Phenyl,  a  amido- 
propionic  acid. 


(3) 

a  Anilido- 
propionic  acid. 


Amido-phenyl  Acids,  of  which  anthranilic,  or  o-amido-benzoic 
acid,  C6H4(COOH)(i)(NH2)(2),  is  the  type,  are  formed  by  reduction 
of  the  corresponding  nitro-benzoic  acids.  Nitrous  acid  converts  them 
into  the  corresponding  oxyacids.  Thus  anthranilic  acid  yields  sali- 
cylic acid.  The  o-  acids  exhibit  a  great  tendency  to  the  formation  of 
lactams  (p.  362),  some  of  which  are  indigo  derivatives,  as  oxindole, 

/CH2.CO(x) 
the  lactam  of  o-  amido  -phenyl  acetic  acid,  C6H4\  ,    and   diox- 

x  -  NH(2) 

/CH(OH)CO(I) 
indole,  the  lactam  of  o-  amido-  mandelic  acid,  CeEUv  I       ,  (p. 

x  -  NH(2) 

411).     Isatin,  a  product  of  oxidation  of  indigo,  is  the  lactam  of  o- 


amido  -benzoyl  -formic    acid,    CeH4 


\ 

X— 


I 
NH(2) 


The   amido-  cinnamic 


acids  are  closely  related  to  quinolin  (p.  468). 

Phenyl-alanin  (p.  364),  is  a  phenyl-amido  acid:  /3-phenyl-a- 
amido-propionic  acid  (formula  above),  which  exists  in  certain  lu- 
pines, and  is  a  product  of  decomposition  of  the  proteins.  Its  corre- 
sponding p-oxyphenyl  derivative  is 

Tyrosin  —  p-Oxyphenyl  alanin  —  (HO)(4,C6H4.CH2.CH(NH2)  .- 
COOH  —  one  of  the  earliest  known  products  of  protein  decomposition. 
Tyrosin  is  formed  from  proteins,  particularly  from  casein,  by  the 
action  of  proteolytic  enzymes,  and  during  putrefaction,  and  is  also 
formed  from  them  by  boiling  with  HC1  or  H2S04,  or  by  fusion  with 
KHO,  always  accompanied  by  leucin  (p.  364).  It  exists  normally  in 
the  intestine,  and  pathologically  in  the  urine  (q.  v.).  It  has  been 
formed  synthetically,  from  phenyl  -acetaldehyde,  CeHs.CH^.CHO,  by 
conversion  into  phenyl  -alanin,  CeHs.CH^.CHXNH^.COOH  and  p- 
amido-  phenyl  -a-  alanin,  C6H4(NH2)U).CH2.CHNH2.COOH.  It  crystal- 
lizes in  silky  needles,  arranged  in  stellate  bundles,  very  sparingly 
soluble  in  cold  water,  soluble  in  150  parts  of  hot  water,  more  soluble 


NITROGEN -CONTAINING    DERIVATIVES    OF    BENZENE          425 

in  the  presence  of  acids  or  of  alkalies,  insoluble  in  alcohol  and  in 
ether.  It  unites  with  acids  and  bases  to  form  salts.  When  heated  it 
turns  brown  and  gives  off  the  odor  of  phenol;  when  heated  to  270° 
(518°  F.),  it  is  decomposed  into  CO2  and  oxyphenylethyl-amin, 
C6H4(OH).CH2.CH2.NH2,  which  sublimes. 

With  H2SO4,  and  slightly  warmed,  it  dissolves  with  a  transient 
red  color;  the  solution,  cooled,  diluted,  neutralized  with  BaCOs,  and 
filtered;  gives  a  violet  color  with  Fe2Cl6  (Piria's  reaction).  When 
moistened  with  HNOs  and  slowly  evaporated,  it  leaves  a  yellow  resi- 
due, which  forms  a  deep  reddish -yellow  color  with  NaHO  (Scherer's 
reaction).  Heated  wifrh  water  and  a  few  drops  of  Millon's  reagent  it 
gives  a  red  liquid,  and  forms  a  red  precipitate  (Hofmann's  reaction). 

p-Amidophenyl-a-alanin— NH2(4)C6H4.CH2.CH(NH2).COOH— pro- 
duced by  reduction  of  p-nitrophenyl-alanin,  is  both  a  phenyl-amido 
and  an  amido-phenyl  acid. 

Anilido  Acids  derived  from  the  monocarboxylic  acids  are  produced 
by  the  action  of  the  monochlor- acids  upon  anilin,  as  the  aliphatic 
amido- acids  are  obtained  from  ammonia  (p.  362).  Thus  mono- 
chloracetic  acid  and  anilin  yield  anilido -acetic  acid,  or  phenyl  gly- 
cocoll,  CHaCl.COOH+CeHs.NHs^CeHs.NH.CHa.COOH+HCl. 

Hippuric  Acid — Benzoyl-amido-acetic  acid — Benzoyl  glycocoll 
— C6H5.CO.NH.CH2.OOOH— is  similarly  obtained  from  monochlor- 
acetic  acid  and  benzamid:  CH2C1.COOH+C6H5.CO.NH2=C6H5.CO.- 
NH.CH2.COOH+HC1.  It  is  also  formed  by  the  action  of  benzoyl 
chlorid  upon  glycocoll  in  the  presence  of  sodium  hydroxid  :  CH2- 
(NH2).COOH+C6H5.CO.C1=C6H5.CO.CH2.NH.COOH+HC1.  Hip- 
puric acid  exists  in  the  urine  of  the  herbivora;  and  in  human  urine  in 
the  daily  quantity  of  0.29-2.84  grams,  and  in  larger  amount  when 
benzoic  acid,  cinnamic  acid  and  other  aromatic  substances  are  taken. 
It  crystallizes  in  prisms,  colorless,  odorless,  bitter,  sparingly  soluble 
in  water,  readily  soluble  in  alcohol,  fuses  at  187°  (368.6°  F.).  When 
heated  with  acids  or  alkalies  it  is  decomposed  into  benzoic  acid  and 
glycocoll.  Oxidizing  agents  convert  it  into  benzoic  acid,  benzamid 
and  carbon  dioxid.  When  heated  alone  it  gives  off  a  sublimate  of 
benzoic  acid  and  the  odor  of  hydrocyanic  acid.  Its  ferric  salt  is  insol- 
uble, and  is  formed  as  a  brown  precipitate  when  Fe2Cle  is  added  to 
its  solution.  Heated  with  lime  it  forms  benzene  and  ammonia. 

Anilic  Acids  are  anilido  acids  corresponding  to  the  dicarboxylic 
acids.  They  may  be  considered  as  being  formed  by  substitution  of 
the  univalent  remainder  of  the  acid  for  H  in  anilin,  and  therefore  as 
anilids  (p.  421) ;  or  by  substitution  of  phenyl  for  H  in  the  NH2  group 
of  the  amic  acids  (pp.  346,  361).  Thus  oxanilic  acid,  C6H5.NH.CO.- 
COOH,  corresponds  to  oxalic  acid,  COOH.COOH,  and  to  oxamic 
acid,  CONH2.COOH. 


426  MANUAL    OP    CHEMISTRY 

Carbanilic  Acid— 0 :  C\NH  CeH5--the  anilic  acid  corresponding  to 

carbonic  and  carbamic  acids,  and  isomeric  with  phenyl  urethaii 
(p.  347),  is  not  known  in  the  free  state.  Its  esters,  however,  are 
known  as  phenyl  urethans.  A  great  number  of  phenyl-urea  and 
phenyl-guanidin  derivatives  are  also  known. 

Related  to  the  amido  acids  are  the  hydroxamic  acids  and  the 
anil  acids. 

Hydroxamic  Acids  are  derivable  from  the  imid  formula  of  benz- 
amid  (p.  423)  by  substitution  of  OH  for  H  in  the  imid  group. 

Thus  benzhydroxamic  acid,  CeHs.C^Qjj   ,  corresponds  to  benzamid, 

CeHs.C^oH-  Both  H  atoms  in  the  OH  groups  are  replaceable  by 
alkyls  to  form  esters.  Amidoxims  (p.  335)  are  derived  from  the 
hydroxamic  acids  by  substitution  of  NH2  for  OH,  e.  g.,  benzenyl- 

amidoxim,  CeHs.Cv  j^jj2  . 

Anil  Acids  are  anilin  derivatives  of  the  ketone-carboxylic  acids 
(p.  298),  formed  by  the  union  of  anilin  and  the  acid,  with  elimina- 
tion of  water.  Thus  anilin  and  pyroracemic  acid  yield  anil-pyro- 
raccmic  acid  !  060.5 ••N-H.2~r~C>' -0.3. OO . OOOxi1 — xd.2v/~i  Oo-tls. .N  *  \j \ Oxis) .  - 
COOH. 

DIAZO,    DIAZO  AMIDO,   AND    AZO     COMPOUNDS. 

Diazo  compounds  contain  the  group  * — N :  N — ,  united  by  one 
bond  to  an  aromatic  group,  and  by  the  other  to  an  acid  radical. 

Diazoamido  compounds  contain  the  group  — N:N.NH — ,  united  to 
two  aromatic  groups. 

Azo  compounds  contain  the  group — N:N — ,  united  to  two  aro- 
matic hydrocarbon  groups,  or  to  one  aromatic  and  one  aliphatic  hy- 
drocarbon group.  The  derivatives  of  each  of  the  classes  are  produced 
by  substitution  for  hydrogen. 

Diazo  Compounds — Diazobenzene,  CeHs.NrN.H,  does  not  exist 
free;  and  the  diazo  compounds  in  general  readily  undergo  decomposi- 
tion, and  are  hence  largely  used  in  the  preparation  of  a  variety  of 
substitution  products,  and  notably  in  the  manufacture  of  a  great 
number  of  azo-dyes,  to  which  class  most  of  the  so-called  anilin  dyes 
belong. 

The  diazo  compounds  are  produced  by  the  action  of  nitrous  acid 
upon  the  corresponding  anilin  compounds.  Thus  anilin  hydrochlorid 
with  HNO2  forms  diazobenzene  chlorid:  C6H5.NH3C1+HNO2=C6H5.- 
N:N.CH-2H2O.  The  reaction  must  be  conducted  at  a  low  tempera- 
ture, otherwise  the  anilin  compound  will  suffer  the  same  decomposi- 
tion by  HN02  as  do  its  congeners,  the  primary  aliphatic  amins  (p. 


NITROGEN -CONTAINING    DERIVATIVES    OP    BENZENE          427 

328);  i.  e.,  the  N  is  eliminated,  and  a  phenol,  water  and  the  acid 
are  formed:   C6H5.NH3Cl+^NO2=C6H5.0H+N2+H2O-|-flCl. 

The  diazo  compounds  are  mostly  crystalline  solids,  colorless  when 
pure,  but  turning  brown  in  air,  readily  soluble  in  water,  sparingly 
soluble  in  alcohol,  insoluble  in  ether,  and  decomposing  explosively 
when  heated  or  struck.  Their  N  is  readily  displaced  by  H,  OH,  or  the 
halogens  or  cyanogen,  with  formation  of  hydrocarbons,  phenols,  ha- 
loids, and  cyanids,  and  regeneration  of  the  acid.  Thus  diazobenzene 
sulfate  yields  phenol  by  hydration:  C6H5.N:N.HSO4-|-H2O=C6H5.- 
OH+N2+H2S04. 

By  reduction  they  form  hydrazins.  Thus  potassium  diazobenzene 
sulfonate  forms  potassium  benzene -hydrazin  sulfonate:  C6H5.N:N.- 
SO3K+H2  =  C6H5.HN.NH.SO3K. 

Heated  with  aromatic  amins  or  phenols,  they  form  amido-  or 
hydroxyl  azo  compounds,  which,  either  in  their  own  form  or  in 
those  of  their  sulfonic  acids  or  salts,  are  the  azo  dyes. 

Diazoamido  and  Disdiazoamido  Compounds. —  The  diazoamido 
compounds,  containing  the  group  — N:N.NH —  united  to  two  aro- 
matic groups,  are  formed  by  the  action  upon  each  other  of  diazo 
salts  and  primary  or  secondary  amins  in  equal  molecular  proportion. 
Thus  diazoamido  benzene,  CeHs.NrN.NH.CeHs,  is  formed,  as  a  yel- 
low, crystalline,  explosive  solid,  insoluble  in  water,  soluble  in  hot 
alcohol,  by  the  action  of  diazobenzene  nitrate,  or  chlorid,  upon 
anilin:  CeHs.NtNCl+NHs.CGHs^CeHs.N^.NH.CeHs+HCl. 

The  most  notable  property  of  these  substances  is  their  transfor- 
mation, by  intramolecular  rearrangement,  into  the  isomeric  p-azo- 
amido  compounds.  Thus  diazoamido  benzene  becomes  p-azo- amido 
benzene,  CeHsNtNCeH^NH^).  This  intramolecular  transposition 
takes  place  slowly  in  the  presence  of  traces  of  anilin  salts,  at  the 
ordinary  temperature. 

The  disdiazoamido  compounds,  containing  the  group  — NrN.NH.- 
N:N — ,  are  formed  under  the  same  conditions  as  the  diazoamido 
compounds,  except  that  two  molecules  of  the  diazo  salt  are  taken 
for  one  of  the  amin:  2C6H5.N:NC1+NH2.C6H5=C6H5.N:N.N(C6H5).- 
N:N.C6H5+2HC1. 

Azo  Compounds. — The  azo  compounds  contain  the  same  group, 
— N:N — ,  as  the  diazo  compounds,  but  they  differ  from  the  latter  in 
that  the  two  valences  are  both  satisfied  by  hydrocarbon  groups; 
either  both  aromatic,  as  in  azobenzene,  CeHs.NiN.CGHs,  or  one 
aromatic  and  one  aliphatic,  as  in  benzene  azo-methane,  CoHs.NrN.- 
CH3.  They  are  "mixed,"  "symmetric,"  and  "unsymmetric,"  accord- 
ing as  they  contain  an  aromatic  and  an  aliphatic  group,  or  two  like 
aromatic  groups,  or  two  unlike  aromatic  groups.  In  designating  the 
orientation  of  substituted  groups  the  — N :  N —  attachments  are  con- 


428  MANUAL    OF    CHEMISTRY 

sidered  as  occupying  the  (1)  position  in  both  hydrocarbon  groups, 
and  the  positions  of  substitution  in  one  ring  are  indicated  by  2,  3, 
etc.,  and  those  in  the  other  by  2',  3',  etc. 

The  azo  compounds  are  formed:  (1)  By  moderate  reduction  of 
nitro- aromatic  compounds  in  alkaline  solution.  The  reaction  takes 
place  in  two  stages,  an  azoxy  compound  being  first  formed  and  then 
further  reduced.  Thus  nitro -benzene  forms,  first  azoxybenzene,  then 

azobenzene:  2C6H5.N02+3H2=C6H5.N/    ^N.C6H5+3H2O,  and  then 

CeHs.N/^N.CYHs  +  H2  =  C6H5.N:N.C6H5  +  H20.  The  reduction 
readily  progresses  further,  and  always  does  so  in  acid  solutions,  with 
formation,  first  of  a  hydrazo  product  (below),  and  finally  an  amido 
derivative  (pp.  417,  419).  Thus  azobenzene  forms,  first,  hydrazo- 
benzene,  or  symmetrical  diphenyl  hydrazin,  and  then  anilin:  C6H5.- 
N:N.C6H5+H2=C6H5.NH.NH.C6H5,  and  CeHs.NH.NH.CeHs+Hs^ 
2C6H5.NH2.  (2)  By  reduction  of  the  azoxy  compounds.  (3)  The 
amido  derivatives  of  the  azo  hydrocarbons  are  technically  manufac- 
tured by  molecular  rearrangement  of  the  diazoamido  compounds 
(p.  427),  or  (4)  by  acting  upon  the  tertiary  anilins,  or  upon  the  m- 
diamins,  with  diazo  salts. 

The  azo  compounds  are  much  more  stable  than  the  diazo  com- 
pounds. The  hydrocarbons,  such  as  azobenzene,  Cells. NiN.CeHs, 
are  highly  colored  crystalline  solids,  which  are  not  basic,  and  do  not 
act  as  dyes.  They  are  sparingly  soluble  in  water,  readily  soluble  in 
alcohol  and  in  ether.  Their  most  important  derivatives  are  the 
amido -azo  compounds,  which  are  highly  colored  and  strongly  basic, 
crystalline  solids,  whose  solutions  have,  however,  no  dyeing  power. 
But  they  combine  readily  with  salt-forming  groups,  notably  to  form 
sulfonic  acids,  which  constitute  many  of  the  most  extensively  used 
"anilin  dyes." 

p-Amido-azobenzene  —  CeEU.NtNXCGHO  (NH2)(4)  —  prepared  by 
the  methods  given  above,  is  the  starting  point  in  the  manufacture  of 
several  yellow,  orange,  and  brown  "diazo  dyes,"  and  of  the  "inuline 
dyes."  It  forms  yellow  needles,  fusing  at  123°  (253.4°  F.) . 


HYDRAZIN    COMPOUNDS. 

The  aromatic  hydrazins  are  derived  from  the  hypothetical  diamid, 
H2N.NH2  (p.  105),  by  substitution  of  hydrocarbon  or  other  aro- 
matic radicals  for  one  or  more  of  the  hydrogen  atoms  (p.  337). 

Hydrazo-benzene  —  sym.  Diphenyl  -  hydrazin  —  C6H5.NH.NH.- 
CoHs— is  obtained  by  moderate  reduction,  as  with  zinc  dust  or  sodium 
amalgam,  of  azobenzene:  C6H5.N: 


NITROGEN  -CONTAINING    DERIVATIVES    OF    BENZENE          429 

It  forms  colorless  crystals,  having  the  odor  of  camphor,  fusible  at 
132°  (267.8°  F.),  insoluble  in  water,  soluble  in  alcohol  and  in  ether. 
It  readily  oxidizes  to  azobenzene.  Strong  reducing  agents  break  it 
up  into  two  molecules  of  anilin.  It  is  not  basic;  but,  when  treated 
with  strong  acids,  it  suffers  molecular  rearrangement,  with  formation 
of  benzidin,  or  p^-diamido-diphenyl  (p.  447),  NH^.CeH^CeELi.- 
NH»4>. 

The  unsymmetrical  hydrazins  resemble  each  other  in  their  prop- 
erties and  methods  of  formation,  but  differ  from  the  symmetrical 
compounds,  notably  in  that,  containing  the  —  NH.NH2  group,  they 
are  mouacid  bases,  forming  salts  corresponding  to  those  of  ammonia 
and  the  amins. 

Phenylhydrazin  —  Cells.  NH.NEk—  is  formed  by  reduction  of  the 
diazo  salts,  of  the  diazo-amido  compounds,  or  of  the  nitroso-  amins. 
Thus  stannous  chlorid  and  diazobenzene  chlorid  yield  phenylhydrazin 
hydrochloric!  :  C6H5N:NC1  +  2SnCl2  +  4HC1  =  C6H5.NH.NH3C1  + 
2SnCl4.  Zinc  dust  and  acetic  acid  decompose  diazoamido  -benzene 
into  phenylhydrazin  and  anilin:  C6H5.N:N.NH.C6H5+2H2=C6H5.- 


Phenylhydrazin  is  a  yellow  oil,  which  crystallizes  at  23°  (73.4°  F.  )  , 
and  boils  at  242°  (467.6°  F.)  with  partial  decomposition,  or  at  120° 
(248°  F.),  without  decomposition,  under  12mm.  pressure.  It  re- 
duces Fehling's  solution,  or  when  boiled  with  CuS04  it  liberates 
nitrogen  and  forms  benzene.  Sodium  displaces  the  imid  H  to  form 
a  sodium  phenylhydrazin:  CaH5.NaN.NH2.  The  alkyl  haloids  cause 
substitution  of  alkyls  for  both  amid  and  imid  H,  forming  a  and  (3 
phenylalkyl  hydrazins.  One  of  the  latter,  /?methyl-phenylhydrazin, 
CeHs.NH.NH.CHs,  is  an  intermediate  product  in  the  formation  of 
antipyrin  from  phenylhydrazin.  Heated  to  200°  (392°  F.)  with 
fuming  HC1,  phenylhydrazin  is  converted  into  p-phenylene-diamin  : 
C6H5.NH.NH2  =  NH2.C6H4.NH2. 

Phenyl-hydrazones  and  Osazones.  —  A  most  important  action  of 
phenylhydrazin  is  that  with  aldehydes  and  ketones,  and  with  aldo- 
and  keto-  alcohols,  and  aldehyde  and  ketone  acids  and  their  esters, 
in  which  the  bivalent  remainder  ^N.NH.CeHs  takes  the  place  of 
oxygen  in  the  aldehyde  or  ketoue  group,  with  the  formation  of 
phenyl-hydrazones  and  osazones,  in  much  the  same  manner  as  the 
aldoxims  and  ketoxims  are  formed  from  the  aldehydes  and  ketones 
(pp.  360,  361).  The  formation  of  these  derivatives  is  utilized  to 
identify  the  aldehydes  and  ketones  and,  notably,  the  aldoses  and 
ketoses  (p.  264,  also  "phenylhydrazin  reaction"). 

The  phenyl-hydrazones  and  osazones  are  formed  by  a  variety  of 
methods,  usually  by  heating  the  aldehyde  or  ketone  compound  with 
phenylhydrazin  hydrochlorid  in  presence  of  sodium  acetate.  In  the 


430  MANUAL    OP    CHEMISTRY 

formation  of  the  aldehydrazones  and  ketohydrazones  the  reaction 
takes  place  with  elimination  of  water  according  to  the  equations: 
CH3.CH2.CHO  -I-  H2N.NH.C6H5  =  CH3.CH2.CH:N.NH.C6H5  +  H2O, 
and  CH3.CO.CH3+H2N.NH.C6H5  =  CH3.C:  (N.NH.C6H5).CH3-hH2O. 
In  the  formation  of  the  osazones  of  the  aldoses  and  ketoses  two 
molecules  of  phenylhydrazin  react  with  one  of  the  sugar,  with  elimi- 
nation of  water.  In  the  first  stage  of  the  reaction  a  hydrazone  is 
formed  as  with  the  aldehydes  and  ketones.  Thus  with  glucose  and 
fructose  respectively  (pp.  268,  269) : 

CHO  CH:N.NH.C6H5 

(CHOH)4+H2N.NH.CeH5=(CHOH)4  +H2O,  and 

CH2OH  CH2OH 

CH2OH  CH2OH 

CO  C:N.NH.C6H5 

(CHOH)3+H2N.NH.C6H5=(CHOH)3          -fH2O; 

CH2OH  CH2OH 

The  CHOH  or  CH2OH  group  vicinal  to  the  first  substitution  then 
becomes  oxidized  to  CO  or  CHO,  and  a  second  =N.NH.CeH5  group 
is  substituted  for  the  O  to  form  the  osazone  : 

CH:N.NH.C6H5  CH:N.NH.C6H5 

CO  C:N.NH.C6H5 

(CHOH)3  +H2N.NH.C6H5=(CHOH)3  +H2O,  and 

CH2OH  CH2OH 

CHO  CH:N.NH.C6H5 

C  :N.NH.C6H5  C  :N.NH.C6H5 


A 


HOH)3          +H2N.NH.C0H5=(CHOH):{  +H2O. 

CH2OH  CH2OH 

A  comparison  of  the  above  formulae  will  indicate  why  it  is  that 
glucose  and  fructose  yield  one  and  the  same  osazone. 

The  phenyl-hydrazones  are  also  utilized  in  the  formation  of  con- 
densed heterocyclic  compounds.  Thus  acetone  phenyl  hydrazone, 
CH3.C:N.NH.C0H5  CH3.C.NHv 

is  converted  into  a  methyl  indole  (p.  464),        II 

CH3  CH    ' 

C6H4,  by  loss  of  NH3. 

Acid  Derivatives  of  Phenylhydrazin. — A  great  number  of  com- 
pounds are  known,  formed  by  the  substitution  of  acid  radicals  for 


HYDEOAROMATIC    HYDROCARBONS  431 

the  amid  or  imid  hydrogen  of  phenylhydrazin.  These  compounds 
bear  the  same  relation  to  phenylhydrazin  that  the  anilids  bear  to 
anilin,  and  some  of  them  have  been  used  as  antipyretics,  e.  g., 
P  acetophenyl  -  hydrazid  —  Hydracetin  —  C6H5.NH.NH.CO.CH3  - 
formed  as  a  white,  crystalline,  tasteless,  and  odorless  powder,  spar- 
ingly soluble  in  water,  by  the  action  of  acetyl  chlorid  or  of  acetic 
anhydrid  upon  phenylhydrazin.  It  is  the  active  ingredient  of  an 
antipyretic  called  pyrodin. 


B.     HYDROAROMATIC   COMPOUNDS  WITH  A   SINGLE 

NUCLEUS. 

The  hydroaromatic  compounds  may  be  considered  as  derived  from 
the  benzenic  by  rupture  of  one  or  more  of  the  double  linkages  of  the 
benzene  ring  (p.  380),  by  which  the  valence  of  the  nucleus  is 
changed  from  six  to  eight,  ten  or  twelve. 

HYDROCARBONS. 

Hexahydrobenzenes  —  Cyclohexanes  —  Naphthenes.  —  These  com- 
pounds, of  which  hexahydrobenzene,  ^C^Qg^cHa/^2'  *s  ^e 
simplest,  and  the  parent  substance  of  the  hydroaromatic  compounds, 
exist  in  Russian  petroleum,  in  coal  tar,  and  in  "rosin  -oils."  They 
are  isomeric  with  the  olefins,  from  which  they  may  be  distinguished 
by  the  fact  that  they  do  not  combine  with  bromin. 

Tetrahydrobenzenes  —  Cyclohexenes  —  Naphthylenes  —  of  which 
the  lowest  term  is  tetrahydrobenzene,  H2C\Q^'c22^/CH,  exist  in 

rosin  -oils. 

Dihydrobenzenes  —  Cyclohexadienes  —  of  which  the  first  member 


x  PTT  \ 

is  dihydrobenzene,  RCGH'  .ciiCH,  probably  exist  in  many  of  the 


natural  products  called 

Terpenes.  —  Most  of  the  volatile,  or  essential  oils,  or  essences,  ob- 
tained by  distillation  of  various  plants  with  steam,  consist  of  hydro- 
carbons having  the  formula  CioHie,  and  most  of  the  camphors  and 
resins  are  alcoholic  or  ketonic  derivatives  of  these  hydrocarbons.  A 
few  of  the  essential  oils,  having  the  formula  CsHg,  are  known  as 
hemiterpenes,  or  olefin  terpenes,  and  are  unsaturated  aliphatic 
compounds  (p.  371).  Some  of  the  aromatic  terpenes  also  are  poly- 
meres,  having  the  formulae  x(C5H8).  Although  the  constitution  of 
the  aromatic  terpenes  is  not  completely  established,  they  are  hydro- 
aromatic  hydrocarbons  of  which  the  camphors  are  alcohols  or  ketones. 


432  MANUAL    OF    CHEMISTRY 

The  terpeocs  form  benzenic  compounds  by  oxidation.  With  the 
halogens  they  form  addition  products,  which  not  only  serve  for  their 
classification,  but  also  for  their  conversion  into  alcohol -camphors. 
With  nitrosyl  chlorid,  NOC1,  they  form  well-defined  nitroso-chlorids, 
as  dipentene  nitroso-chlorid,  CioHi6(NO)Cl,  which,  serve  for  their 
identification,  and  for  the  preparation  of  basic  and  other  derivatives. 

The  true  terpenes  and  their  derivatives  are  arranged  in  two 
classes:  (1)  The  Terpan  group,  and  (2)  the  Camphan  group. 

The  terpans  are  capable  of  taking  on  four  bromin  atoms,  and 
therefore  have  two  double  linkages.  It  is  assumed  that  in  them  the 
ten  carbon  atoms  are  arranged  in  a  hexacarbon  ring,  with  two  lateral 

23  9 

7     1/C~CX4      8,C 

chains  in  the  p-  position  to  each  other,  thus:    C— C<^        ^C— C<^  , 

C-C  C 

65  10 

aud  that  two  of  the  ten  bonds  are  double.  The  hydrocarbons  are, 
therefore,  dihydrocymenes  (p.  387).  The  carbon  atoms  are  num- 
bered as  above  to  indicate  the  positions  of  the  double  linkages,  which 
vary  in  the  different  isomeres.  The  positions  of  double  linkage  are 
marked  by  the  Greek  capital  A,  followed  by  the  numbers  of  the  carbon 
atoms  from  which  the  attachment  proceeds: 

Limonene— A(Ii8)Dihydrocymene— CHa.C^HsCH'/C^H-CxciEa- 
fprobably)  exists  in  three  optical  isomeres:  d-limonene ;  b.  p. 
175°  (347°  F.);  [a]D=  + 106.8°;  a  liquid  having  the  odor  of 
lemons,  existing  in  many  essential  oils,  such  as  those  of  orange, 
bergamot,  dill, etc.:  1-limonene;  b.  p.  175°  (347°  F.) ;  [a]D=  -105°; 
occurs  in  the  oils  of  peppermint,  fir  and  pine  needles.  [d+l]-limon- 
ene,  dipentene,  or  cinene;  b.  p.  175°  (347°  F.);  occurs  in  oil  of 
wormseed,  and  is  produced  by  the  action  of  a  heat  of  250°-300° 
upon  limonenes,  pinene  and  camphene,  and  therefore  exists  in  tur- 
pentine oil  produced  at  high  temperatures,  such  as  the  Russian  and 
Swedish.  The  limonenes  are  liquids  having  the  odor  of  lemons, 
and  combining  with  bromin  to  produce  solid  tetrabromids  having 
the  same  optical  action  as  the  parent  hydrocarbons. 

Other  terpans  are:  Terpinolene ;  f.  p.  75°;  formed  when  terpin 
hydrate,  terpineol,  or  cineol  is  heated  with  dilute  H2S04,  or  by  the 
action  of  the  concentrated  acid  on  pinene.  Sylvestrene ;  b.  p.  176°; 
[a]D= -f  66.32°;  occurs  in  Swedish  and  Russian  turpentine.  Ter- 
pinene;  b.  p.  180°;  is  formed  when  dipentene,  terpin,  phellandrene, 
terpineol  or  cineol  is  heated  for  some  time  with  dilute  alcoholic 
H2SO4,  or  by  the  action  of  the  concentrated  acid  on  pinene,  or  by 
the  action  of  formic  acid  on  linalool  (p.  372).  It  is  not  converted 
into  other  terpans  by  acids,  and  does  not  yield  a  bromin  derivative, 


HYDROAEOMATIC    HYDROCARBONS  433 

but  forms  a  nitroso-chlorid.  Phellandrene  ;  b.  p.  170°;  exists  in  el- 
and 1-  modifications.  It  has  the  same  negative  qualities  as  ter- 
pinene.  Menthene,  CioHig,  is  a  hydro  terpan,  formed  by  acting  upon 
potassium  phenate  with  menthyl  chlorid;  b.p.  167°. 

The  members  of  the  camphan  group  are  capable  of  taking  up 
two  bromin  atoms,  and  are  considered  as  probably  containing  a 

CH3 
dihydrobenzene   ring   with   a  —  C-     group   linking   the   p-positions 

CHa 

internally,  as  in  the  probable  formula  of 

/CH2  —  CH2\ 

Camphene  —  CH3—  C-(CH3.C.CH3)-CH—  which  is  a  solid;   f.  p. 
\CH  =  CH  / 

43°  (109.4°  F.);  b.p.  160°  (320°  F.);  nD  =  1.45514  (54°);  (p.  21); 
known  in  d-,  1-,  and  [d+1]  modifications.  It  exists  in  Ceylon 
citronella  oil,  and  is  produced  by  the  action  of  dehydrating  agents 
upon  its  alcohol,  Borneo  -camphor  (p.  435).  It  forms  a  dibromid. 

Pinene  —  CioHie  —  is  the  principal  constituent  of  oil,  or  essence 
of  turpentine,  and  exists  also  in  many  other  essential  oils.  It  is  a 
colorless  liquid;  b.  p.  155°  (311°  F.);  sp.  gr.  0.858  (20°);  nD  = 
1.46553  (21°).  It  exists  in  three  optical  isomeres  :  d-pinene; 
[a]D  =  r7°;  predominates  in  American  oil  of  turpentine;  1-pinene; 
MD  =  —  40.3°;  in  the  French  oil.  Pinene  combines  with  bromin  to 
form  a  dibromid:  it,  therefore,  contains  one  double  linkage.  When 
dry  HC1  gas  is  passed  through  pinene,  well  cooled,  a  white,  crys- 
talline substance,  fusing  at  125°  (257°  F.),  and  having  the  odor  of 
camphor,  separates.  This  is  d-pinene  hydrochlorid,  CioHrrCl,  or 
"artificial  camphor." 

Turpentine  is  a  yellowish  -white,  semi-solid  substance,  having  a 
balsamic  odor,  which  exudes  from  incisions  in  the  bark  of  Pinus 
palustris,  P.  tceda,  and  other  Coniferce,  and  which  may  be  taken  as 
the  type  of  a  number  of  other  similar  products.  These  substances, 
when  distilled  with  steam,  yield  two  products,  one  a  solid,  yellow  or 
brown  residue,  a  stearoptene,  such  as  rosin  or  colophany;  the  other 
a  volatile,  oily  liquid,  an  eleoptene,  such  as  oil,  or  essence,  of  tur- 
pentine. Oil  of  turpentine  is  insoluble  in  water,  mixes  with  alcohol 
and  with  ether,  and  dissolves  phosphorus,  sulfur  and  caoutchouc. 
When  exposed  to  the  air  it  is  oxidized  to  gummy,  aldehydal  products, 
which  finally  harden,  hence  its  use  as  a  drier  in  the  manufacture 
of  paints  and  varnishes.  On  contact  with  HNOs,  its  oxidation  is 
so  violent  as  to  cause  ignition.  H2S04  also  acts  upon  it  energetically, 
with  formation  of  a  number  of  polymeres. 

Hydroterpenes  are  naphthenes  (p.  431)  obtained  by  decomposi- 
tion of  certain  natural  alcohol  -camphors.  Thus  hexahydrocymene, 

is  derived  from  menthol  (D.  435). 


28 


434  MANUAL    OF    CHEMISTRY 

HYDROAROMATIC    ALCOHOLS. 

The  hydroaromatic  alcohols  are,  for  the  most  part,  "ring  alco- 
hols," and  contain  either  CHOH  or  COH,  as  a  part  of  the  ring, 
although  in  some,  as  in  some  of  the  terpan  alcohols  (below),  the 
alcoholic  group,  which  may  then  also  be  ClbOH,  is  contained  in  the 
lateral  chain.  These  alcohols  may  be  obtained  by  reduction  of  the 
corresponding  ketones  (p.  436),  or  of  other  aromatic  or  hydroaromatic 
compounds.  Several  of  them,  such  as  quercite,  inosite  and  some  of 
the  camphors,  are  natural  products. 

Q  u  i  n  i  t  e  —  HOHC  ^cH^cIl/  CHOH  ~  and    phloroglucite  - 
-~are    reduction   products   of    the  phenols, 


quinol,  HOC^i;£JH^C!OH,   and   phloroglucin, 
respectively  (p.  394). 

Quercite  —  H2C<^HOH:cHOH/CHOH  —  a  pentatomic  alcohol,  ob- 
tained from  acorns.  It  is  a  sugar  -like  substance,  but  is  not  affected 
by  alkalies,  does  not  ferment,  and  does  not  reduce  Fehling's  solution. 
F.p.  235°;  [a]D=  +24.16°. 

Inosite  —  CeHsCOHje  —  metameric,  though  not  related,  to  the 
glucoses,  is  a  hexatomic  alcohol,  in  which  probably  two  hydroxyls 
are  attached  to  the  same  carbon  atom,  as  it  exists  in  three  optical 
modifications.  The  inactive  modification  exists  in  the  liquid  of 
muscular  tissue,  in  the  lungs,  kidneys,  liver,  spleen,  brain  and  blood; 
in  traces  in  normal  urine,  and  increased  in  Bright's  disease,  in  dia- 
betes, and  after  the  use  of  drastics  in  uraemia;  in  the  contents  of 
hydatid  cysts;  in  beans  and  peas,  and  in  certain  other  seeds  and 
leaves.  It  crystallizes  in  needles,  usually  arranged  in  cauliflower  -like 
masses,  has  a  sweet  taste,  is  readily  soluble  in  water,  sparingly  soluble 
in  alcohol,  insoluble  in  absolute  alcohol  and  in  ether.  It  does  not 
ferment,  is  not  colored  by  alkalies,  and  does  not  reduce  Fehling's 
solution.  When  heated  to  170°  (338°  F.)  with  HI,  it  is  decomposed 
into  phenol,  diiodophenol  and  benzene.  When  treated  with  HNOs, 
evaporated  to  near  dryness,  the  residue  moistened  with  NHtHO  and 
CaCU,  and  again  evaporated,  a  rose  -red  residue  is  left  (Scherer's 
reaction).  Mercuric  nitrate  produces  in  solutions  of  inosite  a  yellow 
precipitate,  which,  on  cautious  heating,  turns  red.  The  color  dis- 
appears on  cooling  and  reappears  on  heating  (Gallois7  reaction). 

Dambonite,  a  supposed  glucosid  (p.  409)  obtained  from  an 
African  caoutchouc,  is  the  dimethyl  ether  of  i-inosite  (dambose). 

The   terpan   alcohols    are   derivatives   of   hexahydrocymene,  or 

menthan  (p.  433),  H3C.CH<^cl';cH22/CH-CH\CH3'  or  Ci0H20;  or  of 
menthene,  CioHis;  or  of  menthadiene,  CioHie;  differing  from  menthan 


HYDEOAKOMATIC   ALCOHOLS  435 

by  the  introduction  of  one  and  two  double  bonds  respectively.  They 
are  monacid,  diacid,  etc.,  according  to  the  number  of  hydroxyls  sub- 
stituted for  hydrogen.  Among  them  are  menthol  and  terpin  and  its 
hydrate. 

Menthol  —  Oxyhexahydrocymene  — 

/  c\  FT 

CH<^CH^  —  is  a  monacid  menthan  alcohol.     It  is  the  chief  constituent 

of  oil  of  peppermint.  It  crystallizes  in  prisms,  fusible  at  42°  (107.6° 
F.),  sparingly  soluble  in  water,  readily  soluble  in  alcohol,  ether 
and  carbon  disulfid,  and  in  acids.  Corresponding  to  it  are  a  series  of 
menthyl  esters. 

Terpins. — There  are  two  diacid  menthan  alcohols,  in  which  the 
hydroxyls  occupy  the  1,8  positions  (p.  432).  The  formula  of  cis- 
terpin,  the  parent  substance  of  terpin  hydrate  and  of  cineol,  is 

HaCv        xCHg.CHjv        /IS. 
now   considered   as    being          /C\  /C\    /OH         while    in 

HO/    \CH2.CH2/     XC=(CH3)2 

trans-terpin  the  positions  of  the  CHs  and  OH  attached  to  C(l)  are 
reversed.  Cis-terpin  is  obtained  by  dehydration  of  terpin  hydrate, 
and  also  from  [d+l]-limonene  dihydrochlorid  (p.  432).  It  is  crys- 
talline, fuses  at  104°  (219.2°  F.),  and  boils  at  258°  (496.4°  F.). 
It  absorbs  water  eagerly  to  form  terpin  hydrate.  Gaseous  HC1,  or 
PCls,  converts  it  into  [d+l]-limonene  hydrochlorid. 

Terpin  Hydrate  —  CioHw( OH) 2  +  EbO  —  is  formed  when  oil  of 
turpentine  remains  long  in  contact  with  water,  more  rapidly  in 
presence  of  alcohol  and  dilute  HNOs;  also,  similarly,  from  pinene 
and  from  limonene.  It  forms  rhombic  crystals,  fusible  at  117° 
(242.6°  F.),  with  loss  of  EbO  and  conversion,  slowly,  into  terpin. 
It  is  easily  soluble  in  alcohol,  sparingly  soluble  in  water,  chloroform 
and  ether.  It  is  used  as  an  expectorant. 

Cineol  —  Eucalyptol  —  CioHie(OH)2  —  another  diacid  menthan  al- 
cohol, is  obtained  from  the  leaves  of  Eucalyptus  globulus,  and  also 
exists  in  wormseed  oil  (Oleum  cince)  and  in  other  volatile  oils.  It  is 
a  colorless  oil,  having  a  camphor-like  odor;  sp.  gr.  0.93  at  15°; 
b.  p.  176°;  nD  =  1.4559;  soluble  in  alcohol,  sparingly  soluble  in 
water.  Dry  HC1  gas  passed  through  its  petroleum  ether  solution 
separates  white  scales  of  eucalypteol,  CioHi6.2HCl,  which  is  decom- 
posed by  water  with  regeneration  of  cineol. 

Terpineols  are  monacid  menthene  alcohols.  The  A1?  (OH)(8)  ter- 
pineol  is  formed  by  removal  of  2H2O  from  terpin  hydrate.  It  is  a 
solid;  f.  p.  35°  (95°  F.).  When  boiled  with  dilute  acids  it  forms 
carvacrol  (p.  392),  and  the  ketone,  carvone  (p.  436).  It  forms  dipen- 
tene  when  heated  with  KHSO4. 

Borneol  —  Camphol  —  Borneo  Camphor — CioHigO  —  a  monacid 
alcohol,  is  the  best  known  of  the  camphan  alcohols.  It  exists  in 


436  MANUAL    OF    CHEMISTRY 

three  optical  modifications;  the  d-borneol  being  the  one  usually  met 
with,  and  obtained  from  Dryobalanops  camphora.  The  d-  and  1- 
modifications  are  both  formed  by  hydrogenation  of  laurel  camphor. 
It  forms  small,  friable  crystals;  has  an  odor  recalling  those  of  laurel 
camphor  and  of  pepper,  and  a  hot  taste ;  is  insoluble  in  water,  readily 
soluble  in  alcohol,  ether,  and  acetic  acid;  fuses  at  203°  (397.4°  F.); 
boils  at  212°  (413.6°  F.) .  It  is  oxidized  to  laurel  camphor  by  HNO3. 
Heated  with  KHSO*,  it  is  decomposed  into  camphene  (p.  433)  and 
H20. 

HYDROAROMATIC  KETONES  AND  ACIDS. 

The  hydroaromatic  ketones  are  "ring  ketones,"  the  CO  group 
forming  a  part  of  the  ring.  They  are  formed:  (1)  by  reduction  of 
the  corresponding  aromatic  phenols;  (2)  by  oxidation  of  the  secon- 
dary ring -alcohols;  (3)  by  condensation  of  the  esters  of  the  aliphatic 
ketone  acids  (p.  298),  or  of  the  ketones.  The  terpan  and  camphan 
ketones  exist  in  nature.  The  ketones  form  ketoxims  with  hydroxyl- 
amin  (p.  361),  and  hydrazones  with  phenyl  hydrazin  (p.  429),  which 
serve  for  their  identification. 

Pimelin-ketone— CH2<(cHo2;cH2/>"~CO~~is  the  simplest  of  the  hy- 
droaromatic ketones.  It  is  an  oil,  having  the  odor  of  peppermint;  b. 
p.  155°  ;  formed  by  electrolytic  reduction  of  phenol;  by  oxidation  of 

hexahydrophenol,  CH^H^n'/CHOH;  or  bv  distillation  of  cal- 
cium pimelate,  CH2<(cH2:cH':co22/Ca  <P-  289)-  Its  oxim  fuses  at  88°- 

The  terpan  ketones,  or  ketohydro-p-cymenes,  are  formed  by 
oxidation  of  the  corresponding  secondary  alcohols  (p.  435). 

Menthone — CioHisO — (CO-3) — is  a  ketomenthan,  existing  in  oil 
of  peppermint.  It  is  known  in  two  optical  isomeres  :  1-menthone  is 
formed  by  oxidizing  menthol,  and  is  converted  into  d-menthone  by 
contact  with  H2SO4.  B.  p.  206°  ;  [a]D=  —28°  and  +28°.  1-Men- 
thoxim  fuses  at  59°. 

Thujone — Tanacetone — and  Pulegone — CioHieO,  are  ketomen- 
thenes,  the  former,  b.  p.  200°,  existing  in  tansy  and  thuja  oils;  the 
latter,  b.  p.  221°,  in  "polei-oils." 

Carvone — Carvol — CioHuO — is  a  ketomenthadiene,  known  in 
three  optical  isomeres,  which  boil  at  225°.  d-Carvol  exists  in  cumin 
and  dill  oils;  [a]o=H-62°.  Heated  with  KHO,  it  is  converted  into 
its  isomere  carvacrol  (p.  392).  The  three  carvoxims  are  formed 
either  by  the  action  of  hydroxylarnin  upon  the  corresponding  car- 
vones,  or  by  the  action  of  boiling  KHO  upon  the  three  limonene 
nitrosochlorids  (p.  432). 

d-Camphor — Common  camphor — Laurel  camphor — Japan  cam- 


HYDKOAROMATIC    KETONES    AND    ACIDS  437 

phor — CioHieO — is  the  most  important  of  the  camphan  ketones.  It 
is  obtained  from  the  camphor  tree  (Laurus  campliora) ,  and  is  formed 
artificially  by  oxidation  of  borneol  or  of  camphene.  It  forms  trans- 
lucent, friable  crystals;  hot  and  bitter  in  taste,  aromatic;  sparingly 
soluble  in  water,  quite  soluble  in  acetic  acid,  methylic  and  ethylic 
alcohols,  and  the  oils;  f.  p.  175°  (347°  P.);  b.  p.  204°  (399.2°  P.); 
sp.  gr.- 0.985;  sublimes  at  all  temperatures;  [a]D=  +44.22. 

It  ignites  readily,  and  burns  with  a  luminous  flame.  Cold  HNOs 
dissolves  it,  and  H^O  precipitates  it  unchanged  from  the  solution. 
Hot  HNOs,  or  potassium  permanganate,  oxidizes  it  to  d-camphoric 
acid.  Distilled  with  P2Os  it  yields  cymene,  CioHu.  Reducing  agents 
convert  it  into  borneol.  Heated  with  iodin,  it  is  converted  into  car- 
vacrol  (p.  392).  Bromin  unites  with  it  to  form  ruby -red  crystals  of 
an  unstable  compound,  CioHuOB^,  which,  when  heated,  fuse  and 
give  off  HBr,  leaving  an  amber -colored  residue,  which,  on  recrystal- 
lization  from  boiling  alcohol,  leaves  long,  hard,  rectangular  crystals 
of  monobromo-camphor,  CioHisOBr;  f.  p.  76°;  soluble  in  alcohol 
and  in  ether. 

1-Camphor  is  obtained  from  the  oil  of  Matricaria  postlanlum; 
MD=  — 44.22°.  [d -f- 1] -Camphor  exists  in  the  essential  oils  of 
rosemary,  sage,  lavender  and  origanum,  or  is  formed  by  mixing  el- 
and 1-  camphors,  or  by  oxidation  of  [d+1] -borneol,  or  of  [d+1]- 
camphene.  F.  p.  179°. 

Hydroaromatic  Carboxylic  Acids. — A  great  number  of  these 
acids  are  known,  some  pure  acids,  others  oxy-  or  ketonic  acids,  con- 
taining from  one  to  six  carboxyl  groups,  and  hexahydro-,  tetrahydro- 
and  dihydro-.  The  most  important  are: 

Quinic  Acid  —  Hexahydro-tetraoxybenzoic  Acid  —  CeH7(OH)4.- 
COOH  —  which  exists,  combined  with  the  alkaloids,  in  cinchona 
barks,  also  in  coffee  beans  and  in  other  plants.  It  forms  hard, 
transparent  prisms,  soluble  in  water  and  in  alcohol;  fuses  at  160°; 
lasvogyrous.  On  distillation,  it  yields  phenol,  hydroquinol,  benzole 
acid  and  salicylic  aldehyde.  Hydriodic  acid  reduces  it  to  benzole  acid. 

Terebic  Acid  — C7H10O4— f.  p.  175°;  and  Terpenylic  Acid- 
C8Hi2O4  —  f.  p.  90°,  are  oxidation  products  of  oil  of  turpentine, 
obtained,  the  former  with  HNOs,  the  latter  with  chromic  acid  mixture. 

Camphoric  Acids— C8Hi4(COOH)2.— The  d-,  1-,  and  [d+l]-acids 
are  known.  d-Camphoric  acid  is  produced  by  oxidizing  common 
d-camphor  by  heating  with  HNOs.  It  forms  colorless,  odorless 
needles,  soluble  in  alcohol,  ether  and  boiling  water;  f.  p.  187°; 
MD=  +49.7°.  By  further  oxidation  it  yields  camphoronic  acid, 
or  trimethyl-tricarballylic  acid  (p.  289). 

Resins  —  are  generally  the  products  of  oxidation  of  the  hydro- 
carbons allied  to  pinene;  are  amorphous  (rarely  crystalline);  insol- 


438 


MANUAL    OF    CHEMISTRY 


uble  in  water;   soluble  in  alcohol,  ether,  and  essences.     Many  of  them 
contain  acids. 

They  may  be  divided  into  several  groups,  according  to  the  nature 
of  their  constituents:  (1)  Balsams,  which  are  usually  soft  or  liquid, 
and  are  distinguished  by  containing  free  cinnamic  or  benzoic  acid 
(q.v.).  The  principal  members  of  this  group  are  benzoin,  liquid- 
ambar,  Peru  balsam,  styrax,  and  balsam  tolu;  (2)  oleo-resins  consist 
of  a  true  resin  mixed  with  an  oil,  and  usually  with  an  oxidized 
product  other  than  cinnamic  or  benzoic  acid.  The  principal  members 
of  this  group  are  Burgundy  and  Canada  pitch,  Mecca  balsam,  and 
the  resins  of  capsicum,  copaiva,  cubebs,  elemi,  labdanum,  and  lupulin; 
(3)  gum-resins  are  mixtures  of  true  resins  and  gums.  Many  of 
them  are  possessed  of  medicinal  qualities:  aloes,  ammoniac,  asafoetida, 
bdellium,  euphorbium,  galbanum,  gamboge,  guaiac,  myrrh,  olibanum, 
opoponax,  and  scammony;  (4)  true  resins  are  hard  substances  ob- 
tainable from  the  members  of  the  three  previous  classes,  and  contain- 
ing neither  essences,  gums,  nor  aromatic  acids.  Such  are  colophony 
or  rosin,  copal,  dammar,  dragon's  blood,  jalap,  lac,  mastic,  and  san- 
darac;  (5)  fossil  resins,  such  as  amber,  asphalt,  and  ozocerite. 


C.  COMPOUNDS  WITH  CONDENSED  NUCLEI. 

These  compounds  contain  two  or  more  benzene  rings,  or  one  or 
more  benzene  rings  and  a  pentacarbocyclic  ring,  fused  together  in 
such  manner  that  the  adjacent  rings  have  two  carbon  atoms  in  com- 
mon. The  parent  hydrocarbons  of  these  compounds  are  :  indene, 
fluorene,  naphthalene,  anthracene,  phenanthrene,  chrysene,  and 
picene  : 


HC 


H 

H 

H 

H 

H 

C 

C 

C 

C 

C 

'  \                               ^ 

'  \ 

/  ^                        / 

^  N 

\  / 

'  % 

C  CH 

HC 

c- 

C          CH             HC 

C 

CH 

II 
C 

II 
CH 

Hi 

II 
c 

II           1                     1 
C          CH             HC 

1! 
c 

L 

>  /  \  /                  \  /   N 

\/  \  / 

^  / 

'  \ 

\  ^ 

C 

C 

c 

C         C 

C 

C 

H 

H2 

H 

H2       H 

H 

H 

Indene. 

Fluorene. 

Naphthalene. 

H          H          H 

H  H 

H 

H 

C          C          C 

C=C 

C=C 

/: 

^  \    / 

\  / 

% 

/         \          /         \ 

HC 

C 

c 

CH 

HC                C-C 

CH 

HC 

II 
C 

II 
c 

(L 

\        #         \         # 

C—  C                C-C 

\  /    \ 

/  \  . 

/ 

Hv 
\ 

/ 

H 

C          C          C 

c=c 

H         H         H 

H   H 

Anthracene. 

Phenanthrene. 

CONDENSED  HYDROCARBONS  439 

The  derivatives  of  these  hydrocarbons  are  similar  in  their  general 
properties  to  the  benzene  derivatives,  with  some  differences  in  orien- 
tation. Chrysene,  CisHi2,  and  picene,  C22Hi4,  are  naphthalene-phen- 
anthrenes  (p.  441).  Most  of  these  hydrocarbons  form  crystalline 
addition  products  with  picric  acid. 


CONDENSED   HYDROCARBONS. 

These  hydrocarbons  accompany  benzene  in  coal-tar.  Naphtha- 
lene and  anthracene  are  obtained  from  this  source  industrially. 

Indene  —  CgHs  —  (constitution,  p.  438)  —  exists  in  the  fraction  of 
coal-tar,  distilling-  between  176°  and  182°.  It  has  also  been  obtained 
synthetically.  Indene  derivatives  can  also  be  produced  from  naph- 
thalene derivatives,  one  benzene  ring  being  converted  into  a  penta- 
carbocyclic  ring  (see  formula?,  p.  438).  Indene  is  the  hydrocarbon 
corresponding  to  indole,  which  contains  NH  in  place  of  the  CH2 
group  (p.  463).  It  is  an  oil;  b.  p.  178°;  sp.  gr.  1.04  at  15°.  At  a  red 
heat  two  molecules  of  indene  unite,  with  loss  of  4H,  to  form  chrysene 
(p.  441).  By  reduction  indene  is  converted  into  hydrindene,  CeHi: 
(CH2)3;  an  oil;  b.  p.  177°. 

Fluorene  —  Diphenylene  Methane  —  CiaHio  —  exists  in  the  frac- 
tion of  distillation  of  heavy  coal-tar  oils,  distilling  between  300° 
and  320°.  It  is  also  formed  by  the  action  of  red  heat  upon  diphenyl 
methane  (CeHshCH^,  and  from  other  diphenyl  and  phenanthrene 
derivatives.  It  crystallizes  in  colorless  leaflets,  having  a  violet  fluor- 
escence; f.  p.  113°;  b.  p.  295°;  very  soluble  in  ether  and  in  benzene, 
sparingly  soluble  in  alcohol.  Its  picric  acid  compound  forms  red 
needles,  f.  p.  81°. 

The  constitutional  formula  of  fluorene  is  given  on  p.  438.  It  may 
be  considered  as  formed  by  fusion  of  two  benzene  rings  and  one 
pentacarbocyclic  ring,  with  absorption,  consequently,  of  all  but  one 
of  the  carbon  atoms  of  the  latter.  Or  it  may  be  considered  as 
diphenylene  methane,  i.  e.,  methane  in  which  2H  are  replaced  by  two 


phenylene    groups,    externally   united:  /CH.2.      It    is,    indeed, 

CoHv 

closely  related  to  other  diphenylene  compounds,  in  which  the  CH2 
group  is  replaced  by  other  bivalents,  as  by  O,  S,  and  NH,  in  di- 
phenylene oxid,  sulfid  and  imid  (carbazole,  p.  467).  Other  fluorene 
derivatives  are  also  known  containing  both  diphenylene  and  diphenyl 
(p.  446)  groups,  or  two  diphenylenes,  as  diphenylene-diphenyl- 
ethylene,  (C6H4)2C:C(C6H5)2,  and  bidiphenylene  ethane,  (C6H4)2- 
CH.CH(C6H4)2. 

Naphthalene  —  CioHs  —  is  obtained  commercially  from  the  fraction 


440  MANUAL    OP    CHEMISTRY 

of  coal-tar  distillation  passing  between  180°  and  300°.  It  crystallizes 
in  shining  plates;  f.  p.  79°;  b.p.  218°;  volatile  at  all  temperatures, 
giving  off  a  peculiar,  tarry  odor  (white  tar,  moth-balls);  sparingly 
soluble  in  cold  alcohol,  readily  soluble  in  hot  alcohol,  ether  and 
benzene.  It  is  used  in  the  arts  in  the  preparation  of  phthalic  acid 
and  its  derivatives,  of  the  naphthols,  etc.,  and  of  a  great  number  of 
naphthalene  dyes,  for  the  carburation  of  water-gas,  and  against 
moths.  Its  picric  acid  compound  fuses  at  149°. 

Naphthalene  is  undoubtedly  formed  in  the  distillation  of  coal  by 
condensation  of  lower  hydrocarbons  under  the  influence  of  heat,  a 
formation  which  may  be  imitated  by  conducting  a  mixture  of  benzene 
vapor  with  acetylene,  or  with  ethylene,  through  a  tube  heated  to 
redness.  With  ethylene,  cinnamene  (p.  387)  is  formed  as  an  inter- 
mediate product.  Naphthalene  derivatives  are  also  formed  by  con- 
densation of  several  monobenzenic  derivatives  with  unsaturated  lateral 
chains.  Thus  anaphthol  is  produced  from  phenyl-isocrotonic  acid: 

,CK  =  CH  /CH  =  CH 

Coils'  I     =C6H4<r  I    +H20;    and   naphthalene   itself   is 

HOOC.CH2  XC(OH):CH 

formed   when   phenylbutylene   vapor   is    passed   over   heated    lime: 

/CH=CH 

C6H5.CH2.CH2.CH:CH2  =  C6H4  I      +  2H2.      Oxidizing   agents 

X\CH=CH 

convert  naphthalene  into  naphthoquinones  (p.  444),  and  into  benzene- 
carboxylic  acids,  among  others  into  phthalic  acid,  CeH^COOHh. 
Sulfuric  acid  forms  with  it  sulfonic  acids. 

Naphthalene  Homologues  —  formed  by  substitution  of  alkyls  for 
hydrogen,  exist  in  coal-tar,  and  are  formed  by  the  action  of  alkyl 
iodids  or  bromids  upon  naphthalene  in  presence  of  A^Cle. 

Acenaphthene  —  1,  8  —  (or  peri-,  p.  442)  Ethylene  naphthylene, 


, 
CioHe:C  I        ,  is  formed  when  a  ethyl-naphthalene  is  passed  through 

N  CH2(8) 

a  red-hot  tube,  and  also  exists  in  coal-tar.  By  oxidation,  nitration, 
etc.,  it  yields  a  series  of  peri  -naphthalene  derivatives. 

Hydronaphthalenes  and  their  substitution  products  are  derived 
from  naphthalene  by  rupture  of  one  or  more  of  the  double  bonds, 
in  the  same  manner  as  the  hydroaromatic  compounds  are  derived 
from  benzene  (pp.  443,  431). 

Anthracene  —  CuHio  —  is  obtained  commercially  from  the  "green 
oil"  of  coal-tar,  distilling  above  270°;  and  is  used  in  the  manufac- 
ture of  alizarin  dyes  (artificial  madder).  It  is  formed  from  benzene 
and  acetylene,  or  methylene  bromid,  in  presence  of  A^Cle.  It  crys- 
tallizes in  colorless  plates,  having  a  fine  blue  fluorescence;  f.  p.  213°; 
b.p.  351°;  sparingly  soluble  in  benzene  and  in  carbon  disulfid,  which 
are  its  best  solvents.  Oxidizing  agents  convert  it  into  anthraquinone. 
Its  picric  acid  compound  forms  red  needles,  f.  p.  138°. 


HALOID    DERIVATIVES  — ORIENTATION  441 

The  constitution  of  anthracene,  given  on  p.  438,  is  proven  by 
the  formation  of  anthraquinone,  which  is  diphenylene  diketone  : 
CeELi:  (CO)2:CeH4,  in  which  the  internal  bond  is  liberated. 

Phenanthrene  —  CioHu —  isomeric,  with  anthracene,  accompanies 
that  hydrocarbon  in  coal-tar.  It  is  also  formed  by  condensation  of 
many  benzene  compounds  when  their  vapor  is  passed  through  a 
red -hot  tube.  It  crystallizes  in  colorless  plates;  f.  p.  99°;  b.  p  340°; 
sublimes  readily  at  lower  temperatures;  soluble  in  benzene,  ether 
and  hot  alcohol,  the  solutions  having  blue  fluorescence.  Oxidizing 
agents  convert  it  into  phenanthroquinone  (p.  444).  Its  picric  acid 
compound  forms  yellow  needles,  f .  p.  144°. 

Phenanthrene  is  closely  related  to  fluorene  (p.  439) ,  and  to  diphenyl 

(p.  446) .  It  is  considered  as  diphenyl,  HC^cH.'cH/p-^cllcH^011' 
in  which  the  two  ortho  positions  (o)  are  united  by  the  group  — CH: 
CH — ,  while  fluorene  is  diphenyl  in  which  the  same  positions  are 
united  by  the  group  — CH — . 

C6H4  — CH 
Chrysene-l  II     —  f.  p.    250°;    b.  p.    448°  —  and  Picene  — 

CloHe — CH 
CioHG— CH 

II    — f.  p.  364°;  resemble  phenanthrene  in  structure,  except 
CioHo — CH 

that  they  contain  one  and  two  double  naphthalene  rings  respectively 
in  place  of  benzene  nuclei.  They  exist  in  the  coal-tar  residues. 


HALOID    DERIVATIVES  —  ORIENTATION. 

The  complex  character  of  the  nuclei  in  these  hydrocarbons  indi- 
cates the  possible  existence  of  a  greater  number  of  isomeres  than 
are  met  with  in  the  monobenzenic  series. 

With  indene  different  products  are  obtained  by  substitution  in 
the  benzene  ring  and  in  the  three  pentol  positions.  The  former  are 
designated  by  the  abbreviations  Bz,  the  latter  by  the  Greek  letters 
a,  /?,  y.  Thus  Bz-brom-  indene: 

Br  H  COOH  H         Cl 

C  C  C  Ca        Ca 

^  8\   /l\ 
HC2          C  -  CH  HC          C  -  C          CH          /3HC7          C          2CH/3 


I      Bz    ||             ||  I            II             II           I  I             II 

HC3           C            CH  HC           C             C          CH  /3HC6           C          3CC1/3 

\4/    \7//3  /3\a/\     /    \«/-/3  \5/    \4^ 

C            C  C            C             C  Ca        Ca 

H          H2  H        7H2          H  H          H 

Bz  -Brom-indene.  a-Pluorenic  acid.  1,  3-Dichlornaphthalene. 

Bi-  substituted  derivatives  are  o-,  m-,  and  p-  in  the  benzene  ring, 
and  «,  /3,  y  in  the  pentol  ring.  Several  chlorindones  are  known,  up 
to  perchlorindone  : 


442  MANUAL    OF    CHEMISTRY 

There  are  three  distinct  positions  of  monosubstitution  in  the 
fluorene  nucleus:  (1)  the  four  positions  in  the  benzene  rings  nearest 
to  the  pentol  ring,  designated  as  a  ;  (2)  the  four  positions  furthest 
removed  therefrom,  designated  as  /?,  and  (3)  the  single  position  in  the 
pentol  ring,  designated  as  7.  A  dibromid  and  a  tribromid  are  known. 

The  naphthalene  haloids  and  other  products  of  substitution  have 
been  better  studied.  There  are  two  positions  of  monosubstitution, 
the  four  a  positions  nearest  to  the  fusion  of  the  two  rings,  and  the 
four/8  positions,  furthest  removed  therefrom.  Both  a  and  /?  fluorids, 
chlorids,  bromids,  and  iodids  are  known.  There  are  ten  possible  iso- 
meres  of  each  bisubstituted  derivative.  These  are  distinguished  by 
using  the  numerals  attached  to  the  several  positions  as  given  above, 
or  by  the  use  of  prefixes,  as  follows  :  1,  2-ortho,  1,  3-meta,  1,  4- 
para,  1,  5-ana,  1,  6-epi,  1,  7-kata,  1,  8-peri,  2,  3-allortho,  2, 
6-amphi,  2,  7-pros.  The  ten  possible  dichlorids  are  known.  In  all 
there  are  75  possible  naphthalene  chlorids,  of  which  26  are  known, 
and  as  many  bromids,  etc. 

In  anthracene  there  are  three  positions  of  monosubstitution:  the 
four  «  positions  nearest  to  the  uniting  groups  in  the  benzene  rings; 
the  four  /?  positions  furthest  removed  therefrom;  and  the  two  y,  or 
"meso"  (  =ms.),  positions  in  the  uniting  groups  (see  below).  The 

in 


y  mono-   and   di-chlorin    and    broinin    compounds   are   formed 
preference. 

H            CH3       H                                 H    H               H    H 
a  C              C     7      C  a                          Wi  C=C  (h          o  C=Cm 
/8\/m    s.\/l\                           /         \          /         \ 

/SHC7          C 

C       2CH  /3 

HC                C—  C                CH 

1             II 
/3HC6          C 

C       3CH  0 

Pl  \         -/         \         -/  P 
C—  C                C—  C 

\,5  X\TH 

8.  /\4^ 

Ha    \           /Ha 

a  C              C       7     C  a 

c=c 

H             CH3       H 

H0     0COOH 

ms.  (or  7)  Dimethyl  anthracene. 

/3-Phenanthrene  carboxylic  acid. 

In  phenanthrene  there  are  five  positions  of  monosubstitution  : 
one  in  each  of  the  o-,  01-,  m-,  mi-,  p-,  and  pi-  positions  of  the 
diphenyl  (p.  446),  the  two  remaining  m-positions  of  the  diphenyl, 
designated  as  <*f  and  the  two  positions  in  the  connecting  group, 
-C:C-,  designated  as  /3.  Chlorids  are  known  as  high  as  the  octo- 
chlorid,  and  bromids  as  high  as  the  heptabromid. 


PHENOLS,  ALCOHOLS,  ALDEHYDES,  KETONES,  QUINONES, 
CARBOXYLIC  ACIDS. 

The  phenols,  particularly  those  of  naphthalene,  the  oxynaph- 
thalenes,  or  naphthols,  are  the  most  important  of  those  compounds. 
The  naphthols  exist  in  coal-tar,  and  are  also  manufactured  syntheti- 


PHENOLS,    ALCOHOLS,   ALDEHYDES,    ETC.  443 

cally  by  the  methods  indicated  below.  They  readily  form  ethers,  and 
with  ammonia  they  produce  the  corresponding  naphthylamins.  Both 
naphthols  are  used  medicinally  as  antiseptics. 

a-Naphthol  —  CioH7.(OH)« — is  obtained  by  heating  phenyl- 
isocrotonic  acid  (p.  440) ;  also  by  boiling  an  aqueous  solution  of 
diazonaphthalene  nitrate  with  nitrous  acid,  or  by  fusing  a-naphtha- 
lene-sulfonic  acid  with  KHO. 

It  crystallizes  in  colorless  prisms;  f.  p.  95°  (203°  F.);  b.  p.  280° 
(536°  F.) ;  nearly  insoluble  in  water,  soluble  in  alcohol  and  in  ether; 
is  easily  volatile,  and  has  the  odor  of  phenol.  It  gives  a  transient 
violet  color  with  Fe2Cle  and  a  hypochlorite.  With  nitrous  acid  it 
forms  2,  1  and  4,  1  nitroso-naphthols.  Potassium  chlorate  and  hy- 
drochloric acid  oxidize  it  to  dichloro-naphthoquinone.  Nascent 
hydrogen  (sodium  and  alcohol)  reduce  it  to  ar-tetrahydronaphthol 
(below).  Its  acetate  fuses  at  46°  (114.8°  F.). 

/3- Naphthol — CioEWOH)/? — is  prepared  industrially  by  fusion  of 
sodium  ft- naphthalene -sulfonates  with  NaHO,  for  use  in  the  manu- 
facture of  a  number  of  dyes,  among  which  are  Campobello  yellow 
and  the  tropeolins.  It  crystallizes  in  colorless,  silky  plates,  which 
turn  dark  in  daylight;  has  a  faint  phenol -like  odor,  and  a  sharp, 
burning  taste  ;  f.  p.  123°  (253.4°  F.);  b.  p.  286°  (514. 8°  F.);  spar- 
ingly soluble  in  water,  readily  soluble  in  alcohol  and  in  ether.  It 
gives  a  greenish  color  with  Fe2Cl6.  Its  acetate  fuses  at  70°  (158°  F.) . 

Substituted  Naphthols. — Both  naphthols  form  a  great  number  of 
derivatives  by  substitution  of  other  groups  for  hydrogen  atoms. 
Many  of  these  are  important  dyes.  Thus  Martius  yellow  is  the  Na 
salt  of  2,  4-dinitro-a-naphthol,  a  poisonous  pigment  sometimes  used 
to  color  butter  and  confectionery.  Naphthol  yellow  is  the  dipotas- 
sium  salt  of  dinitro-a-naphthol-8-sulfonic  acid.  The  naphthols  com- 
bine easily  with  the  diazo-  and  azo- compounds  (p.  426)  to  form  a 
number  of  azo-naphthol  derivatives,  several  of  which  are  important 
dyes,  as  the  naphthol  oranges  and  Bieberich  scarlet.  A  great  va- 
riety of  naphthol-sulfonic  acids  have  also  been  prepared  for  use  in 
the  color  industry,  as  in  the  preparation  of  the  various  ponceau  and 
Bordeaux  dyes.  These  sulfonic  acids,  being  basic  by  their  OH 
group  and  acid  by  the  HSOs  group,  form  lactone-like  compounds 
(p.  320),  which  are  called  sultones. 

Tetrahydronaphthols  are  formed  by  the  introduction  of  four  H 
atoms  into  one  of  the  benzene  rings,  by  the  action  of  nascent  hydro- 
gen upon  the  naphthols.  If  the  hydrogenation  occur  in  the  ring 
containing  the  OH,  one  product  is  obtained,  designated  by  the  prefix 
ac-,  whereas  if  it  occur  in  the  other  ring  a  different  substance  is  pro- 
duced, designated  by  the  prefix  ar-. 

Anthraphenols.  —  Three  monophenols,   Ci4H9(OH),  are  known: 


444  MANUAL    OF    CHEMISTRY 

a  and  ft  anthrols,  which  behave  like  phenols  and  naphthols;  and  ms- 
(or  y)  oxyanthracene,  or  anthranol  (p.  442),  which  is  readily  oxi- 
dized to  anthraquinone  (below).     Two  Bz-dioxyanthracenes,  OH.- 
CeHa:  (CHhrCeHa.OH,  called  chrysazol  and  rufol,  are  also  known. 
Alcohols  of  this  series  are  known  ;  some  primary  :  as  the 
Naphthyl  Alcohols  —  Ci0H7.CH2OH—  which  are  formed  by  the 
action  of  nitrous  acid  upon  the  corresponding  amins  (p.  241).     The 
a  alcohol  fuses  at  50°;  the  ft  boils  at  80°. 

C1  TT 

Fluorene  Alcohol—  T   ^CH.OH—  f.   p.  153°,  is  formed  by  re- 

/ 


duction  of  fluorene  ketone  (below). 

Naphthyl  Aldehydes  —  CioH7.CHO  —  are  obtained  by  oxidation  of 
the  alcohols.  The  a  aldehyde  boils  at  291°;  the  ft  fuses  at  59°. 

The  ketones  are  either  ring  ketones,  such  as  those  of  indene  and 
fluorene,  or  the  CO  group  is  in  a  lateral  chain,  as  in  the  naphthalene 
ketones. 


^-Indone  —  CcH^^co/CH  —  is  known  in  its  Cl  and  Br  derivatives; 
also  a  and  ft  hydrindones,  C6H4  :  <      2/CH2  and  C6H 


rt  TT 

Fluorene  Ketone  —  Diphenylene  Ketone  —  I       /CO  —  f  .  p.  84°, 

' 


is  formed  by  oxidation  of  fluorene  with  chromic  acid  mixture,  and 

C6H4.COOH 
also  from  diphenic  acid,  I 

C6H4.COOH 

Naphthyl-  methyl  Ketone  —  CioH7.CO.CH3—  is  formed  by  the  ac- 
tion of  acetyl  chlorid  upon  naphthalene  in  presence  of  A^Cle. 

Both  aldehydes  and  ketones  form  oxims  and  hydrazones  (pp.  360, 
429). 

Quinones.  —  Naphthalene,  anthracene  and  phenanthrene  readily 
yield  quiuones  (p.  396),  some  of  which  are  technically  prepared  by 
oxidizing  the  hydrocarbons  in  acetic  acid  solution  by  chromic  acid  ; 
or  from  the  dioxy-  or  diamido-  compounds. 

Naphthoquinones.  —  Oxidation  of  naphthalene  produces  anaphtho- 
quinone,  CioHerO^M),  which  crystallizes  in  yellow  needles,  fusible  at 
125°.  The  a-ft  quinone,  CioHo:O2d,a),  is  formed  by  oxidation  of  ft 
amido-a-naphthol,  and  crystallizes  in  red  needles,  fusible  at  115°. 
Both  naphthoquinones  form  oxims  and  hydrazones,  some  of  which 
are  used  in  the  color  industry. 

Anthraquinone  —  Diphenylene  Diketone  —  CeH^:  (CO)2:CoH4  —  is 
commercially  manufactured  by  oxidation  of  anthracene.  It  forms 
yellow  needles;  f.  p.  285°;  b.  p.  382°.  It  forms  an  oxim  with  hydrox- 
ylamin,  and  sulfonic  acids  with  H^SOi,  as  well  as  chlorin,  bromin 
and  oxy-  derivatives. 


CONDENSED    CAEBOCYCLIC    NITROGEN    DERIVATIVES          445 


Alizarin  —  1,  2  -  Dioxyanthraquinone  —  CeH^  (CO)2:C6H2:  (OH)2— 
is  prepared  industrially  by  the  action  of  fused  NaHO  upon  anthra- 
quinone-monosulfonic  acid,  and  is  also  formed  by  fusion  of  several 
other  anthraquinone  derivatives  with  caustic  alkalies.  It  is  the  color- 
ing principle  of  madder  (Rubia  tinctoria)  ,  and  the  artificial  product 
has  now  completely  displaced  madder  in  dyeing. 

Purpurin—  1,2,  4-Trioxyanthraquinone  —  C6H4  :  (  CO  )  2  :  C6H  :  (  OH  )  3 
—  is  another  constituent  of  madder,  also  obtained  artificially  by  oxi- 
dation of  alizarin,  or  from  tribromo-  anthraquinone. 

Both  alizarin  and  purpurin  form  nitro-  and  amido-  substitution 
products  which  are  also  used  as  dyes;  alizarin  orange,  blue  and  brown. 

Several  oxymethylanthraquinones  are  active  principles  of  purga- 
tive drugs.  Chrysophanic,  or  rheic  acid,  which  exists  in  senna, 
rhubarb,  cascara,  goa-  powder,  is  dioxymethylanthraquinone,  CeH*: 
(C0)2  :  C6H.CH3  :  (OH)2.  Reducing  agents  convert  it,  first  into 
chyrsarobin,  CsoHseOyO),  which  also  exists  in  goa  -powder,  and 
finally  into  methylanthraquinone.  Emodin,  which  exist  in  Rhamnus 
frangula  (p.  412)  and  in  rhubarb,  is  trioxymethylanthraquinone, 
C6H4:(CO)2:C6.CH3:(OH)3. 

Carboxylic  Acids.  —  A  great  variety  of  acids  are  derivable  from 
indene,  hydrindene,  fluorene,  anthracene  and  phenanthrene  by  substi- 
tution of  COOH  groups  for  hydrogen. 

Naphthalene  Monocarboxylic  Acids  —  Naphthoic  Acids  —  CioH?.- 
COOH  —  are  formed  by  hydrolysis  of  their  nitrils.  The  «  acid 
fuses  at  160°;  the  0  at  182°.  Their  homologues  are  naphthyl-fatty 
acids.  They  form  a  great  variety  of  substitution  products,  nitro-, 
amido-,  etc.,  among  which  are  the  naphthol-carboxylic  acids,  CioHe.- 
OH.COOH,  which  readily  decompose  into  water  and  lactones  (p.  320)  . 
The  naphthalene  di-  and  poly-carboxylic  acids  are  very  numerous 
(p.  442),  the  best  known  being  naphthalic,  or  1,  8-naphthalene 
dicarboxylic  acid,  formed  by  the  oxidation  of  acenaphthene, 


NITROGEN   DERIVATIVES. 

Naphthalene,  anthracene,  and  phenanthrene  form  a  number  of 
nitro,  amido,  azo,  and  hydrazin  derivatives,  of  which  only  a  few  of 
the  naphthalic  compounds  require  brief  mention. 

Naphthylamins—  Amidonaphthalenes—  CioH7.NH2.  Both  a  and  /? 
compounds  are  formed  by  reduction  of  the  corresponding  nitro- 
naphthalenes,  CioH7.NO2;  or  by  the  action  of  ammonia  upon  the 
naphthols  in  presence  of  zinc  chlorid:  CioH7.OH+NH3=CioH7.NH2+ 
H20,  the  latter  a  method  of  formation  which  is  not  realized  with  the 
amidobenzenes  (p.  419).  The  <*  amin  crystallizes  in  flat  needles; 


446  MANUAL    OF    CHEMISTRY 

f.  p.  50°  (122°  F.) ;  b.  p.  300°  (572°  F.);  insoluble  in  water,  soluble 
in  alcohol  and  ether;  becomes  red  on  exposure  to  air;  1ms  a  per- 
sistent and  disagreeable  odor.  On  moderate  oxidation  it  forms  a 

blue  compound,  oxynaphthylamin,  CioH6\oH25  on  more  complete  oxi- 
dation a  naphthoquinone.  The  ft  amin  crystallizes  in  plates;  f .  p.  112° 
(233.6°  F.);  b.  p.  294°  (561.2°  F.);  dissolves  in  hot  water,  forming 
a  blue -fluorescent  solution.  On  oxidation  it  forms  phthalic  acid. 
Tetrahydro  /3-naphthylamin,  CioHn.NEb,  is  a  very  active  mydriatic. 

Several    naphthylamin-sulfonic   acids    are   manufactured    in   the 
color  industry,  as  well  as  diazo-  and  azonaphthalene  compounds. 


D.     DIPHENYL   AND   ITS   DERIVATIVES. 

Diphenyl,  CeHs.CeHs,  is  the  type  of  the  hydrocarbons,  known  as 
phenylbenzenes,  formed  by  the  substitution  of  phenyl,  toluyl,  benzyl, 
etc.,  for  atoms  of  hydrogen  in  benzene  (see  formula  of  p2-diamido- 
diphenyl,  p.  384).  Thus  we  have,  besides  diphenyl,  toluyl-benzene, 
Cells.  CeHi.CHs,  diphenyl-benzene,  CeEU:  (CeHs)2,  and  triphenyl- 
benzene,  CeHs  :  (CeHsh.  These  hydrocarbons  are  the  parent  sub- 
stances of  a  great  number  of  substitution  products.  The  monosub- 
stituted  compounds  are  o-,  in-,  or  p-,  with  reference  to  the  point  of 
union  of  the  benzene  rings.  In  the  bi-  and  polysubstituted  deriva- 
tives the  substituents  may  be  introduced  into  the  same  or  into  diifer- 
ent  rings.  Bi- substitution  of  bivalent  groups  for  H2  in  the  op- 
positions produces  compounds  belonging  to  other  series  of  our 
classification.  Thus  fluorene  and  phenanthrene  (p.  441)  are  deriva- 
ble from  diphenyl  by  substitution  of  -CHs-  and  of  -CH.CH-  respect- 
ively in  the  0-02-  positions.  Diphenylene  oxid  and  sulfid  and  car- 
bazole  (p.  467)  are  similarly  derivable  from  diphenyl  by  substitution 
of  O,  S,  and  NH. 

Diphenyl — Phenylbenzene — CeHs.  Cells — exists  in  small  quantity 
in  gas -tar.  It  is  formed  by  the  action  of  sodium  upon  monobromo- 
benzene:  2CeH5BrH-Na2=CeH5.C6H5+2NaBr;  or  by  passing  benzene 
vapor  through  a  red-hot  tube;  or  by  the  interaction  of  diazoben- 
zene  chlorid  and  benzene  in  presence  of  aluminium  chlorid:  CeHs.- 
N:NC1+C6H6=C6H5.C6H5-|-HC1+N2.  It  crystallizes  in  large  plates; 
f.  p.  70°  (158°  F.);  b.  p.  254°  (489.2°F.);  soluble  in  glacial  acetic 
acid  and  in  amylic  alcohol.  Nascent  hydrogen  converts  it  into 
tetrahydro-diphenyl,  Ci2Hi4.  With  methylene  chlorid,  in  presence  of 

Al2Cl6it  forms  fluorene:  C6H5.C6H5+CH2Cl2=C6H4.CH2.C6H4+2HCl. 
Difluor-diphenyl,  CeH^F.Cel^F,  is  a  white,  crystalline  powder,  used 
as  an  antispasmodic  under  the  name  antitussin. 


DIPHENYL-PARAFFINS,    OLEFINS    AND    ACETYLENES          447 

Amido-diphenyls,  toluyls,  etc.,  can  be  obtained  by  reduction  of 
the  corresponding  nitro- compounds.  One  of  these,  benzidin,  or 
p2-diamido-diphenyl  (formula  p.  384),  is  a  product  of  technical  im- 
portance, which  is,  however,  manufactured  by  reduction  of  azoben- 
zene  in  acid  solution.  Azobenzene,  CeEU.NrN.CeHs,  first  forms  hy- 
drazobenzene,  CeHs.NH.NH.CeHs  (p.  428),  which  by  further  hydro- 
genation  and  transposition,  yields  benzidin,  NJ^^.CeEU.CeEU.NEbu). 
Benzidin  serves  for  the  manufacture  of  a  number  of  azo  dyes,  which 
are  sulfonic  or  carboxylic  acids,  or  their  salts.  Among  these  benzi- 
din dyes  are  Congo -yellow  and  Congo -red. 

Oxydiphenyls  are  the  phenols  of  these  hydrocarbons,  and  are 
formed  by  fusing  the  benzenic  phenols  with  KHO.  The  hexaoxy- 
diphenyl  derived  from  pyrogallol  (p.  395)  yields  a  quiuone  (p.  396) 
whose  methylic  ester  is  coerulignone,  C^rC^HeCOCHah,  the  amido 
derivatives  of  which  form  a  number  of  blue,  violet  and  black  dyes. 


E.     DIPHENYL-PARAFFINS,    DIPHENYL-  OLEFINS, 
DIPHEN  YL  -  ACETYLENES  . 

The  hydrocarbons  of  this  series  may  be  considered  as  derived 
from  the  aliphatic  hydrocarbons  by  substitution  of  two  (or  more) 
phenyl  groups  for  hydrogen  : 


Hs  —  Phenyl-methane=Toluene=Methyl-benzene  (p.  386). 

CfiHs.CHo.CeHs  —  Diphenyl-methane=Benzyl  -benzene  (formula  p.  384). 
(  C6H5  )  2  :  CH  .  C0H5—  Triphenyl  -methane  . 
(C<jH5)2:Si:(C6H5)2  —  Tetraphenyl-  silicon  (C  compound  unknown). 

C6H5.CH2.CH2.C6H5—  Sym.  Diphenyl  -ethane=Dibenzyl. 
(C6H5)2:CH.CH3—  Unsym.  Diphenyl-  ethane. 

C6H5.CH  :CH.C0H5—  Sym.  Diphenyl  -ethylene=Stilbene. 

CoH5.C=C.C6H5—  Diphenyl-acetylene=Tolane. 

Diphenyl  -methane  —  Benzyl  -benzene  —  is  produced  by  the  action 
of  benzyl  chlorid  upon  benzene  in  presence  of  aluminium  chlorid: 
CGH5.CH2.C1+C6H6  =  C6H5.CH2.C6H5+HC1.  It  is  a  crystalline  solid; 
f.  p.  27°  (80.6°  F.)  ;  b.  p.  262°  (503.6°  F.)  ;  soluble  in  alcohol,  ether, 
and  chloroform;  has  an  odor  resembling  that  of  the  orange. 

Triphenyl-  methane  —  is  formed  by  the  action  of  chloroform  upon 
benzene  in  presence  of  aluminium  chlorid:  SCeHe-fCHCls^CeHsh: 
CH.C6H5+3HC1.  It  is  a  crystalline  solid;  f.  p.  92°  (197.6°  F.)  ;  b.  p. 
360°  (680°  F.);  soluble  in  ether  and  in  chloroform.  It  is  converted 
into  a  trinitro-  derivative  by  fuming  HNOs;  and  this,  in  turn,  is  con- 
verted by  nascent  H  into  leuco-pararosanilin,  CH.(C6H4.NH2)3. 

Stilbene  —  Toluylene  —  Sym.  Diphenyl  -ethylene  —  is  formed  by 
distillation  of  benzyl  sulfid;  by  reduction  of  benzoic  aldehyde;  or  by 


448  MANUAL    OF    CHEMISTRY 

distillation  of  the  phenylic  esters  of  fumaric  (p.  375)  or  cinnamic 
(p.  402)  acids.  It  forms  large,  glistening  prisms  or  plates;  f.  p. 
124°  (255.2°  F.)  ;  b.  p.  306°  (582.8°  F.).  It  forms  a  number  of 
haloid  and  other  derivatives. 

Tolane — Diphenyl- acetylene — is  formed  by  the  action  of  KHO 
upon  stilbene  bromid.  It  is  a  crystalline  solid;  f .  p.  60°  (140°F.). 

Diphenyl-diacetylene  —  C6H5.C=C.C=C.C6H5  —  is  formed  by 
moderate  oxidation  of  copper  phenyl-acetylid,  Cells. (SC.Cu.C=C.- 
C6H5,  as  a  crystalline  solid;  f.  p.  88°  (190.4°  F.).  Its  o,  o2-dinitro- 
derivative  is  converted  into  indigo -blue  (p.  466)  by  reduction. 


PHENOLS,  ALCOHOLS,  KETONES,  AND  CARBOXYLIC  DERIVATIVES. 

Phenolic  derivatives  of  these  hydrocarbons  are  known,  which 
contain  hydroxyls  in  one  or  more  of  the  phenyl  groups. 

Diphenyl  Carbinol  —  Benzhydrol  —  CeHs.CHOH.CeHs  —  is  the  sim- 
plest alcohol  of  this  series.  It  is  formed  in  colorless  crystals;  f.  p. 
68°;  b.  p.  298°;  by  reduction  of  benzophenone  with  sodium  amal- 
gam, C6H5.CO.C6H5  +  H2  =  C6H5.CHOH.C6H5.  Its  tetramethyl- 

diamido-  derivative,  CHOH\(j^lN(CT^)!»  f°rms  colorless  crystals, 
which  dissolve  in  acetic  acid  with  an  intense  blue  color.  It  is 
formed  by  the  action  of  lead  peroxid  and  acetic  acid  upon  tetra- 
methyl-diamido-diphenyl  methane,  which  is  produced  by  heating 
dimethyl  anilin  with  formaldehyde  and  a  little  sulfuric  acid  :  2CeH5.- 

These    reactions   are 


used  as  a  test  for  formaldehyde. 

Triphenyl  Carbinol,  (CeHshC.OH,  and  diphenyl-m-toluyl  car- 
binol,  (C6H5)2:C(OH).C6H4.CH3(3),  are  alcohols,  whose  triamido- 
derivatives  are  pararosanilin  and  rosanilin.  They  are  formed  by 
oxidation  of  the  hydrocarbons.  They  form  nitro-  and  amido-  deriva- 
tives of  technical  importance. 

The  benzophenones,  the  ketones  of  this  series,  correspond  to  the 
phenones  (p.  400),  from  which  they  differ  in  containing  two  phenyls 
in  place  of  one;  and  they  bear  the  same  relation  to  the  benzoic  acids 
that  the  acetones  (p.  261)  do  to  the  fatty  acids.  They  are  produced 
by  oxidation  of  the  hydrocarbons  ;  by  the  action  of  P2Os  upon  a 
mixture  of  a  benzene  hydrocarbon  and  a  benzoic  acid;  or  by  the 
action  of  phosgene  or  of  an  acidyl  chlorid  upon  benzene  in  presence 
of  aluminium  chlorid. 

Benzophenone  —  Diphenyl-ketone  —  CeHs.CO.CeHs  —  forms  large 
rhombic  prisms;  f.  p.  48°  (118.4°  F.);  b.  p.  305°  (581°  F.);  soluble 
in  alcohol  and  ether.  Sodium  amalgam  reduces  it  to  benzhydrol, 


NITROGEN  -CONTAINING    DERIVATIVES  449 


or  diphenyl  carbinol,  (CeHshrCH.OH.  Benzophenone  is  the  parent 
substance  of  a  great  number  of  substitution  products,  some  of  which 
are  used  in  the  color  industry. 

Benzoin—  C6H5.CH(OH).  CO.  C6H5—  which  exists  in  crude  oil  of 
bitter  almonds,  is  a  keto-  alcohol  corresponding  to  hydrobenzoin,  or 
toluylene  glycol,  C6H5.CH(OH).CH(OH).C5H5,  which  is  formed  by 
the  action  of  nascent  H  upon  benzoic  aldehyde  (p.  398). 

Benzil  —  Dibenzoyl  —  CeHs.CO.CO.CeHs  —  is  a  diketone,  obtained 
by  the  action  of  moist  silver  oxid  upon  stilbene  bromid. 

Carboxylic  acids  derived  from  the  diphenyl  -methanes,  such  as 
benzoyl-benzoic  acids,  CeHs.CO.CeHi.COOH,  and  acids  derived  from 
stilbene  and  from  diphenyl  -diacetylene  are  known.  But  few  of  the 
carboxylic  acids  derivable  from  triphenylmethanes  are  known,  owing 
to  their  tendency  to  lose  water  and  form  lactones.  Among  these 
lactones  are  the  phthalei'ns  and  numerous  other  dyes,  such  as  rosolic 
acid  and  the  aurines. 

The  phthalids  of  this  class  may  be  considered  as  derived  from 

phthalid  (p.  407),  CeHJHO,  which  is  the  lactone  of  o-oxyme- 


thylbenzoic  acid,  CeHOllo,)'  ^v  substitution  of  phenyl  for  hydro- 
gen in  the  Clb  group.    Thus  diphenyl  phthalid,  obtained  by  oxidation 

/r*OOTT 

of   triphenyl  methane  o-carboxylic  acid,  C6H4\CH(Cejj5)2(a),  has  the 
constitution:   CeH       J^O        .    The  phthalei'ns  have  been  consid- 


ered  as  oxy  phenyl  ketonic  derivatives  of  phthalic  acid,  as  indicated 
on  p.  396,  or  as  lactones  derivable  from  phthalid  by  substitution  of 

oxyphenyl  groups.     Thus  phenol  phthalem,  Ce 


NITROGEN-CONTAINING   DERIVATIVES. 

Among  the  great  number  of  nitro-  and  amido- derivatives  of  these 
hydrocarbons  the  most  important  are  the  amido -derivatives  of  tri- 
phenyl-carbinol  (p.  448).  From  those  in  which  two  or  three  of  the 
amido  groups  occupy  the  para  positions  with  regard  to  the  C(OH) 
group,  or  from  their  alkyl  derivatives,  a  number  of  important  dyes, 
red,  green,  violet,  blue,  and  brown,  are  manufactured. 

p-Amido-triphenylmethane — (C6H5)2:  CH.CeELi.NEku) — is  formed 
by  the  action  of  benzhydrol  upon  anilin  chlorid  in  presence  of 
zinc  chlorid.  The  corresponding  carbinol  forms  salts  which  have  no 
coloring  power. 

p2-Diamido-triphenylmethane — C6H5.CH:  (C6H4.NH2U))2 — is  pro- 
duced by  the  interaction  of  anilin  chlorid  and  benzoic  aldehyde  in 

29 


450  MANUAL    OF    CHEMISTRY 

presence  of  zinc  chlorid,  and  by  other  methods.  The  base  is  a  yellow, 
imperfectly  crystalline  solid,  insoluble  in  water,  soluble  in  alcohol  and 
in  benzene;  which  forms  blue  salts.  The  corresponding  carbinol, 
CeHs.CfOH) :  (CeHi.NH^h  forms  a  chlorid  which  is  a  reddish- violet 
dye. 

p2-Tetramethyl  -  diamido  -  triphenylmethane  —  CeHs.OH:  [CeH^- 
N(CH3)2(4)]2 — is  manufactured  by  the  action  of  sulfuric  or  hydro- 
chloric acid  upon  benzoic  aldehyde  and  dimethyl -anilin.  It  and  its 
carbinol  are  almost  colorless  bases,  which  form  salts  which  are 
brilliant  green  dyes,  leucomalachite  green  and  malachite  green,  or 
bitter  almond-oil  green. 

Triamido-triphenyl  methanes  and  their  alkyl  derivatives  (see 
below)  are  known  as  leucanilins  (^.«>Kos=white)  from  the  fact  that, 
while  some  of  their  derivatives  are  brilliantly  colored,  they  are  color- 
less, or  nearly  so.  By  oxidation  they  yield  carbinols,  formed  by  the 
substitution  of  OH  for  H  in  the  connecting  group  CH,  known  as 
rosanilins,  which  are  powerful  triacid  bases,  whose  salts  are  the  dyes 
referred  to.  The  most  important  industrially  are  those  having  at 
least  two  amido- groups  in  para  positions.  Their  constitution  is 
indicated  by  the  folio  wing -formulae  : 

H 

OK=> 


NH2 


o-pa— Triamido-triphenyl  methane  m-p2— Triamido-triphenyl  methane 

( o-Leucanilin) .  ( Pseudoleucanilin) . 


H2N-<          >-C-<          >-NH2          H2N-<          >-C-<          >-NH2 


NH2  NH2 

p3-Triamido-triphenyl  methane  pa-Triamido-diphenyl-m-toluyl  methane 

( Paraleucanilin ) .  ( Leuc  anilin  ) . 

or,  by  a  different  form  of  expression  for  the  corresponding  carbin- 
ols; the  rosanilins: 

/C6H4.NH2(4)  /C0H4.NH2(4) 

HO.C— C6H4.NH2(4)  HO  C— CoH4.NH2U) 

\C6H4.NH2(2)  \C6H4.NH2(3) 

/C6H4.NH2(4)  /C6H4.NH2(4) 

HO.C— C0H4  .NH2.4,  HO.C— C6H4  .NH2(4) 

\CoH4.NH2(4) 


NITROGEN -CONTAINING    DERIVATIVES  451 

Of  these  the  pa-triphenyl,  and  the  ps-diphenyl-m-toluyl  carbin- 
ols  and  their  methyl,  ethyl,  benzyl,  and  phenyl  derivatives  are  ex- 
tensively used  in  the  color  industry.  Fuchsine,  anilin  red,  or 
magenta  consists  chiefly  of  the  acetate  or  hydrochlorid  of  ps-tri- 
amido-diphenyl-m-toluyl  carbinol,  or  rosanilin.  It  is  manufactured 
by  oxidation  of  "anilin  oil"  (p.  420),  which  is  a  mixture  of  anilin, 
and  o-  and  p-toluidin,  by  heating  with  a  mixture  of  nitro- benzene, 
hydrochloric  acid,  and  iron  filings.  Formerly  arsenic  acid  was  used 
as  anoxidant,  when  the  fuchsin  was  obtained  as  a  poisonous  arsenite. 
Fuchsin  forms  green  crystals,  having  a  metallic  luster,  soluble  in 
water  and  in  alcohol,  to  which  it  communicates  a  bright-red  color. 
This  color  is  discharged  by  sulfurous  acid,  and  regenerated  by  alde- 
hydes, and  such  a  decolorized  magenta  solution  is  used  as  a  reagent 
for  the  detection  of  aldehydes  (Schiff's  reagent). 

By  the  action  of  methyl  iodid  upon  fuchsin  a  number  of  methyl- 
ated derivatives  are  obtained,  which  are  violet  dyes,  such  as  crystal 
violet,  Hofmann's  violet,  dahlia,  etc.  By  further  methylation  of 
the  violets,  green  dyes  are  formed,  as  the  iodin  greens,  and  aldehyde 
green.  By  substitution  of  phenyl  in  place  of  methyl,  a  number  of 
blue  dyes,  as  Lyons  blue,  soluble  blue  and  alkali  blue  are  ob- 
tained. Pyoktanin -blue,  dahlia,  is  penta-  and  hexa-methyl  para- 
rosanilin  hydrochlorid,  produced  from  dimethyl  anilin.  It  is  a  violet 
powder,  soluble  in  water  and  .very  diffusible,  non- poisonous  and 
used  internally  as  an  antiseptic.  Pyoktanin-yellow,  used  medici- 
nally for  the  same  purposes  as  the  blue,  is  the  hydrochlorid  of  imido- 

tetramethyl-diamido-diphenyl  methane,   HH:0^§§3;(§^J..    Tri- 

phenyl  -  pararosanilin,  HO.C  ;  (  C6EU.NH. Cells  h,  is  the  base  of  a 
number  of  blue  dyes,  among  which  is  methyl  -  blue,  the  sodium  salt 
of  its  trisulfonic  acid,  which  has  been  used  locally  in  diphtheria. 
It  is  poisonous,  and  has  caused  death  by  its  administration  in  mis- 
take for  methylene-blue  (p.  459). 


452  MANUAL    OF    CHEMISTRY 


HETEROCYCLIC    COMPOUNDS. 

These  compounds  differ  from  the  carbocyclic  in  that  they  contain 
elements  other  than  carbon  as  constituents  of  the  nuclei.  They 
form  series  parallel  to  the  carbocyclic,  from  which,  indeed,  they  may 
be  considered  as  being  derived  by  substitution  in  the  rings.  Thus 
thiophene  corresponds  to  pentole,  pyridin  to  benzene,  and  quinolin 
to  naphthalene: 

H  H          H 

C  C  C 

/  \  S  \  /  \ 

HC CH  HC          CH  HC  C  CH 

II  I  I  II  I 

HC          CH  HC  C  CH 

vJV  \  /  \  / 

C  C  C 

H  H  H 

Benzene.  Naphthalene. 

H  H  H 

C  C  C 

/  \  s  \  /  \ 

HC CH  HC  CH  HC          C  CH 

II  II  II  I  I  II  I 

HC  CH  HC  CH  HC          C  CH 

\  /  \  ^     •  \,/  \  S 

S  N  C  N 

H 
Thiophene.  Pyridin.  Quinolin. 

The  elements  which  can  be  thus  introduced  into  a  cyclic  nucleus 
are  few  ;  oxygen,  sulfur,  selenium,  phosphorus  and  nitrogen  being 
the  only  ones  now  known  to  enter  into  such  formation,  and  of  these 
the  nitrogen -containing  compounds  are  far  the  most  numerous  and 
the  most  important.  The  facility  with  which  the  N  atom  takes  the 
place  of  the  methine  group, —  CH=,  in  the  benzene  ring  is  to  be 
anticipated  from  their  equivalence.  Pyridin  also  resembles  benzene 
in  its  general  characters,  and,  on  the  other  hand,  the  five  membered 
compounds,  furfurane,  thiophene  and  pyrrole,  have  general  charac- 
ters similar  to  those  of  benzene,  from  which  they  may  be  considered 
as  being  derived  by  substitution  of  the  bivalents  O,  S,  and  NH  for 
one  of  the  three  acetylenes, —  CH:CH — ,  of  benzene.  The  number 
of  hetero- atoms  which  may  be  contained  in  the  nucleus  is  not 
limited  to  one,  and  five  and  six  membered  rings  containing  as  many 
as  four  nitrogen  atoms,  the  tetrazoles  and  tetrazins,  are  known. 

A  classification  of  the  heterocyclic  compounds  requires  many 
subdivisions,  because  of  the  great  number  and  variety  of  these  sub- 
stances, due  to  the  presence  of  one  or  more  atoms  of  one  or  more 


HETEEOCYCLIC    COMPOUNDS  453 

of  the  elements  above  mentioned,  in  three,  four,  five  or  six  mem- 
bered  rings,  contained  in  mono-,  di-,  tri-,  or  tetra-  nucleate  mole- 
cules, in  which,  also,  differences  in  the  ring  -valence  are  caused  by 
differences  in  internal  linkage.  A  broad  classification  may,  however, 
be  here  followed,  somewhat  similar  to  that  for  the  aromatic  sub- 
stances (p.  384). 

A.  Mono  -nucleate  compounds:  containing  a  single  nucleus.    These 
may  be  subdivided  into:  (a)  Substances  containing  three  -  membered 

H2C 


rings;    such    as    ethylene   oxid,        I  /O,  sulfid,      I  /S,    and    imid, 


H2C 


H2C  H2C 


\ 


NH. 


(b)  Four-membered    compounds,    such    as    trimethylene    oxid, 
H2C— O  H2C— O  H2C— CH2 

I     I      ,  thetin,      I     I  ,  and  trimethylene  imid,      I     I     . 
H2C— CH2  H2C— S  HoC— NH 


LX 

HC=CH' 
HC=CH> 


(c)  Five-membered  substances,  such  as  furfurane,  _l    _  /0,thi- 


ophene,     I          /S,  and  pyrrole,      I         /NH. 
/  / 


V 
/ 
HC=CH/  HC=CH 

HC-CH=CH 
(d)  Six-  membered  compounds,  such  as  pyridin,     II  I    ,  pi- 

HC  —  CH=N 

H2C—  CH2—  CH2  N=N—  CH 

peridin,      I  I      ,  and  sym.  tetrazin,      I          II    . 

H2C—  CH2—  NH  HC=N-N 

The  five-  and  six  -membered  compounds  are  much  more  numerous 
and  important  than  the  three-  and  four  -membered. 

B.  Condensed  compounds,  containing  two  or  more  rings,  usually 
five-  or  six  -membered,  of  which  at  least  one  is  heterocyclic,  fused 
together,  and  having  two   carbon  atoms  in  common.     These  com- 
pounds, which   correspond   to   the   condensed   benzenic   compounds 
(p.  438),  include  the  indole,  quinolin,  anthraquinolin,  quinoquinolin, 
and  diphenylene  derivatives. 

C.  Compounds  containing  two  (or  more)  nuclei,  one  at  least  hete- 
rocyclic, united   directly  without  fusion,   corresponding  to   the  di- 
phenyls,  and   including  phenyl-pyridyl,  dipyridyl,    pyridyl-  pyrrole, 
and  pyridyl  -piperidyl  derivatives. 

D.  Compounds   containing  two   (or  more)   nuclei,  one   at   least 
heterocyclic,    united    by    aliphatic    groups,    corresponding    to    the 
diphenyl-  paraffins,    and    including    the    "  ester  -alkaloids"    such    as 
atropin,  cocain,  etc. 

In  a  more  detailed  classification  the  members  of  the  several  classes 
are  subdivided  into  the  groups  of  mono-,  di-,  tri-,  and  tetrahetero- 
atomic  compounds,  according  as  they  contain  one,  two,  three  or  four 
atoms  other  than  carbon,  of  like  or  different  kinds,  in  the  ring. 


454  MANUAL    OF    CHEMISTRY 

A.-MONONUCLEATE   HETEROCYCLIC   COMPOUNDS. 

FIVE    MEMBERED   RINGS. 

The  parent  substances  of  these  compounds  are  furfurane,  thio- 
pheiie,  and  pyrrole*  (see  p.  453). 

The  heterocyclic  rings  differ  from   the   carbocyclic   in  that  the 
several  carbon  atoms  are  not  equal  in  value,  and  therefore  two  dif- 

ferent    monosubstituted   deriva- 

C  tives  exist  for  the  five  membered 

/t\  rings  containing  a  single  hetero- 

^/H||~    ~IJH/}  ^H          J^       atom'    such   as   furfurane>    and 

HC          CH  HC         CH        three   such    compounds    in    six 

^o/  a/NyN  membered  rings,  such  as  pyri- 

Furfurane.  Pyridin.  din,  according   to   the   position 

of   substitution   with    reference 

to  the  hetero-atom.  These  positions  are  distinguished  by  the  first 
three  letters  of  the  Greek  alphabet,  as  shown  in  the  margin,  or, 
sometimes  by  numbers.  The  positions  a  and  <*',  and  p  and  $'  are 
of  equal  value. 


v 

Furfurane  —    I          /O  —  exists  in  the  product  of  distillation  of 
HC=CH/ 

pine  and  fir  wood,  and  is  also  formed  by  distillation  of  barium  pyro- 

HC-CH2x 

mucate  (below),  and  from  dihydrofurfurane,  II  /O,  a  product 

HC  —  CH2 

of  reduction  of  erythrol  (p.  254).  It  is  a  liquid;  b.  p.  32°  (89.6° 
F.)  ;  having  a  peculiar  odor.  Its  vapor  colors  a  pine  shaving  moist- 
ened with  HC1  green  (pp.  390,  455). 

HC=C—  CHO 
a-Furfuraldehyde  —  Furfurole  —  Furole  —     I      *^^    —  is  produced 

HC=CH—  O 

by  the  dry  distillation  of  sugar  or  of  wood;  by  the  distillation  of 
these  substances,  or  of  bran,  carbohydrates  or  glucosids  with  dilute 
H2SO4;  by  the  action  of  the  concentrated  acid  upon  sugar;  and  by 
distilling  pentoses  (p.  265),  or  glucuronic  acid  (p.  299)  with  HC1. 
It  is  a  colorless  liquid;  agreeable  in  odor;  b.  p.  162°  (323.6°  F.); 
soluble  in  water  and  in  alcohol.  Being  an  aldehyde,  it  undergoes  the 
reactions  common  to  those  substances.  In  concentrated  solution, 
with  urea  and  a  trace  of  acid,  it  is  colored  yellow,  changing  to  blue, 
to  violet  and  to  purple,  and  finally  fading,  with  formation  of  a  black 
precipitate  (Schiff's  reaction).  It  produces  a  red  color  with  anilin,.a 
very  sensitive  reaction  for  its  presence.  Paper  moistened  with  anilin 

*The  usual  spelling  Is  pyrrol,  furfurol,  indol.    The  terminal  e  is  used  because  these  gubstanceg 
are  neither  alcohols  nor  phenols,  for  whose  names  the  termination  ol  is  reserved. 


FIVE    MEMBERED    HETEROCYCLIC    RINGS  455 

acetate  solution  is  used.  Adamkiewicz'  and  Liebermann's  reactions 
for  the  proteins,  and  Pettenkofer's  reaction  for  the  biliary  salts,  etc., 
depend  upon  the  formation  of  furfurole. 

HC=C— COOH 
a-Furfurane  Carboxylic  Acid— Pyromucic  acid—    I      ^^      — 

HC=CH— O 

the  acid  corresponding  to  furfurole,  is  produced  from  that  substance 
by  oxidation,  also  by  distillation  of  mucic  and  isosaccharic  acids 
(p.  297).  It  is  a  solid;  f.  p.  134°  (273.2°  F.). 

HC=CHV 
Thiophene —    I         /S — and   its   superior  homologues,  methyl- 

HC=CH 

thiophenes,  etc.,  occur  in  gas -tar,  and  accompany  the  various  prod- 
ucts, benzene,  etc.,  obtained  from  it.  It  is  a  colorless  liquid;  b.  p. 
84°  (111.2°  F.);  which  is  so  nearly  that  of  benzene,  80.5°,  that  the 
two  substances  cannot  be  separated  by  distillation.  With  sulfuric 
acid  and  isatin  it  gives  a  fine  blue  color,  due  to  formation  of  indo- 
phenin.  Sulfuric  acid  alone  is  colored  brown  by  thiophene,  which  it 
absorbs;  and  thiophene  may  be  recovered  from  the  solution  by  neu- 
tralization and  distillation. 
HC=CH> 


Pyrrole — _J[    n   /NH — exists  in  coal-tar  and  accompanies   the 


L\i 

HC=CH' 

pyridin  bases  (p.  459)  in  oil  of  Dippel.  It  is  formed  in  a  great  variety 
of  reactions,  as  by  the  action  of  baryta  at  150°  (303°  F.)  upon 
albumens,  by  the  dry  distillation  of  gelatin  or  of  ammonium  saccha- 
rate,  etc.  It  is  a  colorless,  oily  liquid,  having  the  odor  of  chloro- 
form; b.  p.  131°  (267.8°  F.).  Being  a  secondary  amin,  it  has  basic 
properties,  and  its  imid  hydrogen  is  readily  replaced  by  other  atoms 
or  groups.  A  pine  shaving  moistened  with  HC1  is  colored  flame -red 
by  pyrrole  (the  pine-shaving  reaction;  see  also,  Phenol,  p.  390).  It 
also  yields  an  indigo -blue  color  with  H2S04  and  isatin.  Heated  with 
dilute  acids  it  gives  off  ammonia,  and  a  red  powder  (pyrrole  red)  is 
deposited. 

The  homologous  pyrroles,  methyl -pyrroles,  etc.,  have  reactions 
similar  to  those  of  pyrrole. 

Pyrrole  and  its  homologues  form  series  of  substitution  products: 
haloid,  nitro-,  azo-,  carboxylic,  etc.  Among  these  is  tetriodopyrrole, 
or  iodol,  C^NH,  formed  as  a  brown  powder  by  acting  upon  pyrrole 
with  an  ethereal  solution  of  iodin,  and  used  in  surgery  as  a  sub- 
stitute for  iodoform,  over  which  it  has  the  advantage  of  being 
odorless. 

Hydropyrrole    Derivatives — Nascent    hydrogen    combines    with 

CH  :CHV 

pyrrole  to  form,  first  dihydropyrrole,  or  pyrrolin,  I  yNH,    an 

CH2.CH2 

alkaline  liquid,  soluble  in  water;  b.  p.  91°;  and,  finally,  tetrahydro- 


456 


MANUAL    OF    CHEMISTRY 


CH2.CH2y 

pyrrole,  or  pyrrolidin,  or  tetramethylene-imin,   I  yNH,  which 

CH2.CH2 

bears  the  same  relation  to  pyrrole  that  piperidin  does  to  pyridin 
(p.  461).  Pyrrolidin  resembles  piperidin  in  its  reactions,  and  also 
forms  an  addition  product  with  methyl  iodid.  It  is  formed  by  heating 
tetramethylene-diamin  hydrochlorid  (p.  333) :  H2N.  (CH2)4.NH2.HC1  = 
NH4CI+ (01X2)4: NH,  and  constitutes  the  nucleus  of  the  hygrins 
(p.  472)  and  one  of  those  of  nicotin  (p.  474).  It  is  a  strongly  alka- 
line liquid;  b.  p.  87°.  Among  the  derivatives  of  pyrrolidin  is  pyrroli- 

CH2.CHV 
done,  or  butyrolactam,  I  /NH,  a  simple  cyclic  imid  derived  from 

7-amidobutyric  acid  (p.  362). 


AZOLES  AND  THEIR  DERIVATIVES. 

The  azoles  are  derivable  from  furfurane,  thiophene  and  pyrrole 
by  substitution  of  one  or  more  nitrogen  atoms  for  inethine  groups. 
They  are  distinguished,  according  to  their  parent  substances,  and  the 
number  of  nitrogen  atoms  introduced,  as  furo-monazoles,  thio-diazoles, 
pyrro-triazoles,  etc.  There  are  nine  of  each  of  these  classes  of  sub- 
stances known  either  as  the  parent  substance  or  in  some  of  its 
derivatives.  They  are  distinguished  by  the  lettering  indicating  the 
position  or  positions  of  the  non-imid  nitrogen.  Thus  we  have  the 
following  pyrazoles: 


HC- 


HC 

\    / 

N 

H 

Pyrrole. 


CH 


N 


N 

II 
CH 


HC 
\    / 

N 

H 

/3-/3'-Diazole. 


HC CH 

II         II 
HC        N 

V 

H 

a-Monazole. 

HC N 

II  II 

N        CH 

V 

H 

a'-/3-Diazole. 


N 


CH 


HC- 
II 
HC 

N 

H 

/3-Monazole. 


HC 

II 

N 
\ 


HC  CH 

ii         H 

HC  N 

ii          H 

II         II 

N        N 

II          II 
HC        N 

\    / 

\    / 

N 

N 

H 

H 

a-a'-Diazole. 

a-/3-Diazole. 

N 
II 
N 


N 
II 
CH 


\ 


N 

II 

N 

\ 


a/-a-/3-Triazole.       a-jS-jS'-Triazole.  Tetrazole. 


Corresponding  to  each  of  these  are  derivatives,  formed  by  substi- 
tution and  by  modification  of  the  internal  linkages.  Those  derived 
from  pyrro-a-monazole  are  the  most  important,  and  may  serve  as 
types.  The  n-phenyl  derivatives  (those  in  which  CeHs  is  substituted 
for  H  in  NH)  are  the  best  known,  and  the  most  readily  obtainable. 
Pyrro-a-monazole,  or  pyrazole,  is  reduced  by  sodium  to  dihydropyr- 


FIVE    MEMBERED    HETEROCYCLIC    RINGS  457 

azole,  or  pyrazolin  (formula  below) ;     The  phenyl  derivative  of   a 
tetrahydropyrazole,  phenyl-pyrazolidin,  is  also  known. 

The  pyrazolons  are  ketonic  derivatives  of  the  pyrazolins,in  which 
O  takes  the  place  of  Ek  in  the  a- position.  Thus: 

HC CH  HC CH  H->C CH  H2C CH 

II         II  II         II  I         II  I         II 

HCf        CH  HC        N  H2C        N  OC        N 

\    /                       \   /                         \    /  \/ 

N                               N                                N  N 

H                               H                                H  H 

Pyrrole.  Pyrazole.  Pyrazolin.  Pyrazolon. 

The  pyrazolons  are  obtained  from  the  hydrazones  (p.  429)  of  the 
esters  of  the  /?  ketone  acids  (p.  298)  by  elimination  of  alcohol,  or  by 
the  action  of  phenylhydrazin  upon  these  esters  themselves.  Thus 
1,  3-phenylmethyl-pyrazolon  is  formed  either  from  phenylhydrazone- 
acetoacetic  ester: 

COO(C2H5)  H2C C.CH3 

CH2 

C:N.NH.C6H5        =        OC        N  + 

I  \    / 

CH3  N 

C«H5 

or  from  aceto- acetic  ester  and  phenylhydrazin: 

COO(C2H5)  H2C C.CH3 

CH2 


f 

CH3 


H2N.NH.C6H5        =       OC        N  -f      C2H5.OH+H2O. 

\    / 

N 
C6H5 


Antipyrin  —  1,  2,    3   (or  n-a-/2) — Phenyldimethyl   Pyrazolon  — 
CeH5N.CO.CH 

I         II        — is  formed,  as  its  hydroiodid,  by  heating  1,  3-phenyl- 
CH3N C .  CH3 

methyl  pyrazolon,  formed  by  the  second  reaction  given  above,  with 
methyl  iodid  and  methylic  alcohol  to  100°  (212°  F.)  in  sealed  vessels. 
It  forms  colorless,  odorless  scales,  somewhat  bitter  in  taste;  f .  p. 
110.5°  (230.9°  F.).  A  mixture  of  equal  parts  of  antipyrin  and 
antifebrin  (f.  p.  112.5°)  fuses  at  45°  (113°  F.).  Antipyrin  is  readily 
soluble  in  water,  alcohol  and  chloroform,  less  soluble  in  ether.  With 
nitrous  acid  or  the  nitrites  (sp.  a3th.  nitr.),  in  the  presence  of  free 
acid,  it  forms  a  green,  crystalline,  sparingly  soluble  nitro- derivative, 
which  is  poisonous.  Its  solution  is  colored  deep  red-brown  by  Fe2Cle, 
the  color  being  discharged  by  EbSO-t.  Nitrous  acid  colors  its  solutions 


458  MANUAL    OF    CHEMISTRY 

bright  green,  and  on  heating  the  mixture,  after  addition  of  a  drop 
of  fuming  nitric  acid,  the  color  changes  to  light -red,  then  to  blood- 
red,  and  finally  a  purple  oil  is  deposited.  Addition  of  a  drop  of 
fuming  nitric  acid  to  cold,  concentrated  solution  of  antipyrin  causes 
precipitation  of  small,  green  crystals.  Antipyrin  is  strongly  basic, 
and  some  of  its  salts  are  used  in  medicine:  Salipyrin  is  antipyrin 
salicylate.  It  is  formed  by  the  action  of  the  acid  and  the  base  upon 
each  other  at  100°  (212°  F.).  It  is  a  white,  crystalline  powder, 
almost  insoluble  in  water. 

Tolypyrin  —  1-toluyl,  2,  3 -dimethyl  pyrazolon  —  is  obtained  in 
the  same  manner  as  antipyrin,  using  p-toluyl-hydrazin  in  place  of 
phenyl-hydrazin,  and  contains  toluyl,  CeHt.CHs  in  place  of  phenyl. 
It  forms  colorless  crystals;  f.  p.  136°  (276.8°  F.) ;  and  has  a  physio- 
logical action  similar  to  that  of  antipyrin.  Its  salicylate  is  preferred 
to  that  of  antipyrin  medicinally. 


SIX    MEMBERED    RINGS. 

Six  membered  heterocyclic  compounds  are  known,  containing 
oxygen,  sulfur  and  nitrogen  in  the  nucleus: 

H  H2  H  H2 

C  C  C  C  N 

S   \  /   \  X\  /  \  /   \ 

HC  CH  HC  C.CH3  HC  CH  H2C  CH2        HC  CH 

I  II  II  II  II  I  II  II  I 

OC          CH        HC  CH  HC          CH        H2C  CH2        HC  CH 

\  /          \  /  vx          \  /          \  s 

OS  N  N  N 

H 
o-pyrone.       /3-Methylpenthiophene.  Pyridin.  Piperidin.  Pyrazin. 

The  oxygen  and  sulfur  compounds  are  neither  numerous  nor  im- 
portant. Some  of  the  former  are  products  of  condensation  of  ali- 
phatic compounds,  8-lactones  and  8-anhydrids  (p.  320). 

Pyrone  (y) — Pyrocomane — O^CHZCH/CO — is  an  oxidized  deriva- 
tive of  7  furane,  produced  from  comenic  acid  by  the  action  of  heat 
and  constituting  the  nucleus  of  comenic,  chelidonic,  and  meconic 
acids. 

Comenic  acid  —  CsHaCMCOOH)  —  is  produced  by  the  action  of 
hot  H2O,  of  dilute  acids,  or  of  bromin  water  upon  meconic  acid.  It 
crystallizes  in  yellowish  prisms,  rather  soluble  in  H2O.  It  is  mono- 
basic. It  is  decomposed  by  heat  into  CC>2  and  pyrone. 

Chelidonic  acid  —  CsH2O2  ( OH )  COOH  —  exists  in  chelidonium , 
in  combination  with  the  alkaloids  sanguinarin  and  chelidonin.  It 
is  a  crystalline  solid,  and  a  dibasic  acid.  Heat  converts  it  into 
comenic  acid,  which  in  turn  yields  pyrone. 


SIX    MEMBERED    HETEEOCYCLIC    RINGS  459 

Meconic  acid  —  CsHCMOH)  (COOH)2 — is  peculiar  to  opium,  in 
which  it  exists  in  combination  with  a  part,  at  least,  of  the  alkaloids. 
It  crystallizes  in  small  prismatic  needles  ;  acid  and  astringent  in 
taste;  loses  its  Aq  at  120°  (248°F.);  quite  soluble  in  water,  soluble 
in  alcohol,  sparingly  soluble  in  ether. 

With  ferric  chlorid  it  forms  a  blood -red  color,  which  is  not  dis- 
charged by  dilute  acids  or  by  mercuric  chlorid;  but  is  discharged 
by  stannous  chlorid  and  by  the  alkaline  hypochlorites. 

Among  the  six-membered  heterocyclic  derivatives  containing  both 
N  and  O,  or  N  and  S  in  the  nucleus  are  a  number  of  important 
dyes:  rosorufin,  naphthol  blue,  Nile  blue,  Lauth's  violet,  toluylene 
red,  safranins,  indulines,  and 

Methylene  blue— (CHshrN^Ha.NS.CeHsrN  i  (CH3)2C1— which 
is  formed  by  oxidation  of  dimethyl -p-phenylene  diamin  in  EbS  solu- 
tion. A  blue  powder,  sparingly  soluble  in  water.  It  is  used  as  a 
dye,  as  a  bacterial  stain,  and  is  administered  as  a  antipyretic  and 
antiperiodic. 

SIX-MEMBERED,    NITROGEN -CONTAINING    RINGS  —  PYRIDIN    AND 
ITS    DERIVATIVES. 

The  pyridin  bases,  closely  related  to  the  vegetable  alkaloids  (p. 
470)  as  well  as  to  some  of  the  basic  substances  formed  during  putre- 
faction, were  first  obtained  from  oil  of  Dippel,  or  bone-oil  (oleum 
animale),  an  oil  produced  during  the  dry  distillation  of  bones,  horns, 
etc.,  and  as  a  by-product  in  the  manufacture  of  ammoniacal  com- 
pounds from  those  sources.  They  also  occur  in  coal-tar,  naphtha, 
commercial  ammonia,  methylic  spirit  and  fusel  oil.  They  are  formed 
synthetically  :  ( 1 )  By  heating  the  aldehyde -ammonias  (p.  360) 
alone,  or  with  aldehydes  or  ketones:  ( 2 )  From  pyrrole  by  the 
action  of  K  or  Na  in  presence  of  methylene  iodid,  etc.  (3)  By 
oxidation  of  hexahydropyridins,  piperidins;  also  by  other  methods. 

The  pyridin  bases  are  colorless  liquids  of  peculiar,  penetrating 
odor.  The  superior  homologues  are  metameric  with  the  anilins. 
They  are  strong  triacid  bases,  and  behave  like  tertiary  monamins. 
Oxidizing  agents  do  not  attack  pyridin,  nor  the  nucleus  of  its  supe- 
rior homologues,  but  the  lateral  chains  of  the  picolins,  etc.,  are 
readily  oxidized,  with  formation  of  carbopyridic  acids.  Reducing 
agents  convert  them  into  piperidins  (p.  461).  They  react  with  sev- 
eral of  the  general  reagents  for  the  alkaloids  (p.  472).  The  two 
most  nearly  characteristic  properties  of  the  pyridin  bases  are:  (1) 
the  formation  of  chloroplatinates  such  as  (CsH^N.HClhPtCU,  which 
on  boiling  with  water,  lose  two  molecules  of  HC1  to  form  "modified 
salts"  such  as  (CsHsNhPtCU  (Anderson's  reaction),  and,  (2)  the 


460  MANUAL    OF    CHEMISTRY 

formation  of  crystalline  addition  products,  alkyl-pyridinium  iodids, 
such  as  CsHsN^i^  on  contact  of  their  alcoholic  solutions  with 
alkyl  iodids. 


/CH  'CH\ 
Pyridin  —  HGQCH'CH^N  —  is  obtained   from   oil   of   Dippel,  or 

from  piperidin.  It  boils  at  115°  (239°  F.),  mixes  with  water  in  all 
proportions,  is  strongly  alkaline  in  reaction.  Its  hydrochlorid  is 
crystalline,  but  deliquescent.  Its  chloroplatinate  fuses  at  240°  (464° 
F.).  When  reduced  by  sodium  and  alcohol,  it  forms  piperidin,  or 
hexahydropyridin  ;  and  when  reduced  by  hydriodic  acid,  normal 
pentane,  CH3.CH2.CH2.CH2.CH3. 

Pyridin  Homologues  —  Alkyl  Pyridins  —  are  substitution  prod- 
ucts containing  alkyl  groups  for  H.  Owing  to  the  inequality  in 
value  of  the  several  C  atoms  of  pyridin  (p.  454),  the  number  of 
substituted  derivatives  is  greater  than  with  benzene.  There  are  three 
monosubstituted  derivatives,  six  each  of  the  bi-  and  tri-  substituted, 
three  tetra-,  and  one  penta-  substituted. 

Methyl-pyridins  —  Picolins  —  C5H4N(CH3)  —  The  three  picolins, 
a,  /3  and  7,  exist  in  oil  of  Dippel,  and  have  been  formed  synthetically. 
Their  b.  p.'s  are  130°,  143°,  and  144°. 

Lutidins  —  Three  ethyl  pyridins,  CsEUN^Hs),  are  known,  a? 
b.p.  148°;  0,  b.p.  166°;  and  7,  b.p.  165°.  Of  the  six  possible 
dimethyl  -  pyridins,  CsHaNCCHsh,  four  are  known,  three  of  which 
exist  in  bone  oil. 

Collidins  —  CgHuN  —  There  are  twenty  -two  possible  collidins,  of 
which  twelve  are  known.  Of  these  several  are  products  of  decom- 
position of  vegetable  alkaloids,  or  exist  in  oil  of  Dippel,  or  are  pro- 
duced during  putrefaction.  Conyrin,  a  basic  substance  produced  by 
boiling  conim  (p.  472)  with  ZnCl2,  is  a-propyl-pyridin.  /s-propyl- 
pyridin  is  produced  from  nicotin  by  passing  its  vapor  through  a 
red-hot  tube.  Aldehydin  is  1,  4-methyl-ethyl-pyridin,  formed  by 
heating  aldehyde  -ammonia  in  alcoholic  solution  to  120°  (248°  F.), 
and  from  other  aldehyde  compounds;  and  exists  also  in  the  products 
of  rectification  of  alcohol.  An  oily  ptomain  produced  during  putre- 
faction of  gelatin  in  presence  of  pancreas  is  a  collidin  of  undetermined 
constitution. 

Parvolins  —  CgHiaN.  —  Theory  indicates  the  existence  of  57  par- 
volins,  of  which  five  are  known.  One  of  these  is  a  ptomain,  produced 
during  putrefaction  of  mackerel  and  of  horse-flesh.  It  is  an  oily 
substance,  slightly  soluble  in  water,  having,  when  fresh,  the  odor  of 
hawthorn  -blossoms,  but  becoming  brown  and  resinous  on  exposure 
to  air. 

Coridins  —  CioHi5N.  —  One  of  the  coridins  has  been  obtained  as 
a  product  of  putrefaction  of  fibrin  and  of  jellyfish  during  several 


SIX    MEMBERED    HETEROCYCLIC    RINGS  461 

months.  It  is  an  alkaline  oil,  which  has  a  poisonous  action  similar 
to  that  of  curari.  The  pyridin  bases  in  general  exert  a  paralyzing 
action  upon  the  central,  and  to  a  less  degree  upon  the  peripheral 
nervous  system.  They  are  the  antagonists  of  strychnin. 

Besides  the  alkyl-pyridins  a  number  of  phenyl-pyridins  (p.  469) 
and  pyridins  containing  unsaturated  lateral  chains,  such  as  vinyl- 
pyridin,  CsH^N^Hs),  are  known. 

Pyridin  Carboxylic  Acids.  —  These  acids,  which  bear  the  same 
relation  to  pyridin  that  the  benzoic,  phthalic,  etc.,  acids  bear  to 
benzene,  are  formed  by  oxidation  of  the  alkyl-pyridins.  As  most  of 
the  alkaloids  contain  pyridin  nuclei  with  lateral  chains,  they  yield 
pyridin  -carboxylic  acids  upon  sufficient  oxidation.  Thus  pyridin- 
/3-monocarboxylic  acid,  or  /3-picolinic  acid,  C5H4N(COOH)(2),  is  nico- 
tinic  acid,  formed  by  oxidation  of  nicotin,  of  pilocarpin,  as  well  as 
of  /3-picolin.  The  «  acid  is  formed  by  oxidation  of  «-picolin.  The 
7  acid,  isonicotinic  acid,  is  formed  by  oxidation  of  3-picolin,  and  of 
many  of  its  derivatives.  Pyridin-  1,  2-dicarboxylic  acid,  CoH3N- 
(COOH)3{i,2),  is  quinolinic  acid,  formed  by  oxidation  of  quinolin, 
and  pyridin  -2,  3-dicarboxylic  acid  is  cinchomeronic  acid,  formed 
by  oxidation  of  cinchonin,  cinchonidin  and  quinin. 

Hydropyridins  —  Piperidins  —  are  compounds  produced  from  the 
pyridins  by  the  action  of  nascent  hydrogen.  Dihydropyridins  and 
tetrahydropyridins  are  known,  the  latter  known  as  piperideins,  but 
by  far  the  most  important  of  the  group  is 

Piperidin  —  Hexahydropyridin  —  H2C  xcH^CHs/  NH  ~  which  is 
produced  by  saponification  of  piperin  (p.  474)  by  heating  with  alco- 
holic KHO,  and  is  also  formed  by  reduction  of  pyridin,  or  by  heating 
pentamethylene-diamin  hydrochlorid.  It  is  a  colorless  liquid;  b.  p. 
106°  (222.8°  F.);  having  an  odor  like  that  of  pepper;  readily 
soluble  in  water  and  in  alcohol.  Oxidizing  agents  rupture  the 
piperidin  ring,  with  formation  of  aliphatic  compounds.  When  heated 
with  methyl  iodid  is  converted  into  methylpiperidin  hydroiodid, 


\CH3  • 

Piperidin  and  methyl  -piperidin  are  particularly  of  interest  as 
being  the  nuclei  of  a  number  of  vegetable  alkaloids.  Thus  coniin  is 
apropyl-piperidin,  and  tropin  and  ecgonin,  the  basic  nuclei  of  the 
atropic  and  cocain  alkaloids,  are  derivatives  of  methyl  -piperidin 
(see  pp.  475,  477). 

Di-,  tri-,  and  tetrazins  —  are  substances  containing  two,  three, 
and  four  N  atoms  in  the  benzene  ring.  There  are  three  diazins, 
three  triazins,  and  three  tetrazins,  o-,  m-,  and  p-,  as  the  nitrogen 
atoms  are  placed  in  adjacent,  symmetrical  or  unsymmetrical  positions. 
Each  of  these  forms  a  series  of  substituted  derivatives. 


462  MANUAL    OF    CHEMISTRY 

N.CH:CH 
Ortho-diazin  —  Pyridazin  —  II         I    ,  Meta-diazin—  Pyrimidin— 

N.CH:CH 
N.CH:CH  CH.N.CH 

I    ,  and   Para-diazin  —  Pyrazin  —  II      I  II      are   known.      The 
CH.N:CH  CH.N.CH 

last-named  is  formed  by  oxidation  of  amido-acetaldehyde  by  distillation 

CH.N.CH 

with  mercuric  chlorid  solution  :  2CHO.CH2.NH2+O=  II  I  II  +  3H2O. 

CH.N.CH 

It  is  also  formed  by  heating  piperazin  with  zinc  dust.  Pyrazin  and 
its  homologues  are  produced  during  fermentation,  and  exist  in  fusel- 
oils,  and  in  commercial  amylic  alcohol.  It  is  a  solid;  f  .  p.  55°; 
b.  p.  115°;  has  the  odor  of  heliotrope,  and  is  strongly  basic. 

The  three  diazins  form  condensation  products  with  benzene:  the 
CH:CH 


benzorthodiazins,    I  /C6H4,  cinnolin,  and  II        /CeH4,  phthal- 


X 
/ 

N        —  N  N.CH 

azin,  and  benzometadiazins,  and  benzoparadiazins. 

CH2.NH.CH2 
Hexahydro-pyrazin  —  Piperazin  —  Diethylene  Diamin  —  I 

CH2.NH.CH2 

—  may  be  obtained  by  reduction  of  para-diazin,  but  is  manufactured 
from  diphenyi-diethylene  diamin,  CeHs.N^cH^CHa/N-^Hs,  which  is 

obtained  by  the  action  of  ethylene  bromid  upon  anilin.  It  crystallizes 
in  colorless  needles;  f  .  p.  104°;  b.  p.  145°;  soluble  in  water,  and 
deliquescent.  It  is  strongly  alkaline  and  basic,  and  absorbs  carbon 
dioxid  from  air.  It  forms  a  soluble  compound  with  uric  acid  (p.  355)  , 
and  is  used  medicinally  as  a  solvent  for  uric  acid  in  lithiasis. 

HN.CO.NH 
Urazin  —  Diurea  —    I         I    —  is  the  diketonic  derivative  of  sym- 

metrical tetrazin  (p.  353). 


B.  CONDENSED  HETEROCYCLIC  COMPOUNDS. 

These  compounds,  which  are  more  numerous  than  the  correspond- 
ing carbocyclic  compounds  (p.  438),  may  be  considered  as  being 
derived  from  the  latter  by  substitution  of  N  for  methine,  =CH— , 
or  of  O,  S,  or  NH  in  a  bivalent  position,  or,  as  in  the  case  of 
iso-indole  (p.  463),  by  substitution  and  modification  of  internal  link- 
age. The  number  of  these  substances  is  still  further  increased  by 
the  existence  of  four  ringed-compounds,  such  as  the  anthraquinolins 
and  indigo-blue  (p.  466).  The  formulas  on  the  following  page  are 
those  of  some  of  the  nitrogen  derivatives,  in  which  indole  and  isoindole 
may  be  considered  as  derived  from  indene  (p.  438) :  carbazole  from 
fluorene;  quinolin,  iso-quinolin  and  naphthydrin  from  naphthalene: 


CONDENSED  HETEROCYCLIC  NUCLEI 


463 


acridin  and  the  anthrapyridins  from  anthracene;   and  phenanthridin 
from  phenanthrene : 


HC3         C  -  CHjS 

I    Bz.    ||  Py.  || 
HC2        .C          CHa 

\1/    \    / 

C  Nn 

H          H 

Benzo-pyrrole. 

(Indole). 


H 
C 

X   \ 

HC           C  CHa 

1             II           1 
HC           C          N 

\   /"\  X 

C           C 
H           H 

Iso-indole. 

] 

< 

HC 

HC 

\ 

< 

J 

C 


\ 


H 
C 


H 

Cy 


HC3         C  CH/3 

I    Bz.    ||    Py.    | 
HC2          C  CHa 


H 
C 


HC 

I 
HC 


\ 


CH 

I 
N 


C  CH 

II  I 

C          CH 

N          C 
H          H 

Diphenylene-imid. 
(Carbazole). 

H          H 
C  C 

HC          C          CH 

I  II  I 

HC  C  CH 

\ 


C           N 

C             C 

N          N 

H 

H           H 

Benzo-pyridin. 

Iso-quinolin. 

Naphthydrin. 

(Quinolin). 

H 

H          H                                   H          H          H 

C 

C          C                                   C          C          C 

S    \    / 

'  \  X.N                     X  \  / 

\    /    \> 

HC           C 

C          CH                HC          C 

C          CH 

1            II 

II            1                        1            II 

II            1 

HC           C 

C           CH                 HC           C 

C          N 

S  /  v 

JX  \  X                    \  X  \ 

X  \  X 

c 

N          C                                  C           C           C' 

H 

H                                  H          H          H 

Acridin.                                                      a-Anthrapyridin. 

H          H 

H                                   H    H 

H    H 

C           C 

C                                    C=C 

C=C 

x  \  / 

\  /  \               /     \ 

/         \ 

HC          C 

C          CH                 HC                 C—  C                 CH 

1            II 

II        1                   \  -    X 

\        X 

HC           C 

C           CH                           C—  C 

c-c 

\  /  \L 

/  \  X                                H      \ 

/      H 

c        c 

N                                              N=C 

H          H 

H 

/3-Anthrapyridin.                                                     Phenanthridin. 

CONDENSED    NUCLEI    CONTAINING    OXYGEN    OR    SULFUR 

MEMBERS. 

Of  these  we  will  consider  only  a  few  of  the  oxygen  compounds: 
Coumarone  —  Benzofurfurane — (formula  p.  464) — is  formed  by 

the  action  of  KHO  upon  the  coumarins,  and  is  the  parent  substance 

of  two  series  of  substitution  derivatives,  «  and  /8. 

Coumarin,  and  isocoumarin  and  their  alkyl  and  phenolic  deriva- 


464  MANUAL    OF    CHEMISTRY 

tives,  e.g.  umbelliferone,  aesculetin,  daphnetin,  hesperetin,  exist  in 
different  vegetables  (pp.  410,  413) .  Coumarin  is  the  odorous  principle 
of  Tonka  beans,  and  also  exists  in  a  variety  of  other  vegetables.  It  is 
formed  by  the  action  of  acetic  anhydrid  and  sodium  acetate  upon 
salicylic  aldehyde.  It  forms  crystalline  needles;  f.p.  67°;  soluble  in 
water,  alcohol  and  ether.  Coumarin  and  isocoumarin  are  benzo- 
derivatives  of  a-pyrone  (p.  458): 

H  H          H  H         H 

C  C          C  C          C 

S  \  S  \  S'\  /  \  /  \ 

HC  C CH  HC  C  CH  HC  C  CH 

I  II  II  I  II  I  I  II  I 

HC  C          CH  HC  C  CO  HC  C  O 

\  /  \   /  \   /  \   /  \  /  \  / 

CO                            CO  C  C 

H                                        H  HO 

Coumarone.                                 Coumarin.  Iso-coumarin. 

Benzo-  and  dibenzo-7-pyrones,  the  latter  called  xanthones,  exist 
in  several  natural  yellow  dyes  of  vegetable  origin,  as  from  quercetin 
and  chrysin  (p.  413). 


CONDENSED    NUCLEI    CONTAINING    A    NITROGEN    MEMBER. 
BENZOPYRROLE    AND    ITS    DERIVATIVES  —  INDIGO    COMPOUNDS. 

Indole — Benzopyrrole — (formula  p.  463) — is  produced:  (1)  by 
distilling  oxindole  over  zinc -dust;  (2)  by  heating  o-nitro-cinnamic 
acid  (p.  403)  with  potash  and  iron  filings,  or  by  similar  reduction 
of  other  unsaturated  o-nitro  substitution  products  of  benzene  (3) 
by  the  interaction  of  calcium  formate  and  phenylglycocoll  (p. 
424) .  It  is  one  of  the  products  of  putrefaction  of  the  proteins  by 
anaerobic  bacteria,  and  is  formed  in  the  intestine  during  pancreatic 
digestion  of  those  substances.  It  is  partly  eliminated  with  the  faeces 
and  partly  reabsorbed,  appearing  in  the  urine  in  su If ocon jugate  com- 
bination. It  crystallizes  in  large,  shining,  colorless  plates,  having 
the  disagreeable  odor  of  naphthylamin.  It  is  a  weak  base,  and  its 
salts  are  decomposed  by  boiling  water.  Its  aqueous  solution,  acidu- 
lated with  HC1,  is  colored  rose -red  by  KNO2.  By  fusion  with  KHO 
it  yields  anilin.  It  gives  the  "pine-shaving  reaction"  (p.  455).  It 
forms  a  compound,  crystallizing  in  red  needles,  with  picric  acid. 

Indole  Homologues  —  Derivatives  of  indole  are  produced  by 
substitution  either  in  the  benzene  or  in  the  pyrrole  ring.  The  posi- 
tions are  distinguished  as  Bz.  1,  2,  3,  4  and  Py.w,  «,  and  ft  (see 
formula  p.  463).  The  alkyl  indoles,  the  superior  homologues  of 
indole,  are  formed:  (1)  by  heating  anilin  with  compounds  containing 
the  group  CO.CH2C1.  Thus  chloracetone  and  anilin  yield  «- methyl- 


CONDENSED    HETEROCYCLIC    COMPOUNDS  465 


indole  : 

(2)  by  heating  the  phenylhydrazones  (p.  429)  of  the  ketones,  alde- 
hydes or  ketone  acids  with  ZnCl2.  Thus  w,  a-dimethylindole  is 
obtained  from  acetone  -  phenyl-  methyl  -  hydrazone  : 


The  best  known  alkyl  indoles  are  those  in  which  the  alkyl  group 
is  in  the  pyrrole  ring.  They  dissolve  in  concentrated  acids,  and  are 
precipitated  unaltered  from  the  solutions  by  dilution  with  water. 
Fused  with  KHO,  they  yield  potassium  salts  of  indole-  carboxylic 
acids.  Their  hydrogen  may  be  replaced  by  acidyls  or  by  the  diazo 
group.  They  give  the  "pine-shaving  reaction,"  and  form  red, 
crystalline  compounds  with  picric  acid. 

)8-Methyl-indole—  Skatole  —  CeH^H^^CH—  exists  in  fa>ces, 

in  which  it  exceeds  the  indole  in  amount.  It  is  formed  during  putre- 
faction of  the  proteins,  or  by  the  action  upon  them  of  KHO  in 
fusion;  also  by  the  reduction  of  indigo.  It  is  best  obtained  syntheti- 
cally by  heating  propidene  -  phenylhydrazone  with  zinc  chlorid  : 

C6H5.NH.N:CH.CH2.CH3  =  C6H4<N(H^)CH+NH3.  It  crystallizes 
in  brilliant  plates;  f.p.  95°  (203°  F.);  insoluble  in  water,  soluble  in 
alcohol  and  in  ether;  distils  with  vapor  of  water;  has  a  strong  faecal 
odor.  Its  solution  in  concentrated  HC1  is  violet.  Its  H2SO4  solution 
is  colored  deep  purple  when  heated.  Skatole,  like  indole,  is  in  part 
reabsorbed  from  the  intestine,  and  appears  in  the  urine,  combined 
with  sulfuric  and  glucuronic  acids. 

/3-Methyl-indole-a-carboxylic  Acid—  CeH^NH5!^0-00011—  f-P- 
165°;  is  a  product  of  putrefaction,  and  also  occurs  in  normal  urine. 
It  produces  an  intense  violet  color  with  HC1  and  dilute  Fe2Cle  solu- 

tion. Skatole-acetic  acid—  C3H4^NH^^C-CH2.COOH—  is  also  pro- 
duced during  putrefaction. 

Iso-indole  —  (formula,  p.  463)  —  is  formed  by  the  action  of  alco- 
holic ammonia  upon  brom-acetophenone  (p.  400).  It  crystallizes  in 
colorless,  silky  plates;  f.  p.  195°;  insoluble  in  water,  soluble  in 
alcohol,  ether  and  benzene. 

Indoxyl  —  £-  Oxy  indole  —  C6H4  <^HJ^  CH  -—  not  to  be  con' 
founded  with  oxindole  (p.  466),  is  a  phenolic  derivative  of  indole, 
obtained  from  indigo  -blue  by  fusion  with  KHO  without  contact  of 
air;  or  from  its  a  -carboxylic  acid,  indoxylic  acid.  It  is  a  very 
unstable,  oily  substance,  soluble  in  water,  and  readily  oxidized  to 
indigo-blue  (below).  It  readily  combines  with  sulfuric  acid  or  the 


sulfates  to  form  indoxyl-sulfuric  acid,  C6H4<T  ;  ^    \      ,  which  is 


C—  O—  S:02 

;  ^    \ 

NH  —  CH  OH 


30 


466  MANUAL    OF    CHEMISTRY 

the  uroxanthm,  or  urinary  indican,  existing  in  the  urine,  and  formed 
from  indole.  Acids  decompose  it,  with  formation  of  indoxyl,  which 
is  converted  into  indigo -blue  by  Fe2Cle  (see  Urine). 

Oxindole  —  CcH^^n/CO —  ^e  lactam  of  o-amido-phenyl  acetic 
acid  (p.  424),  is  obtained  from  dioxindole  by  reduction  with  sodium 
amalgam  in  acid  solution;  or  by  reduction  of  o-nitrophenyl- acetic 
acid.  It  crystallizes  in  easily  soluble,  colorless  needles;  f .  p.  120°. 
In  moist  air  it  oxidizes  to  dioxindole.  It  reduces  ammoniacal  silver 
nitrate  solution.  It  combines  with  acids  and  bases. 

Dioxindole— Hydrindic  Acid—  CeE^^^^^CO—  is  the  lactam 

o-amido-mandelic  acid  (p.  424),  and  is  formed  by  the  action  of  Na 
on  isatin  suspended  in  water.  It  forms  yellow  prisms,  soluble  in 
water,  and  combines  with  acids  and  bases. 

Isatin  —  C6H4\^g/CO — the  lactam  of  o-amido-benzoyl- formic 
acid  (p.  424),  is  formed  by  oxidation  of  indigo -blue  by  HNOs;  by 
oxidation  of  oxindole  or  of  dioxindole;  and  by  other  methods.  It  crys- 
tallizes in  shining,  transparent,  red-brown  prisms,  odorless,  sparingly 
soluble  in  water,  readily  soluble  in  alcohol.  On  further  oxidation  it 

/CO 
yields  isatoic  acid,  CeH^  I.  .    With  hydroxylamin  it  forms  isa- 

N.COOH 
yC=NOH 
toxim,  CeH^  .\        ,  which  is  also  formed  by  the  action  of  nitrous 

JN  -^—  OvyJti. 

acid  upon  oxindole. 

Indigo  -  blue —Indigotin—C6H4^NH/c :  C\NH/C6H4—  constitutes 
the  greater  part  of  commercial  indigo.  It  does  not  exist  preformed 
in  nature,  but  many  plants,  particularly  Indigotifera  tinctoria  and 
Isatis  tinctoria,  contain  a  yellow  glucosid,  indican  (p.  413),  which 
on  heating  with  dilate  acids,  or  probably  by  enzymic  action  on  ex- 
posure to  air  in  presence  of  water,  is  decomposed  into  a  sugar  and 
indigo -blue.  Commercial  indigo  contains  20  to  90  per  cent,  of 
indigo-blue,  which  may  be  separated,  nearly  pure,  by  cautious  sub- 
limation. It  is  formed  in  several  reactions,  e.g.,  by  oxidation  of 
indoxyl  by  Fe2Cle  and  HC1;  from  o-nitro-cinnamic  acid  by  two 
methods;  by  fusing  phenyl-glycocoll  (p.  424)  with  KHO;  or  by 
heating  o-nitro-acetophenone  (p.  400)  with  zinc  dust.  It  forms 
purple -red,  metallic,  shining  prisms  or  plates,  odorless,  tasteless, 
neutral,  soluble  in  hot  anilin,  hot  oil  of  turpentine,  and  melted 
paraffin,  insoluble  in  the  usual  solvents.  When  heated  it  is  in 
part  converted  into  a  dark  red  vapor,  and  partly  decomposed  into 
anilin  and  other  products.  In  the  presence  of  aqueous  alkaline 
solutions,  reducing  agents  convert  indigo-blue  into  indigo-white, 

or  di-indoxyl,  CoR^^C— c££^C6H4,  which  dissolves  in  the 


CONDENSED    HETEROCYCLIC    COMPOUNDS  467 

alkali.  This  substance  absorbs  oxygen  from  the  air  rapidly,  with 
regeneration  of  indigo -blue.  In  absence  of  air  it  may  be  precipitated 
from  its  alkaline  solution  by  HC1,  as  a  white,  crystalline  powder, 
insoluble  in  water,  but  soluble  in  alcohol  and  ether,  forming  yellow 
solutions.  When  oxidized,  as  by  warming  with  dilute  HNOa,  indigo- 
blue  is  converted  into  isatin,  whose  dilute  solutions  are  also  yellow. 
Hence  the  decoloration  of  indigo -blue  solution  is  utilized  as  a  test 
both  for  oxidizing  (HNOa)  and  for  reducing  ( Mulder -Neubauer  test 
for  glucose)  substances. 

Indigo-sulfonic  Acids.  —  Indigo -blue  dissolves  slowly  in  concen- 
trated sulfuric  acid,  to  a  green  solution,  from  which  water  precipitates 
a  blue  powder,  soluble  in  water,  but  insoluble  in  dilute  acids.  This 
is  indigo-monosulfonic  or  phoenicin-sulfonic  acid,  CieHg^C^.SOsH, 
which  forms  purple-red  salts,  soluble  in  water.  With  fuming  (Nord- 
hausen)  sulfuric  acid,  indigo-disulfonic,  sulfindylic,  or  sulfindigotic 
acid,  CieHg^CMSOsHh,  is  formed,  whose  K  and  Na  salts  are  also 
soluble  in  water,  and  are  met  with  in  commerce  as  pastes  called 
indigo-carmine. 

Dibenzo-pyrrole — Diphenyl-imid — Carbazole — (formula  p.  463)  — 
exists  in  crude  anthracene,  and  is  formed  by  passing  diphenylamin 
through  a  red-hot  tube,  and  from  other  diphenyl  derivatives.  It 
is  a  crystalline  solid;  f .  p.  238°;  soluble  in  alcohol  and  in  toluene. 
It  is  a  weak  base,  gives  the  pine -shaving  reaction,  and  the  blue  color 
with  isatin  and  H.2S04,  and  forms  a  picrate  fusible  at  182°. 


QUINOLIN    AND    ISO-QUINOLIN    AND    THEIR    DERIVATIVES. 

The  quinolin,  or  benzo-pyridin  bases  accompany  the  pyridin 
bases  (p.  459)  in  bone-oil,  and  like  those  substances,  are  closely 
related  to  the  vegetable  alkaloids.  Quinolin,  the  parent  substance  of 
the  group,  was  first  obtained  by  distilling  quinin  and  cinchonin  with 
lime. 

Chemically  the  quinolins  are  also  related  to  the  naphthalenes 
(p.  452),  and  are  formed  by  similar  synthetic  methods.  Thus 
quinolin  is  formed  from  allyl-anilin  :  C6H5.NH.CH2.CH:CH2  = 

C6H4\cH:CH+2H2'  in  tne  same  manner  as  naphthalene  is  formed 
from  phenyl-butylene  (p.  440).  Quinolin  and  its  derivatives  may 
also  be  produced  synthetically  :  (1)  From  o-amido-benzenic  com- 
pounds containing  an  oxygen  atom  in  the  second  lateral  chain. 
Thus  o-amido-benzoic  aldehyde  and  acetone  yield  a-methyl-  quinolin: 


N     l          .  +  2HiO.   (2)  By  heat- 
ing the  anilins  with  glycerol  and  H2SO4,  in  presence  of  an  oxidizing 


I 
468  MANUAL    OF    CHEMISTRY 

agent,  such  as  nitro-benzene  :    C6H5.NH2H-CH2OH.CHOH.CH2OH= 

,CH:CH 

C6H/         I    +3H2O+H2.     (3)    By   the   action   of    aldehydes   upon 
N    iCH 

anilins  in  presence  of  H2SO4  or  HC1.     Thus  a-  methyl  -quinolin  is  ob- 
tained from  anilin  and  acetic   aldehyde  :    C6H5.NH2-h2CHO.CH3= 
,CH:CH 


The  quinolin  bases  are  liquids  of  penetrating  odor,  sparingly  sol- 
uble in  water,  readily  soluble  in  alcohol  and  in  ether.  They  are 
strong  triacid  bases,  and  form  salts  and  ammonium-like  compounds. 
/CH:CH 

Quinolin—  C6H4\        I    —is  a  mobile  liquid  ;   b.  p.  238°  (460.4° 

N    iCH 

F.);  becoming  rapidly  brown  on  exposure  to  air;  has  an  intensely 
acrid  and  bitter  taste,  and  an  odor  somewhat  like  that  of  bitter 
almonds;  sparingly  soluble  in  water,  readily  soluble  in  alcohol  and 
ether.  Its  dichromate  crystallizes  in  yellow  needles  ;  f.  p.  165°;  very 
sparingly  soluble  in  water. 

Quinolin  Homologues  —  Quinolin  is  the  nucleus  of  a  vast  number 
of  products  of  substitution,  among  which  are  many  isomeres,  due  to 
differences  in  orientation,  according  as  the  substitution  occurs  in  the 
o-,  m-,  or  p-  position  in  the  benzene  ring,  or  in  the  a,  ft,  or  y  posi- 
tion in  the  pyridin  ring  (see  formula,  p.  463).  Thus  there  are  seven 
methyl-quinolins,  or  lepidins,  etc. 

Quinolin  is  of  medical  interest  chiefly  in  connection  with  the  vege- 
table alkaloids  of  which  it  is  the  nucleus  (p.  478).  Certain  synthetic 
basic  substances  containing  the  quinolin  nucleus  have  also  been  used 
in  medicine,  in  saline  combination,  as  antiperiodics  and  antipyretics. 
Among  these  are  thallin,  ethyl-thallin  and  kairin. 

yCH:CH 

a-Oxyquinolin—  Carbostyril  —  CelLiy         I       —  is    the    lactam    of 

XN    :C.OH 

o-amido-cinnamic  acid,  formed  by  reduction  of  o-nitro-cinnamic  ester. 


Iso-  quinolin  —  CeH  I    —  differs   from    quinolin   in   that   the 

attachment  of  the  benzene  and  the  pyridin  rings  is  by  the  ft  and  7  po- 
sitions of  the  latter  in  iso-  quinolin,  and  by  the  a  and  ft  positions  in 
quinolin  (see  formulae,  p.  463).  It  accompanies  quinolin  in  coal-tar, 
and  is  the  nucleus  of  the  opium  alkaloids  (p.  483).  It  resembles 
quinolin  in  its  properties.  F.  p.  23°;  b.  p.  240.5°. 

Hydroquinolins.  —  Compounds  corresponding  to  dihydroquinolins 
are  known.  Tetrahydroquinolins  are  formed,  by  hydration  of  the 
pyridin  ring,  by  the  action  of  nascent  hydrogen  on  quinolius.  Deca- 
hydroquinolin,  Co  His  N,  corresponding  to  piperidin  (p.  461),  is 
formed  by  heating  quinolin  with  hydriodic  acid  and  phosphorus. 


PHENYL-PYEIDYL,  DIPYRIDYL    COMPOUNDS,  ETC.  469 


C.     PHENYL-PYRIDYL,   DIPYRIDYL,  AND   PYRIDYL- 
PYRROLE   COMPOUNDS. 

These  compounds  (p.  453)  contain  two  nuclei,  one  at  least  hetero- 
cyclic,  united  together  by  loss  of  two  hydrogen  atoms. 

Phenyl-pyridyls,  or  phenyl-pyridins  (p.  461)  consist  of  one  or 
more  phenyl  groups  substituted  in  pyridin,  7-Phenyl-pyridyl, 

N\CH-CH^C~C\CH-CH/CH»  as  wel1  as  the  a  and  P  compounds, 
and  diphenyl-  and  tetraphenyl-pyridins,  are  known. 

y,  y-Dipyridyl-N<^I^>C-C<^z£i>-is  formed  by  the 

action  of  sodium  upon  pyridin.  It  forms  colorless  needles;  f.  p. 
114°;  which  yield  isonicotinic  acid  (p.  461)  on  oxidation.  The  «- ft 
and  ft  -ft  dipyridyls  are  formed  by  oxidation  of  the  phenanthrolins, 
and  both  yield  nicotinic  acid  on  oxidation.  A  fourth,  probably  a -a, 
is  formed  by  passing  vapor  of  pyridin  through  a  red-hot  tube.  The 
dipyridyls  take  up  nascent  hydrogen  to  form  substances,  CioHi4N2, 
isomeric  with  nicotin,  and  resembling  that  alkaloid  (p.  473)  closely 
in  chemical  properties  and  in  physiological  action.  The  one  obtained 
from  ft- ft  dipyridyl  is  a  very  soluble  and  highly  poisonous  liquid, 
called  nicotidin.  That  from  7-7  dipyridyl  is  a  crystalline  solid,  sol- 
uble in  water,  less  actively  poisonous  than  nicotin,  and  called  iso- 
nicotin. 

The  pyridyl-pyrroles  are  formed  by  union  of  a  pyridin  and  a 
pyrrole  ring,  as  the  dipyridins  are  formed  by  union  of  two  pyridin 

yCH=CHv  ^CH— NH 

rings.       a- Pyridin -^-pyrrole,    HC^  iC — C\          I     ,    consti- 

^CH—  N^  XCH=CH 

tutes  the  nucleus  of  nicotin  (p.  474).  It  is  a  crystalline  solid; 
f.  p.  72°. 

ALKALOIDS. 

Until  the  constitution  of  all  the  substances  grouped  under  this 
term  shall  have  been  determined,  the  limitations  of  the  application  of 
the  name  can  be  only  provisional.  It  was  first  applied  to  the  few 
alkali -like  substances  first  obtained  from  vegetable  products,  the 
vegetable  bases  morphin,  narcotin,  veratrin,  strychnin.  Afterwards 
its  application  was  extended,  and  at  the  same  time  made  more  precise, 
to  include  organic,  nitrogenized  substances,  alkaline  in  reaction,  and 
capable  of  combining  with  acids  to  form  salts  in  the  same  way  as  does 
ammonia.  This  limitation  is,  however,  too  broad,  as  it  classes  the 
aliphatic  amins,  and  other  similar  bodies,  with  the  true  alkaloids, 
which  are  cyclic.  All  substances  generally  classed  as  alkaloids,  whose 


470  MANUAL    OF    CHEMISTRY 

constitution  has  been  determined,  contain  at  least  one  nitrogen- 
containing  heterocyclic  ring,  except  theobromin  and  caffein,  which 
are  not  true  alkaloids,  but  purin  bases  (p.  358).  Almost  all  alka- 
loids of  known  constitution  contain  the  pyridin  ring,  more  or  less 
modified  by  hydrogen  at  ion,  either  alone  or  in  quinolin  or  isoquinolin. 
Therefore,  until  recently,  alkaloids  were  considered  to  be:  basic  sub- 
stances containing  the  pyridin  ring.  But  the  hygrins,  alkaloids 
existing  in  coca  leaves,  are  derivatives,  not  of  pyridin,  but  of  pyr- 
rolidin  (p.  456),  a  five-membered  nucleus.  So  far  as  is  now  known, 
no  alkaloid  contains  more  than  one  nitrogen  atom  in  one  and  the  same 
ring.  Therefore,  provisionally,  it  may  be  stated  that  the  alkaloids 
are  basic  substances  derived  from  heterocyclic  nuclei  containing  but 
one  nitrogen  atom  in  each  nucleus.  Under  this  definition  pyridin 
and  quinolin  and  their  homologues  are  alkaloids,  as  well  as  indole, 
and  other  basic  pyrrole  compounds. 

Some  of  the  alkaloids,  nicotin,  conim,  spartem  and  arecolin  are 
liquid,  volatile,  and  contain  C,  N  and  H.  Most  of  them,  to  the  num- 
ber of  more  than  a  hundred,  are  solid,  crystalline,  only  partially 
volatile  without  decomposition,  if  at  all,  and  contain  C,  N,  H  and  O. 
Most  of  the  alkaloids  are  very  sparingly  soluble  in  water,  although 
some  are  readily  soluble;  but  soluble  in  alcohol,  ether,  petroleum- 
ether,  chloroform,  benzene  or  amylic  alcohol.  Their  salts,  on  the 
other  hand,  are,  for  the  most  part,  soluble  in  water,  but  insoluble  in 
the  other  solvents  mentioned,  except  alcohol,  in  which  they  are 
soluble.  They  are  laevogyrous,  except  quinidin,  cinchonin,  conim, 
narcotin  and  pilocarpin,  which  are  dextrogyrous.  Usually  their 
rotary  power  is  diminished  by  combination  with  acids,  although  with 
quinin  the  reverse  is  the  case.  Free  narcotin  is  laevogyrous,  its 
salts  are  dextrogyrous.  Most  of  the  alkaloids  are  bitter  in  taste,  and 
alkaline  in  reaction. 

The  naming  of  the  salts  of  the  alkaloids  has  been  the  subject  of 
no  little  discussion.  In  obedience  to  the  rules  of  orthography 
adopted  (see  Appendix)  the  names  of  the  alkaloids  are  made  to 
terminate  in  in,  although  in  non-chemical  writings  the  termination 
ine  is  still  usual,  and  the  older  termination  ia  is  occasionally  met 
with.  As  most  of  the  alkaloids  are  tertiary  amins  and  some  second- 
ary amins,  they  combine  with  acids  in  the  same  manner  that  ammonia 
does,  that  is,  without  elimination  of  water  or  of  hydrogen,  and  by 
change  of  the  nitrogen  valence  from  trivalent  to  quinquivalent: 


2H3  :  N+H2S04=(H3  1 

Ammonia.        Sulfuric  acid.        Ammonium  sulfate. 

2[(Ci7H1903)  i  N]+H2S04=[(C17H1903)  •  KO 
Morphia.        Sulfnric  acid.        Morphium  sulfate. 


ALKALOIDS  471 

Therefore  these  salts  do  not  contain  morphin,  CnHigOsN'",  as  a  sub- 
stitute for  the  hydrogen  of  the  acid,  but  the  hypothetical  morphium 
(CuH^oOaN^7,  as  the  ammoniacal  salts  are  not  salts  of  ammonia,  NHs, 
but  of  ammonium,  NEU.  The  compounds  formed  by  the  union  of  mor- 
phin and  other  alkaloids  with  the  hydracids,  HC1,  HBr,  HI,  may 
properly  and  conveniently  be  referred  to  as  morphin  hydrochlorid  (not 
hydrochlorate)  hydrobromid,  hydroiodid,  etc.,  they  being  considered, 
not  as  salts  of  those  acids,  but  as  compounds  in  which  one  of  the 
valences  of  the  quinquivalent  nitrogen  atom  is  satisfied  by  hydrogen 
and  another  by  chlorin. 

Many  of  the  alkaloids  behave  like  esters,  and  are  hydrolyzed  by 
baryta  or  the  caustic  alkalies,  or  by  mineral  acids,  into  two  com- 
ponents, one  a  base,  the  other  an  acid,  the  latter  usually  cyclic  and 
nitrogenous.  On  the  other  hand,  concentrated  HC1  removes  EbO 
from  those  alkaloids  containing  more  than  one  hydroxyl,  converting 
them  into  apo-alkaloids,  as  morphin  is  converted  into  apomorphin. 
Other  alkaloids,  containing  methoxyl  groups  (OCHs),  when  acted 
upon  by  concentrated  HC1,  are  modified  by  replacement  of  OH  for 
the  methoxyl  groups.  Reducing  agents  form  hydro -bases,  as  piper- 
idin  is  derived  from  pyridin.  Distillation  with  zinc -dust  causes 
removal  of  the  lateral  chains  from  the  oxygen-containing  alkaloids, 
with  liberation  of  pyridin  or  quinolin.  Oxidizing  agents  form  car- 
boxylic  acids,  or  decompose  the  alkaloid  into  an  acid  and  a  base,  or 
cause  the  union  of  two  molecules  of  the  alkaloid  with  loss  of 
hydrogen . 

Separation  of  Alkaloids  from  Organic  Mixtures. — The  separation 
of  an  alkaloid  from  an  organic  mixture  (contents  of  stomach,  viscera, 
etc.)  in  a  condition  of  puritjr  sufficient  to  permit  of  its  identification, 
is  one  of  the  most  difficult  tasks  of  the  toxicologist,  and  not  to  be 
attempted  in  a  case  liable  to  be  the  subject  of  legal  inquiry  except  by 
one  thoroughly  competent.  The  processes  usually  followed  are  modi- 
fications of  that  originally  used  by  Stas,  of  which  the  most  exhaus- 
tive is  the  method  of  Dragendorff.  They  depend  upon  differences  in 
the  solubilities  of  the  several  alkaloids  and  of  their  salts  in  water  or 
alcohol,  and  in  various  solvents  immiscible  with  water.  The  alkaloid 
is  first  extracted  as  a  tartrate,  sulfate  or  hydrochlorid  by  water  or 
alcohol,  acidulated  with  the  appropriate  acid,  and  the  extract  purified 
to  a  clear,  acid,  watery  solution.  This  acid  solution  is  then  succes- 
sively shaken  with  the  immiscible  solvents,  such  as  ether,  petroleum- 
ether,  benzene,  chloroform,  amylic  alcohol  and  acetic  ether,  the 
solvents  being  separated  from  the  aqueous  solution,  and  each  evap- 
orated by  itself.  During  this  treatment  the  alkaloids  are  held  in  the 
aqueous  solution,  while  the  other  solvents  extract  impurities  and 
certain  glucosidal  and  acid  poisons.  The  watery  solution  is  now 


472  MANUAL    OF    CHEMISTRY 

rendered  alkaline,  which  causes  liberation  of  the  alkaloid  from  its 
saline  combination,  and  is  again  successively  agitated  with  the  im- 
miscible solvents  named,  they  being  each  individually  separated  from 
the  aqueous  liquid  and  evaporated.  Each  solvent  extracts  those 
alkaloids  which  it  is  capable  of  dissolving,  and  they  are  sought  for 
by  the  suitable  tests  in  the  appropriate  residues.  Thus  strychnin  is 
extracted  by  benzene,  and  morphin  by  amylic  alcohol.  The  details 
of  the  process,  which  are  quite  elaborate,  must  be  carefully  observed, 
and  the  student  is  referred  to  special  treatises  upon  the  subject. 

General  Reactions  of  the  Alkaloids.  —  A  great  number  of 
"general  reagents"  for  alkaloids  have  been  suggested,  of  which  only 
the  more  important  can  be  here  mentioned: 

Potash,  soda,  ammonia,  lime,  baryta  and  magnesia  precipitate  the 
alkaloids  from  solutions  of  their  salts. 

Phosphomolybdic  acid  forms  a  precipitate  which  is  bright -yellow 
with  anilin,  morphin,  veratrin,  aconitin,  emetin,  atropin,  hyoscyamin, 
the'in,  theobromin,  coniin  and  nicotin;  brownish -yeUow  with  nar- 
cotin,  code'in,  and  piperin;  yellowish -white  with  quinin,  cinchonin 
and  strychnin;  yolk -yellow  with  brucin  (DeVry's,  or  Sonnenschein's 
reagent) . 

Potassium  iodhydrargyrate  gives  a  yellowish  precipitate  with 
alkaloidal  solutions  which  are  acid,  neutral  or  faintly  alkaline  in 
reaction  (Mayer's  reagent). 

Classification  of  the  Alkaloids. — The  alkaloids  of  known,  or  par- 
tially known  constitution,  can  be  classified  according  to  the  nuclei 
which  they  contain: 

A.  Pyrrole  alkaloids. — The  hy grins  are  the  only  alkaloids  now 
known  of  this  group. 

B.  Pyridin  alkaloids — including  trigonellin,  pilocarpin,  arecolin, 
coniin,   nicotin,    piperin,    the   atropic    alkaloids,   cocam,   pelletierin, 
spartem,  cytisin  and  their  derivatives. 

C.  Quinolin   alkaloids  —  including    the    cinchona    and    strychnos 
alkaloids. 

D.  Isoquinolin  alkaloids — including  the  opium,  hydrastis,  berberis 
and  corydalis  alkaloids. 

E.  Alkaloids  of  undetermined  constitution. 

PYRIDIN  ALKALOIDS. 

Coniin — CgHrzN — is  the  most  simply  constituted  of  the  natural 
vegetable  alkaloids,  and  was  the  first  to  be  produced  synthetically. 
It  exists  in  Conium  maculatum,  in  which  it  is  accompanied  by  two 
other  alkaloids,  methyl-coniin,  CgHieNfCHs),  and  conhydrin,  CgHn 
NO,  the  former  a  volatile  liquid,  the  latter  a  crystalline  solid. 


PYRIDIN    ALKALOIDS  473 

Coniin  is  a  colorless,  oily  liquid;  has  an  acrid  taste  and  a  dis- 
agreeable, penetrating  odor;  sp.  gr.  0.878;  can  be  distilled  when  pro- 
tected from  air;  boils  at  212°  (413. 6°  F.) .  Exposed  to  air  it  resinifies. 
It  is  very  sparingly  soluble  in  water,  but  is  more  soluble  in  cold  than 
in  hot  water;  soluble  in  all  proportions  in  alcohol,  soluble  in  six 
volumes  of  ether,  very  soluble  in  fixed  and  volatile  oils. 

'  Its  vapor  at  ordinary  temperatures  forms  a  white  cloud  when  in 
contact  with  a  glass  rod  moistened  with  HC1,  as  does  NHs.  It  forms 
salts  which  crystallize  with  difficulty.  Chlorin  and  bromin  combine 
with  it  to  form  crystallizable  compounds;  iodin  in  alcoholic  solution 
forms  a  brown  precipitate  in  alcoholic  solutions  of  con i in,  which  is 
soluble  without  color  in  an  excess.  Ethyl  and  methyl  iodids  combine 
with  it  to  form  ethyl-  and  methyl -conim  hydriodids. 

It  has  been  obtained  synthetically  from  a-picolin  by  reactions 
which  show  it  to  be  a-propyl  piperidin.  The  relations  of  pyridin, 
piperidin,  and  conim  are  shown  by  the  following  formulae: 

H  H2  H2 

c  c  c 

/\  /\  /\ 

HO        CH  H2C        CH2  H2C        CH2 

II         I  II  II 

HC        CH  HoC        CH,  H2C        CHC3H7 

\^                                 "    \/  \/ 

N                                          N  N 

H  H 

Pyridin.                                       Piperidin.  Coniin. 

ANALYTICAL  CHARACTERS. — (1.)  With  dry  HC1  gas  it  turns  red- 
dish-purple, and  then  dark-blue.  (2)  Aqueous  HC1  of  sp.  gr.  1.12 
evaporated  from  conim  leaves  a  green -blue,  crystalline  mass.  (3) 
With  iodic  acid:  a  white  ppt.  from  alcoholic  solutions.  (4)  With 
H2S04  and  evaporation  of  the  acid:  a  red  color,  changing  to  green, 
and  an  odor  of  butyric  acid.  (5)  When  mixed  with  commercial 
nitrobenzene  a  fine  blue  color  is  produced,  changing  to  red  and 
yellow. 

Paraconiin — CsHisN — is  a  synthetical  product  closely  resembling 
conim,  obtained  by  first  allowing  butyric  aldehyde  and  an  alcoholic 
solution  of  ammonia  to  remain  some  months  in  contact  at  30° 
(86°  F.),  when  dibutyraldin  is  formed:  2(C4H8O)-fNH3=C8Hi7NO+ 
H20.  The  dibutyraldin  thus  obtained  is  then  heated  under  pressure 
to  150°-180°  (302°-356°  F.),  when  it  loses  water,  and  forms  para- 
coni'in:  CgHnNC^CgHisN+EbO.  A  synthesis  which,  in  connection 
with  the  decompositions  of  paraconii'n,  shows  its  rational  formula  to 
be  (C*>'*)N. 

Nicotin — CioHi4N2 — exists  in  tobacco  in  the  proportion  of  2-8  per 
cent.  It  is  a  colorless,  oily  liquid,  which  turns  brown  on  exposure 


474  MANUAL    OF    CHEMISTRY 

to  air,  has  a  burning,  caustic  taste,  and  a  disagreeable,  penetrating 
odor.  It  distils  at  250°  (392°  F.)  ;  burns  with  a  luminous  flame;  sp. 
gr.  1.027  at  15°  (59°  F.);  is  very  soluble  in  water,  alcohol,  the  fatty 
oils,  and  ether.  The  last-named  fluid  removes  it  from  its  aqueous 
solution  when  the  two  are  shaken  together.  It  absorbs  water  rapidly 
from  moist  air.  Its  salts  are  deliquescent,  and  crystallize  with 
difficulty. 

The  oxidation  of  nicotin  produces  nicotinic,  or  ft  monocarbopyridic, 
acid  (p.  461).  When  distilled  with  zinc  chlorid  and  lime  it  yields 
pyrrole,  ammonia,  methylamin,  hydrogen,  and  pyridin  bases.  When 
heated  to  250°  (482°  F.)  it  yields  a  collidin  along  with  other  products. 
By  limited  oxidation  it  produces  a  substance,  CioHioN2,  formerly 
considered  as  isodipyridin,  but  shown  to  be  ft-  pyridin-  n-methyl-a- 
pyrrole, 

/CH=CH,  CH     -CH 


N(CH3)CH 
of  which  nicotin  is  the  tetrahydro,  or  pyrrolidin  derivative  — 


\          i  • 

XN(CH3)-CH2 


ANALYTICAL  CHARACTERS.  —  (1)  Its  ethereal  solution,  added  to 
an  ethereal  solution  of  iodin,  separates  a  reddish  -brown,  resinoid  oil, 
which  gradually  becomes  crystalline.  (2)  With  HC1,  a  violet  color. 
(3)  With  HNOs,  an  orange  color. 

TOXICOLOGY.—  Nicotin  is  a  very  active  poison.  The  free  alkaloid 
is  probably  capable  of  causing  death  in  doses  of  two  to  three  drops. 
It  was  the  first  alkaloid  to  be  separated  from  the  cadaver  in  a  case  of 
homicide.  Most  cases  of  poisoning  from  nicotin  are  due  to  tobacco, 
frequently  resulting  from  its  use  in  enemata.  When  administered  to 
dogs  in  doses  of  two  to  four  drops,  its  effects  begin  within  half  a 
minute  to  two  minutes,  and  death  ensues  within  one  to  five  minutes. 
In  the  human  subject  tobacco  or  its  decoction  causes  nausea,  vertigo, 
dilatation  of  the  pupils,  vomiting,  syncope,  diminution  of  the  rapidity 
and  force  of  the  heart.  With  large  doses  there  are  no  subjective 
symptoms,  the  victim  falls  unconscious  instantly,  and  dies  within  five 
minutes,  without  convulsions,  and  with  very  few  or  only  one  deep 
sighing  respiratory  act. 

Piperin  —  CnHigNOs  —  an  alkaloid  occurring  in  black  and  white 
pepper,  and  isomeric  with  morphin,  crystallizes  in  large  prisms;  f.  p. 
128°;  almost  insoluble  in  water,  readily  soluble  in  alcohol  and  in 
ether.  It  is  a  weak  base,  without  alkaline  reaction,  and  only  form- 
ing very  unstable  salts  with  concentrated  acids.  It  is  one  of  the 


PYRIDIN    ALKALOIDS  475 

alkaloids  whose  complete  synthesis  has  been  accomplished,  and  is  one 
of  the  "ester -alkaloids"  most  directly  derived  from  pyridin.  When 
piperin  is  heated  with  alcoholic  soda,  it  is  hydrolysed  into  piperic 
acid,  Ci2HioO4  (p.  403),  and  piperidin.  It  is  therefore  piperidin 
piperate,  or  piperidin  3,  4-methylene-dioxy-cinnamyl-acrylate: 


H  , 
C 

HC           CH 

1!          1 
HC           CH 

V 

H2 
C 

H2C           CH2 
1             1 
H2C           CH2 

V 

1 

H2 
C 

H2C           CH2 
1            1 
H2C           CH2 

V 

1 

CO.CH:CH.CH:CH 

Pyridin.  Piperidin.  Piperin. 

Atropin— Atropina  (U.  S.)  —  Atropia  (Br.)— Ci7H23NO3.— Bella- 
donna, stramonium,  hyoscyamus,  and  dubosia  contain  four  alkaloids: 
Atropin,  hyoscyamin,  hyoscin,  and  lelladonin.  The  first  two  are 
isomeric  with  each  other,  and  possibly  identical. 

Atropin  forms  colorless,  silky  needles,  which  are  sparingly  soluble 
in  cold  water,  more  readily  soluble  in  hot  water,  very  soluble  in  chlo- 
roform. It  is  odorless,  but  has  a  disagreeable,  persistent,  bitter 
taste.  It  is  distinctly  alkaline,  and  neutralizes  acids  with  formation 
of  salts.  One  of  these,  the  sulfate,  is  a  white,  crystalline  powder, 
readily  soluble  in  water,  which  is  the  form  in  which  atropin  is  usually 
administered. 

If  atropin  be  acted  upon  by  baryta  at  60°  (140°  F.),  or  by  caustic 
soda,  or  hydrochloric  acid  at  120°-130°  (248°-266°  F.)  it  is  saponi- 
fied, after  the  manner  of  an  ester,  into  tropic,  or  a-phenyl-hydra- 

crylic  acid  (p.  408),  Cells. CH<^CH2OH>  an^  a  basic  substance,  tropin, 
CgHisNO.  But  if  the  action  be  prolonged  the  tropic  acid  is  further 
decomposed  into  a-phenyl-acrylic,  or  atropic,  and  isatropic  acids 
(p.  402).  And  if,  during  the  action  of  HC1,  the  temperature  rises 
to  180°  (356°  F.),  the  tropin  loses  water  and  is  converted  into 
tropidin,  CgHisN. 

As  the  total  syntheses  of  atropin  and  of  tropin  have  not  been 
accomplished,  their  structural  formulae  are  not  definitely  established; 
but,  according  to  the  most  recent  investigations,  it  is  probable  that 
tropidin  consists  of  a  pyrrolidin  ring  condensed  with  a  tetrahydro-n- 
methyl- pyridin  ring,  having  the  group  C-N-C  in  common;  and  that 
tropin  is  derived  from  tropidin  by  rupture  of  the  double  bond  in  the 
pyridin  ring  and  hydration.  It  is  established  that  atropin  is  tropin 
tropate.  The  relations  of  these  bodies,  according  to  these  views,  is 
shown  by  the  following  formulae  : 


476 


MANUAL    OF    CHEMISTRY 


H 

C 

HC        CH 

in 


H2C-CH2 

>NH 
HoC— CH2 


C 
H 

Pyridin. 


H2C 


Pyrrolidin. 

H 
C 

-HC        CHOH 

I          I 

H3C.N       CH2 
\/ 


Tropin. 


H2C        CH 

H3C.N        CH2 
\/ 
C 
H2 

Tetrahydro-n-methyl 
pyridin. 


H2C- 


H2C 


H 
C 

HC        CH 

I          I 

H3C.N       CH2 
\/ 

C 

H 

Tropidin. 


H2 

C 

H2C HC        CH.OOC.CH.CoHs 


I  I 


CH2OH 


H3C.N        CH2 

v 

H2C C 

H 

Tropin-a-phenyl-hydracrylate,  or  Atropin. 


ANALYTICAL  CHARACTERS. — (1)  If  a  fragment  of  potassium  di- 
chromate  be  dissolved  in  a  few  drops  of  H2S04,  the  mixture  warmed, 
a  fragment  of  atropin  and  a  drop  or  two  of  H20  added,  and  the 
mixture  stirred,  an  odor  of  orange-blossoms  is  developed.  (2)  A 
solution  of  atropin  dropped  upon  the  eye  of  a  cat  produces  dilatation 
of  the  pupil.  (3)  The  dry  alkaloid  (or  salt)  is  moistened  with  fuming 
HNOa  and  the  mixture  dried  on  the  water -bath.  When  cold,  it  is 
moistened  with  an  alcoholic  solution  of  KHO :  a  violet  color,  which 
changes  to  red  (Vitali).  (4)  If  a  saturated  solution  of  Br  in  HBr 
be  added  to  a  solution  of  atropin,  a  yellow  precipitate  is  formed, 
which  rapidly  becomes  crystalline,  and  which  is  insoluble  in  acetic 
acid,  sparingly  soluble  in  EbSCX  and  HC1. 

TOXICOLOGY. — The  clinical  history  of  atropic  poisoning  is  divisible 
into  two  stages,  the  first  one  of  delirium,  in  which  the  prominent 
symptoms  are  dryness  of  the  throat,  thirst,  difficulty  of  deglutition 
and  spasms  upon  swallowing  liquids,  face  at  first  pale,  afterwards 
highly  reddened,  pulse  extremely  rapid,  eyes  prominent,  brilliant, 
with  widely -dilated  pupils,  complete  paralysis  of  accommodation, 
disturbances  of  vision,  attacks  of  giddiness  and  vertigo,  with  severe 
headache,  followed  by  delirium,  occasionally  silent  or  muttering,  but 
usually  violent,  noisy  and  destructive,  accompanied  by  the  most  fan- 
tastic delusions  and  hallucinations.  Usually  the  urine  is  retained, 
and  the  body  temperature  is  above  the  normal.  The  delirium  grad- 
ually subsides,  and  the  second  stage,  that  of  coma,  is  established,  with 
slow,  stertorous  respiration,  and  gradually  failing  pulse,  until  death 
occurs  from  respiratory  or  cardiac  paralysis,  or  sometimes  in  an 
attack  of  syncope  during  apparent  amelioration.  In  some  cases,  the 
patient  rapidly  becomes  comatose  at  the  outset,  and  the  symptoms  of 


PYEIDIN    ALKALOIDS  477 

the  first  stage  are  manifested  as  the  coma  diminishes.  The  treatment 
should  consist  of  lavage  of  the  stomach,  and  morphin  may  be  given 
cautiously  during  the  period  of  violent  excitement.  In  the  second 
stage,  the  treatment  is  the  same  as  in  morphin  poisoning.  Pilocarpin 
may  be  given,  in  not  too  large  doses,  to  stimulate  the  secretion  of 
saliva.  Atropic  poisoning  leaves  no  characteristic  post-mortem 
lesions. 

Tropeins  —  are  ester-like  derivatives  of  tropin  with  acids,  similar 
to  atropin.  Many  such  have  been  formed  with  organic  acids,  benzoic, 
salicylic,  etc.  That  formed  with  mandelic  acid  (p.  408)  is  known  as 
homatropin,  C8Hi4N.OOC.CH(OH).C6H5,  and  is  used  as  a  mydriatic 
having  a  less  prolonged  action  than  atropiu.  Only  those  trope'ins 
whose  acid  radicals  contain  an  alcoholic  hydroxyl  have  a  mydriatic 
action. 

Cocain  —  Ci7H2iNO4 — the  most  important  of  the  alkaloids  of 
Erythroxylon  coca,  is  closely  related,  chemically,  to  atropin.  It 
crystallizes  in  large  four-  or  six-sided  prisms;  f .  p.  98°;  sparingly 
soluble  in  water,  readily  soluble  in  alcohol,  ether  or  chloroform, 
somewhat  bitter  at  first,  but  causing  paralysis  of  the  sense  of  taste 
afterwards;  strongly  alkaline.  Its  hydrochlorid,  used  as  a  local 
anaesthetic,  crystallizes  in  prismatic  needles,  readily  soluble  in  water. 
When  boiled  with  water,  cocain  is  hydrolised  into  benzoyl-ecgonin, 
Ci6HigNO4,  and  methylic  alcohol.  If  the  saponification  be  effected 
by  baryta,  or  by  concentrated  mineral  acids,  it  is  more  complete,  and 
ecgonin,  CgHisNOs,  and  benzoic  acid  and  methylic  alcohol  are  formed. 
Cocain  may  also  be  regenerated  by  acting  upon  ecgonin  with  a 
mixture  of  methyl  iodid  and  benzoic  anhydrid.  Or,  by  substitu- 
ting other  alkyl  iodids  for  that  of  methyl,  other  alkaloids,  homol- 
ogous with  cocain,  may  be  obtained.  Ecgonin  combines  with  bases 
to  form  salts,  and  also  with  anhydrids  to  form  esters.  It  is,  there- 
fore, both  acid  and  basic  in  character,  and  yields  numerous  products 
of  derivation  besides  cocain.  Cocain  is  the  methyl  ester  of  benzoyl- 
ecgonin,  and  ecgonin  is  tropin -/2-carboxylic  acid.  Compare  the 
formula?  of  ecgonin  and  cocain  below  with  those  of  tropin  and  atropin 
(p.  476): 


H2( 
T=r~r 


H     COOH  H     COO.CHs 

\/  \/ 

G  G 

/\  /\ 

H2C HC        CHOH  H2C HC        CHO.CO.C6H5 


I 

H3C.N       CH2 

\x 


H3C.N        CH5 
\/ 


\j 


H  H 

Tropin-/3-carboxylic  acid.  Methyl-benzoyl  ecgonate 

Ecgonin.  Cocain. 


478  MANUAL    OF    CHEMISTRY 

ANALYTICAL  CHARACTERS. —  The  reactions  of  cocain  are  not  very 
marked.  (1)  Picric  acid  forms  a  yellow  ppt.  in  concentrated  solu- 
tions. (2)  A  solution  of  iodin  in  KI  solution  gives  a  fine  red 
precipitate  in  a  solution  containing  1  to  10,000  of  cocain.  (3)  When 
cocain  or  one  of  its  salts,  dried  at  100°  (212°  F.),  is  moistened  with 
fuming  HNOs,  evaporated  to  dryness,  and  the  residue  taken  up 
with  alcoholic  solution  of  KHO,  a  strong  odor  resembling  that  of 
peppermint  is  developed,  due  to  the  formation  of  ethyl  benzoate. 

Pilocarpin  —  CiiHi6N2O2  —  occurs  in  jaborandi,  along  with  two 
other  alkaloids,  jaborin,  C22H32N4O4 ( ? ) ,  and  pilocarpidin,  CioHi4N2O2, 
and  an  essential  oil,  consisting  principally  of  pilocarpene,  Ci0Hi6.  It 
is  colorless,  crystalline,  readily  soluble  in  water,  alcohol,  ether  and 
chloroform.  It  is  converted  by  heat  into  jaborin;  and  by  HNOs  or 
HC1  into  a  mixture  of  jaborin  and  jaborandin,  CioHi2N203.  Like 
piperin,  atropin,  cocain,  etc.,  it  is  ethereal  in  character  and  is  decom- 
posed into  CO2,  methylamin,  butyric  acid,  and  pyridin  bases  by  KHO 
or  NaHO.  When  oxidized  by  potassium  permanganate  it  yields 
pyridin-tartronic  acid,  C5H4N.C  \  (OH)  (COOH)2,  and  this,  on  further 
oxidation,  nicotinic  acid,  CsHtN.COOH.  When  its  hydrochlorid  is 
heated  to  200°,  in  presence  of  H2O,  it  takes  up  water  and  is  decom- 
posed into  pilocarpidin  and  methylic  alcohol.  Conversely,  pilocarpin 
is  produced  by  the  action  of  methyl  iodid  upon  pilocarpidin. 
Although  the  constitution  of  pilocarpin  is  not  established,  the  above 
and  other  reactions  indicate  that  it  contains  the  pyridin  ring,  to 
which  the  cyclic  group,  CeHi2NO2,  is  attached  in  the  ft  position;  and 
that  it  is  methyl -pilocarpidin. 

Other  alkaloids  belonging  to  this  group  are:  trigonellin, 
C7H?NO2,  from  fenugreek;  arecolin,  CsHisNO^  arecaidin,  C7HnNO2, 
arecain.  C7HnNO2,  and  guvacin,  C6HgNO2,  from  the  betel -nut; 
chrysanthemin,  Ci4H2sN2O3,  from  chrysanthemum;  hyoscyamin,  and 
pseudohyoscyamin,  isomeric  with  atropin,  and  hyoscin,  Ci7H23NO4, 
from  various  species  of  Solanacece ;  pelletierin,  CgHisNO,  and  its  de- 
rivatives, from  pomegranate -seeds;  spartein,  Ci5H26N2,  from  broom; 
and  cytisin,  CnHi4N2O,  from  laburnum -seeds. 

QUINOLIN  ALKALOIDS. 

Cinchona  Alkaloids — Although  by  no  means  so  complex  a  sub- 
stance as  opium,  cinchona  bark  contains  a  great  number  of 
substances:  quinin,  cinchonin,  quinidin,  cinchonidin,  aricin;  quinic, 
quinotannic  and  quinovic  acids;  cinchona -red,  etc.  Of  these  the  most 
important  are  quinin  and  cinchonin. 

Quinin  — Quinina  (U.  S.)  —  C2oH24N2O2 -fn  Aq— 324+nl8— exists 
in  the  bark  of  a  variety  of  trees  of  the  genera  Cinchona  and  China, 


QUINOLIN    ALKALOIDS  479 

which  vary  considerably  in  their  richness  in  this  alkaloid.  The 
best  samples  of  calisaya  bark  contain  from  30  to  32  parts  per  1,000 
of  the  sulfate;  the  intermediate  grades  4  to  20  parts  per  1,000; 
inferior  grades  of  bark  contain  from  mere  traces  to  6  parts  per 
1,000. 

It  is  known  in  three  different  states  of  hydration,  with  1,  2,  and  3 
Aq,  and  anhydrous.  The  anhydrous  form  is  an  amorphous,  resinous 
substance,  obtained  by  evaporation  of  solutions  in  anhydrous  alcohol 
or  ether.  The  first  hydrate  is  obtained  in  crystals  by  exposing  to 
air  recently  precipitated  and  well-washed  quinin.  The  second  by 
precipitating  by  ammonia  a  solution  of  quinin  sulfate,  in  which  H 
has  been  previously  liberated  by  the  action  of  Zn  upon  H2SO4;  it  is 
a  greenish,  resinous  body,  which  loses  B^O  at  150°  (302°  F.).  The 
third,  that  to  which  the  following  remarks  apply,  is  formed  by  pre- 
cipitating solutions  of  quinin  salts  with  ammonia. 

It  crystallizes  in  hexagonal  prisms;  very  bitter;  fuses  at  57° 
(134.6°  F.) ;  loses  1  Aq  at  100°  (212°  F.),  and  the  remainder  at  125° 
(257°  F.);  becomes  colored,  swells  up,  and,  finally,  burns  with  a 
smoky  flame.  It  does  not  sublime.  It  dissolves  in  2,200  pts.  of  cold 
water,  in  763  of  hot  water,  very  soluble  in  alcohol  and  chloroform ; 
soluble  in  arnyl  alcohol,  benzene,  fatty  and  essential  oils,  and  ether. 
Its  alcoholic  solution  is  powerfully  lasvogyrous,  [a]D= — 270.7°  at  18° 
(64.4°  F.),  which  is  diminished  by  increase  of  temperature,  but  in- 
creased by  the  presence  of  acids. 

ANALYTICAL  CHARACTERS.— (1)  Dilute  H2S04  dissolves  quinin 
in  colorless  but  fluorescent  solution  (see  below).  (2)  Solutions  of 
quinin  salts  turn  green  when  treated  with  chlorin- water  and  then 
with  ammonium  hydroxid.  (3)  Chlorin  passed  through  water  hold- 
ing quinin  in  suspension  forms  a  red  solution.  (4)  Solution  of 
quinin  treated  with  chlorin -water  and  then  with  fragments  of  po- 
tassium ferrocyanid  becomes  pink,  passing  to  red. 

SULFATE — Disulfate  —  Quininse  sulfas  (U.  S.)  —  Quiniae  sulfas 
(Br.)— SO4(C2oH25N2O2)2-|-7Aq— 746+126— crystallizes  in  prismatic 
needles;  very  light;  intensely  bitter;  phosphorescent  at  100°  (212° 
F.);  fuses  readily;  loses  its  Aq  at  120°  (248°  F.),  turns  red,  and 
finally  carbonizes;  effloresces  in  air,  losing  6  Aq;  soluble  in  740  pts. 
of  water  at  13°  (55.4°  F),  in  30  pts.  of  boiling  water,  and  60  pts.  of 
alcohol.  Its  solution  with  alcoholic  solution  of  iodin  deposits  bril- 
liant green  crystals  of  iodoquinin  sulfate. 

HYDROSULFATE— Quininae  bisulfas  (U.  S.)—  SO4H(C2oH25N2O2)4- 
7  Aq  — 422+126 — is  formed  when  the  sulfate  is  dissolved  in  excess 
of  dilute  H2SO4.  It  crystallizes  in  long,  silky  needles,  or  in  short, 
rectangular  prisms;  soluble  in  10  pts.  of  water  at  15°  (59°  F.).  Its 
solutions  exhibit  a  marked  fluorescence,  being  colorless,  but  showing  a 


480  MANUAL    OF    CHEMISTRY 

fine  pale -blue  color  when  illuminated  by  a  bright  light  against  a 
dark  background. 

By  the  action  of  alkaline  hydroxids  upon  quinin,  formic  acid, 
quinolin  (p.  468),  and  pyridin  bases  (p.  459)  are  produced. 

Concentrated  HC1  at  140°-150°  (284°-302°  F.)  decomposes  quinin 
with  separation  of  methyl  chlorid  and  formation  of  apoquinin,  Cig- 
H22N2O2,  an  amorphous  base. 

Oxidizing  agents  produce  from  quinin  oxalic  acid  and  pyridin  car- 
boxylic  acids,  notably  pyridin-2,  3-dicarboxylic,  or  cinchomeronic, 
acid,  CsHaNCCOOHh,  which  are  also  formed  by  oxidation  of  cin- 
chonin. 

Although  cinchonin  differs  from  quinin  in  composition  by  CH^O, 
and  although  the  decompositions  of  the  two  bases  show  them  both  to 
be  related  to  the  quinolin  and  pyridin  bases,  attempts  to  convert  cin- 
chonin into  quinin  have  resulted  only  in  the  formation  of  other 
products,  among  which  is  an  isomere  of  quinin,  oxycinchonin. 

Methylquinin,  C2oH24N202CH3,  is  a  base  which  has  a  curare-like 
action . 

Cinchonin — Cinchonina  (U.  S.) — CioEta^O — 294 — occurs  in  Pe- 
ruvian bark  to  the  amount  of  from  2  to  30  pts.  per  1,000.  It  crys- 
tallizes without  Aq  in  colorless  prisms;  fuses  at  150°(302°F.) ;  soluble 
in  3,810  pts.  of  water  at  10°  (50°  F.),  in  2,500  pts.  of  boiling  water; 
in  140  parts  of  alcohol,  and  in  40  pts.  of  chloroform.  The  salts  of 
cinchonin  resemble  those  of  quinin  in  composition;  are  quite  soluble 
in  water  and  in  alcohol;  are  not  fluorescent;  are  permanent  in  air; 
and  are  phosphorescent  at  100°  (212°  F.). 

Quinidin  and  Quinicin — are  bases  isomeric  with  quinin  ;  the 
former  occurring  in  cinchona  bark,  and  distinguishable  from  quinin 
by  its  strong  dextrorotary  power;  the  second  a  product  of  the  action 
of  heat  on  quinin,  not  existing  in  cinchona. 

Cinchonidin — a  base,  isomeric  with  cinchonin,  occurring  in  cer- 
tain varieties  of  bark;  laevogyrous.  At  130°  (266°  F.),  H2S04  con- 
verts it  into  another  isomere,  cinchonicin. 

Constitution  of  Cinchona  Alkaloids — The  constitution  of  no 
cinchona  alkaloid  has  yet  been  completely  determined.  Enough  has, 
however,  been  ascertained  to  show  that  cinchonin  and  quinin  con- 
tain a  quinolin  nucleus,  united  to  another  cyclic  nucleus,  containing 
the  second  N  atom,  and  which  is  probably  a  modified  piperidin.  The 
difference  between  the  empirical  formulae  of  cinchonin,  CigH^^O, 
and  of  quinin,  C2oH24N2O2,  is  CH.2O  in  favor  of  the  latter,  which 
would  represent  the  substitution  of  methoxyl,  CHsO,  for  H.  When 
cinchonin  and  quinin  are  oxidized  by  chromic  acid  they  yield  two 
quinolin  -carboxylic  acids  also  differing  from  each  other  by  ClbO. 
Cinchonin  yields  cinchoninic  acid,  which  is  known  to  be  y- quinolin 


QUINOLIN    ALKALOIDS 


481 


carboxylic  acid;  while  quinin  yields  quinic  acid,  which  has  been 
shown  to  be  the  methyl  -  phenol  ether  of  p-oxyquinolin -7 -carboxylic 
acid  (see  formulas  below).  Therefore  the  group  CH2O,  by  which 
cinchonin  and  quinolin  differ,  exists  in  the  quinolin  ring,  and  the 
"second  half,"  or  the  portion  of  the  molecule  other  than  the  quinolin 
ring,  is  the  same  in  the  two  alkaloids.  This  is  further  proven  by  the 
fact  that 'on  decomposition  by  PCls  and  subsequent  treatment  with 
alcoholic  KHO,  cinchonin  yields  lepidin,  CioHgN,  the  next  superior 
homologue  of  quinolin.  CgHyN,  while  quinin  yields  p-methoxy- lepidin, 
CioHslOCHsJN,  and  the  other  product  of  the  decomposition  is  one 
and  the  same  substance  from  either  alkaloid,  a  substance  which  has 
been  called  meroquinene,  CgHisNC^,  which  on  treatment  with  HgC^ 
and  HC1  is  converted  into  ft- ethyl -7- methyl -pyridin,  and  whose  prob- 
able constitution  is  expressed  by  the  formula  given  below.  So  far  as 
determined,  therefore,  the  formulaB  of  cinchonin  and  of  quinin  are 
those  here  given,  the  arrangement  of  the  group  CioHi5(OH)N 
remaining  to  be  determined  : 


H      COOH 


HC        C        CH 

I          II          I 
HC        C        CH 

V  \S 

C       N 

H 

Cinchoninic  acid, 
(7-Quinolin  car- 
boxylic acid). 

CH3 
C 


H 

COOH 

1 

1 

C 

C 

/-N. 

CH3O.C 

/     N 

c 

CH 

1 

II 

1 

HC 

c 

CH 

v/ 

\^ 

'/ 

c 

N 

H    CH2.COOH 


H2C 
H2C 


C 
/\ 


\ 


CH:CH2 


Quinic  acid,  (3-Meth- 

oxyquinolin'7-car- 

boxylic  acid). 

H       Ci0H15(OH)N 
C        C 


CH2 
\/ 

N 

H 

Meroquinene  (?) 


H 

I 
c 


HC        C—  CH2.CH3 

I          II 
HC        CH 

V 

N 


/3  -  Ethyl  -  7-  methyl-pyridin. 


HC        C        CH 

I          II         I 
HC        C        CH 

V  \S 

C        H 

H 

Cinchonin. 


CH3O— C 


HC        C 

V  \S 

C       H 

H 

Quinin. 


Ci0HI5(OH)N 

i 
c 


CH 

I 
CH 


Alkaloids  of  the  Loganiacese — Strychnos  Alkaloids. — This  group 
includes  strychnin  and  brucin  and  their  alkyl  derivatives,  and  the 
curare  alkaloids. 

Strychnin  —  C2iH22N2O2 — exists  in  the  seeds  and  bark  of  different 
varieties  of  Strychnos,  notably  Strychnos  nux-vomica. 

It  crystallizes  on  slow  evaporation  of  its  solutions  in  orthorhombic 
31 


482  MANUAL    OP    CHEMISTRY 

prisms;  very  sparingly  soluble  in  water  and  in  strong  alcohol;  soluble 
in  5  parts  of  chloroform.  Its  aqueous  solution  is  intensely  bitter,  the 
taste  being  perceptible  in  a  solution  containing  1  part  in  200,000, 

It  is  a  powerful  base;  neutralizes  and  dissolves  in  concentrated 
H2SO4  without  coloration,  and  precipitates  many  metallic  oxids  from 
solutions  of  their  salts.  Its  salts  are  mostly  crystallizable,  soluble  in 
water  and  in  alcohol,  and  intensely  bitter.  The  acetate  is  the  most 
soluble.  The  neutral  sulfate  crystallizes,  with  7  Aq,  in  rectangular 
prisms.  Methyl  and  ethyl  iodids  react  with  strychnin  to  produce 
methyl  or  ethyl strychnium  iodids,  white,  crystalline  substances, 
producing  an  action  on  the  economy  similar  to  that  of  curare.  Heated 
with  fuming  HNOs,  strychnin  yields  picric  acid.  Heated  with  baryta 
water  to  130°,  it  yields  isostrychnic  acid,  C2oH23N2O.COOH;  and 
when  treated  with  sodium  alcoholate,  strychnia  acid,  by  addition  of 
H2O.  By  boiling  with  concentrated  hydriodic  acid  and  red  phos- 
phorus it  is  converted  into  desoxy strychnin,  C2iH2eN2O,  which  is 
further  reduced  by  electrolysis  to  dihydrostrychnolin,  C2iH2sN2. 
Strychnin  itself,  by  electrolysis,  forms  two  bases,  tetrahydro- strych- 
nin, C2iH2eN2O2,  and  strychnidin,  C2iH24N2O.  But  little  is  known 
of  the  constitution  of  strychnin,  which  is,  however,  probably  a  de- 
rivative of  tetrahydroquinolin. 

ANALYTICAL  CHARACTERS. — (1)  Dissolves  in  concentrated  H2SO4, 
without  color.  The  solution  deposits  strychnin  when  diluted  with 
water,  or  when  neutralized  with  magnesia  or  an  alkali.  (2)  If  a 
fragment  of  potassium  dichromate  (or  other  substance  capable  of 
yielding  nascent  oxygen)  be  drawn  through  a  solution  of  strychnin  in 
H2SO4,  it  is  followed  by  a  streak  of  color;  at  first  blue  (very  transi- 
tory and  frequently  not  observed),  then  a  brilliant  violet,  which 
slowly  passes  to  rose -pink,  and  finally  to  yellow.  Reacts  with  50000 
grain  of  strychnin.  (3)  A  dilute  solution  of  potassium  dichromate 
forms  a  yellow,  crystalline  ppt.  in  strychnin  solutions,  which,  when 
washed  and  treated  with  concentrated  H2SO4,  gives  the  play  of  colors 
indicated  in  2.  (4)  If  a  solution  of  strychnin  be  evaporated  on  a  bit 
of  platinum  foil,  the  residue  moistened  with  concentrated  H2SO4,  the 
foil  connected  with  the  +  pole  of  a  single  Grove  cell,  and  a  platinum 
wire  from  the  —  pole  brought  in  contact  with  the  surface  of  the  acid, 
a  violet  color  appears  upon  the  surface  of  the  foil.  (5)  Strychnin 
and  its  salts  are  intensely  bitter.  (6)  A  solution  of  strychnin  intro- 
duced under  the  skin  of  the  back  of  a  frog  causes  difficulty  of 
respiration  and  tetanic  spasms,  which  are  aggravated  by  the  slightest 
irritation,  and  twitching  of  the  muscles  during  the  intervals  between 
the  convulsions.  With  a  small  frog,  leooo  grain  of  strychnium  acetate 
will  produce  tetanic  spasms  in  ten  minutes.  White  mice,  14  to  16 
days  old,  are  even  more  susceptible  to  the  action  of  strychnin  than 


ISOQUINOLIN    ALKALOIDS  483 

frogs.  (7)  Solid  strychnin,  moistened  with  a  solution  of  iodic  acid  in 
H2SO4,  produces  a  yellow  color,  changing  to  brick-red,  and  then  to 
violet-red.  (8)  Moderately  concentrated  HNOa  colors  strychnin  yellow 
in  the  cold.  (9)  A  warm  solution  of  strychnin  in  dilute  HNOa  pro- 
duces a  scarlet-red  color  on  addition  of  a  little  KClOs.  A  drop  or  two 
of  ammonia  changes  this  to  brown.  On  evaporation  to  dryness,  a 
green  residue  remains,  which  forms  a  green  solution  in  water,  changes 
to  orange -brown  with  KHO,  and  returns  to  green  with  HNOa. 

TOXICOLOGY. —  Strychnin  produces  a  sense  of  suffocation,  thirst, 
tetanic  spasms,  usually  opisthotonos,  sometimes  emprosthotonos,  oc- 
casionally vomiting,  contraction  of  the  pupils  during  the  spasms, 
and  death,  either  by  asphyxia  during  a  paroxysm,  or  by  exhaustion 
during  a  remission.  The  symptoms  appear  in  from  a  few  minutes  to 
an  hour  after  taking  the  poison,  usually  in  less  than  twenty  minutes; 
and  death  in  from  five  minutes  to  six  hours,  usually  within  two  hours. 
Death  has  been  caused  by  /£  grain,  and  recovery  has  followed  the 
taking  of  20  grains. 

The  treatment  should  consist  in  bringing  the  patient  under  the 
influence  of  chloral  hydrate  or  of  chloroform,  and  then  washing  out 
the  stomach.  The  patient  should  be  kept  as  quiet  as  possible,  as 
the  slightest  unexpected  irritation  will  produce  a  spasm. 

Strychnin  is  one  of  the  most  stable  of  the  alkaloids,  and  may 
remain  for  a  long  time  in  contact  with  putrefying  organic  matter 
without  suffering  decomposition. 

Brucin  —  C23H26N2O4-f  4Aq—  394  +72  —  accompanies  strychnin . 
It  forms  oblique  rhomboidal  prisms,  which  lose  their  Aq  in  dry  air. 
Sparingly  soluble  in  E^O,  readily  soluble  in  alcohol,  chloroform,  and 
amyl  alcohol;  intensely  bitter.  It  is  a  powerful  base  and  most  of 
its  salts  are  soluble  and  crystalline.  Its  action  on  the  economy  is 
similar  to  that  of  strychnin,  but  much  less  energetic. 

ANALYTICAL  CHARACTERS.  —  ( 1 )  Concentrated  HNOs  colors  it 
bright  red,  soon  passing  to  yellow ;  stannous  chlorid,  or  colorless 
NH4HS,  changes  the  red  color  to  violet.  (2)  Chlorin- water,  or  Cl, 
colors  brucin  bright  red,  changed  to  yellowish -brown  by  NEUHO. 

Curarin  —  CaeHssNC?) — is  an  alkaloid  obtainable  from  the  South 
American  arrow -poison,  curare,  or  woorara.  It  crystallizes  in  four- 
sided,  colorless  prisms,  which  are  hygroscopic,  faintly  alkaline,  and 
intensely  bitter. 

Curarin  dissolves  in  H2SO4,  forming  a  pale- violet  solution,  which 
slowly  changes  to  red.  If  a  crystal  of  potassium  dichromate  be 
drawn  through  the  EbSC^  solution,  it  is  followed  by  a  violet  colora- 
tion, which  differs  from  the  similar  color  obtained  with  strychnin 
under  similar  circumstances,  in  being  more  permanent,  and  in  the 
absence  of  the  following  pink  and  yellow  tints. 


484  MANUAL    OF    CHEMISTRY 

ISOQUINOLIN    ALKALOIDS. 

The  opium,  hydrastis,  berberis  and  corydalis  alkaloids  are  in- 
cluded in  this  group.  Of  the  opium  alkaloids,  papaverin,  narcotin 
and  narce'in  are  certainly  derivatives  of  isoquinolin.  Morphin  and 
codem,  on  the  other  hand,  do  not  contain  the  isoquinolin  nucleus, 
but  a  phenanthrene  nucleus  having  a  nitrogen -containing  ring  con- 
densed upon  it.  But  until  the  constitution  of  these  two  alkaloids  is 
established  with  more  completeness  it  is  not  desirable  to  separate 
them  from  their  congeners  (see  p.  488). 

Opium  Alkaloids. —  Opium  is  the  dried  juice  obtained  by  making 
incisions  in  the  unripe  capsules  of  the  poppy,  Papaver  somniferum. 
It  is  of  exceeding  complex  composition,  and  contains  meconic  (p.  459) , 
lactic  and  sulfuric  acids,  with  which  the  alkaloids  are  in  combination, 
meconin  (p.  407),  gum,  caoutchouc,  wax,  sugar,  resins,  etc.,  and  a 
number  of  alkaloids.  Some  twenty  alkaloids  have  been  obtained 
from  opium,  but  of  these  several  are  probably  produced  by  the  pro- 
cesses of  extraction.  The  most  important  of  the  natural  alkaloids 
and  the  average  percentage  in  which  they  exist  in  opium  of  good 
quality  are:  morphin,  10%;  narcotin,  6%;  papaverin,  1%;  codem, 
0.3%;  narcem,  0.2%;  and  theba'in,  0.15%. 

Morphin  —  Morphina  (U.  S.)— Ci7Hi9N03+Aq— 285+18  —  crys- 
tallizes in  colorless  prisms;  odorless,  but  very  bitter;  it  fuses  at  120° 
(248°  F.),  losing  its  Aq.  More  strongly  heated,  it  swells  up,  be- 
comes carbonized,  and  finally  burns.  It  is  soluble  in  1,000  pts.  of 
cold  water,  in  400  pts.  of  boiling  water;  in  265  pts.  of  alcohol  of  90  per 
cent,  at  10°,  and  in  33  pts.  of  boiling  alcohol  of  the  same  strength; 
in  373  pts.  of  cold  amyl  alcohol,  much  more  soluble  in  the  same 
liquid  warm;  almost  insoluble  in  aqueous  ether;  rather  more  soluble 
in  alcoholic  ether;  almost  insoluble  in  benzene;  soluble  in  2,500  pts. 
of  chloroform  at  9°,  and  in  45  pts.  at  56°.  All  the  solvents  dissolve 
morphin  more  readily  and  more  copiously  when  it  is  freshly  pre- 
cipitated from  solutions  of  its  salts  than  when  it  has  assumed  the 
crystalline  form. 

Morphin  combines  with  acids  to  form  crystallizable  salts,  of  which 
the  hydrochlorid,  sulfate  and  acetate  are  used  in  medicine.  If  mor- 
phin be  heated  for  some  hours  with  excess  of  HC1,  under  pressure, 
to  150°  (302°  F.),  it  loses  water,  and  is  converted  into  a  new  base — 
apomorphin,  Ci7HnNO2. 

By  heating  together  acetic  anhydrid  and  morphin,  three  modi- 
fications, «,  /?,  7,  of  acetyl-morphin,  CnHis^HsOWOs,  are  formed. 
Similarly  substituted  butyryl-,  benzoyl-,  succinyl-,  camphoryl-, 
methyl-,  and  ethyl-morphin  are  also  known. 

Morphin  is  readily  oxidized  and  is  a  strong  reducing  agent.     It 


ISOQUINOLIN    ALKALOIDS  485 

reduces  the  salts  of  gold  and  silver  in  the  cold.  It  is  oxidized  by  at- 
mospheric oxygen  when  it  is  in  alkaline  solution,  as  well  as  by  nitrous 
acid,  potassium  permanganate,  potassium  ferricyanid,  or  ammoniacal 
cupric  sulfate,  with  the  formation  of  a  non- toxic  compound  which  has 
received  the  names  oxymorphin,  oxydimorphin,  dehydromorphin, 
and  pseudomorphin  (CnHigNOsh,  whose  molecule  consists  of  two 
morphin  molecules,  united  with  loss  of  H2,  and  which  is  an  inferior 
degree  of  condensation  to  trimorphin  and  tetramorphin,  two  amor- 
phous, basic  products  of  the  action  of  H2SO4  on  morphin  at  100° 
(212°  F.).  When  morphin  is  distilled  with  powdered  zinc,  the  prin- 
cipal product  of  the  reaction  is  phenanthrene,  accompanied  by  am- 
monia, trimethylamin,  pyrrole,  pyridin,  and  a  product  having  the 
formula  CnHnN,  probably  phenanthreue-quinolin. 

The  salts  of  morphium  are  crystalline.  The  acetate  is  a  white 
crystalline  powder,  soluble  in  12  parts  of  water,  which  decomposes 
on  exposure  to  air,  with  loss  of  acetic  acid.  The  chlorid  is  less  sol- 
uble, but  more  permanent  than  the  acetate.  The  sulfate  is  the  form 
in  which  morphin  is  the  most  frequently  used  in  medicine.  It 
is  a  very  light,  crystalline,  feathery  powder ;  odorless,  bitter,  and 
neutral  in  reaction.  It  dissolves  in  24  parts  of  water.  Its  solutions 
deposit  morphin  as  a  white  precipitate  on  addition  of  an  alkali.  The 
crystals  contain  5  Aq,  which  they  lose  at  130°  (266  F.). 

ANALYTICAL  CHARACTERS. — (1)  It  is  colored  orange,  changing 
to  yellow,  by  HNOa.  (2)  A  neutral  solution  of  a  morphium  salt 
gives  a  blue  color  with  neutral  solution  of  ferric  chlorid.  (3)  A 
solution  of  molybdic  acid  in  H^SCU  (Frohde's  reagent)  gives  with 
morphin  a  violet  color,  changing  to  blue,  dirty  green,  and  faint 
pink.  Water  discharges  the  color.  (4)  Take  two  test-tubes.  Into 
one  (a)  put  the  solution  of  morphin,  into  the  other  (b)  an  equal 
bulk  of  EbO.  Add  to  each  a  granule  of  iodic  acid  and  agitate; 
a  becomes  yellow  or  brown,  6  remains  colorless.  To  each  add  a 
small  drop  of  chloroform  and  agitate:  the  CHCla  in  a  is  colored 
violet,  that  in  &  remains  colorless.  Float  some  very  dilute  ammo- 
nium hydroxid  solution  on  the  surface  of  the  liquid  in  a;  a  brown 
band  is  formed  at  the  junction  of  the  layers.  (5)  Moisten  the  solid 
material  with  HC1  to  which  a  small  quantity  of  H2SO4  has  been 
added,  and  heat  in  an  air  oven  at  110°  until  HC1  is  expelled:  a  violet- 
colored  liquid  residue  remains.  Add  to  this  a  drop  or  two  of  water 
containing  a  little  HC1,  and  neutralize  with  powdered  sodium  bicar- 
bonate in  slight  excess:  a  pink  or  rose  color  is  produced,  most  dis- 
tinctly visible  on  the  bubbles.  Add  a  drop  of  water  and  a  drop  or  two 
of  alcoholic  solution  of  iodin:  a  green  color  is  developed.  This  reac- 
tion, known  as  the  Pellagri  test,  is  based  upon  the  conversion  of 
morphin  into  apomorphin,  and  consequently  reacts  with  that  alkaloid. 


486  MANUAL    OF    CHEMISTRY 

(6)  Moisten  the  solid  with  concentrated  H2S04,  and  heat  cautiously 
until  white  fumes  begin  to  be  given  off,  cool  and  touch  the  liquid  with 
a  glass  rod  moistened  with  dilute  HNOs:  a  fine  blue-violet  color,  chang- 
ing to  red  and  then  to  orange.  If  the  H2SO<t  contains  oxids  of  nitro- 
gen, as  it  usually  does,  a  violet  tinge  will  be  produced  before  addition 
of  HNO3,  but  then  becomes  much  more  intense.  This  reaction,  known 
as  the  Husemann,  may  be  applied  by  allowing  the  solid  to  remain  in 
contact  with  H2SO4  for  fifteen  to  eighteen  hours  in  place  of  heating. 

These  are  the  most  important  tests  for  morphin,  and  affirmative 
results  with  all  of  them  prove  the  presence  of  that  alkaloid.  Other 
tests  have  been  suggested,  among  which  are  the  following  :  (7) 
Solution  of  morphium  acetate  produces  a  gray  ppt.  when  warmed 
with  ammoniacal  silver  nitrate  solution ;  and  the  filtrate  turns  red  or 
pink  with  HNOs.  (8)  Auric  chlorid  gives  a  yellow  ppt.,  turning 
violet -blue,  with  solutions  of  morphium  salts.  (9)  Add  solution  of 
Fe2Cle  (2-16)  to  solution  of  potassium  ferricyanid  (the  mixture  must 
not  assume  a  blue  color),  add  morphin:  a  deep-blue  color.  (10) 
Heat  morphin  with  concentrated  H2S04  to  200°  (392°  F.)  until  green- 
black;  add  a  drop  of  the  liquid  cautiously  to  water:  the  solution 
turns  blue.  Shake  a  portion  with  ether:  the  ether  turns  purple. 
Shake  another  portion  with  chloroform:  the  chloroform  turns  blue. 
(11)  Warm  the  solid  alkaloid  with  concentrated  H2S04  ;  add  cau- 
tiously a  few  drops  of  alcoholic  solution  of  KHO  (30%):  a  yellow 
color,  changing  to  dirty-red,  then  steel-blue,  and  sky-blue,  and,  with 
a  further  quantity  of  KHO  solution,  cherry -red.  (12)  A  mixture  of 
morphin  and  cane-sugar  (1  to  4)  added  to  concentrated  H2S04  gives 
a  dark-red  color,  which  is  intensified  by  a  drop  of  bromin- water. 

Codein— Codeina  (U.  S.)—Ci8H2iNO3+Aq— 299+18— crystallizes 
in  large  rhombic  prisms,  or  from  ether,  without  Aq,  in  octahedra; 
bitter;  soluble  in  80  pts.  cold  water;  17  pts.  boiling  water;  very 
soluble  in  alcohol,  ether,  chloroform,  benzene;  almost  insoluble  in 
petroleum -ether. 

Codein  is  the  methyl  ether  of  morphin,  or  its  superior  homologue, 
and  resembles  that  alkaloid  in  some  of  its  reactions;  'thus  under 
similar  circumstances  both  form  apomorphin;  and  morphin  may  be 
converted  into  code'in  by  the  action  of  methyl  iodid  in  the  presence  of 
KHO.  Codein,  however,  only  contains  one  OH  group,  and  forms  a 
monoacetyl  derivative  with  acetyl  chlorid,  while  morphin  produces  a 
diacetyl  compound. 

ANALYTICAL  CHARACTERS. — (1)  Cold  concentrated  H2S04  forms 
with  it  a  colorless  solution,  which  turns  blue  after  some  days,  or 
when  warmed.  (2)  Frohde's  reagent  dissolves  it  with  a  dirty-green 
color,  which  after  a  time  turns  blue.  (3)  Chlorin- water  forms  with 
it  a  colorless  solution,  which  turns  yellowish -red  with  NH4HO. 


ISOQUINOLIN    ALKALOIDS  487 

Narcem  —  C23H27NO8+2Aq— 463+36—  crystallizes  in  bitter,  pris- 
matic needles;  sparingly  soluble  in  water,  alcohol,  and  amyl  alcohol; 
insoluble  in  ether,  benzene,  and  petroleum -ether. 

ANALYTICAL  CHARACTERS. — (1)  Concentrated  H2S04  dissolves  it 
with  a  gray -brown  color,  which  changes  to  red,  slowly  at  ordinary 
temperatures,  rapidly  when  heated.  (2)  Frohde's  reagent  colors  it 
dark  olive -green,  passing  to  red  after  a  time,  or  when  heated.  (3) 
lodin  solution  colors  it  blue -violet,  like  starch. 

Narcotin  —  C22H23NO? — 413  —  crystallizes  in  transparent  prisms, 
almost  insoluble  in  water  and  in  petroleum -ether;  soluble  in  alcohol, 
ether,  benzene,  and  chloroform.  Its  salts  are  mostly  uncrystallizable, 
unstable,  and  readily  soluble  in  water  and  in  alcohol. 

Narcotin  is  decomposed  by  H2O  at  140°  (284°  F.),  by  dilute 
H2S04,  or  by  baryta,  with  formation  of  opianic  acid,  CioHioOs,  and 
hydrocotarnin,  C^HisNOs.  Reducing  agents  decompose  it  into  hy- 
drocotarnin  and  meconin,  CioHioO4.  Oxidizing  agents  convert  it 
into  opianic  acid  and  cotarnin,  C^HisNOa. 

ANALYTICAL  CHARACTERS. —  (1)  Concentrated  EbSC^  forms  with 
it  a  solution,  at  first  colorless,  in  a  few  moments  yellow,  and  after 
a  day  or  two  red.  (2)  Its  solution  in  dilute  H2SO4,  if  gradually 
evaporated  until  the  acid  volatilizes,  turns  orange -red,  bluish -violet 
and  reddish -violet.  (3)  Frohde's  reagent  dissolves  it  with  a  greenish 
color,  passing  to  cherry -red. 

Papaverin  —  C2oH2iN(>4  —  crystallizes  in  prisms;  almost  insoluble 
in  water,  easily  soluble  in  chloroform  and  in  hot  alcohol.  It  is 
optically  inactive.  It  forms  a  colorless  solution  with  concentrated 
H2SO4,  which  turns  dark-violet  when  heated.  Acetic  anhydrid  has 
no  action  upon  it. 

Thebain  —  Paramorphin  —  CioIbiNOa — 311 — crystallizes  in  white 
plates;  tasteless  when  pure;  insoluble  in  water,  soluble  in  alcohol, 
ether  and  benzene. 

ANALYTICAL  CHARACTERS.— (1)  With  concentrated  H2SO4:  an  im- 
mediate bright-red  color,  turning  to  yellowish -red.  (2)  Its  solution  in 
chlorin- water  turns  reddish -brown  with  NEUHO.  (3)  With  Frohde's 
reagent:  same  as  1, 

Apomorphin  —  CnHnNC^ — is  used  hypodermically  as  an  emetic 
in  the  shape  of  the  chlorid.  It  is  obtained  by  sealing  morphin,  with 
an  excess  of  strong  HC1,  in  a  thick  glass  tube,  and  heating  the 
whole  to  140°  (252°  F.)  for  two  to  three  hours.  It  is  obtained 
also  by  the  same  process  from  codei'n.  The  free  alkaloid  is  a  white, 
amorphous  solid,  difficultly  soluble  in  water.  The  chlorid  forms 
colorless,  shining  crystals,  which  have  a  tendency  to  assume  a  green- 
ish tint  on  exposure  to  light  and  air.  It  is  odorless,  bitter  and 
neutral;  soluble  in  6.8  parts  of  cold  water. 


488 


MANUAL    OF    CHEMISTRY 


Relations  and  Constitution  of  the  Opium  Alkaloids.— The  al- 
kaloids of  opium  may  be  arranged  in  two  groups:  (I)  Including 
those  which  are  strong  bases,  are  highly  poisonous,  and  contain  three 
or  four  atoms  of  oxygen;  (II)  those  which  are  weak  bases  and  con- 
tain four  to  nine  oxygen  atoms.  So  far  as  known,  the  alkaloids  of 
the  first  group  contain  the  phenanthrene  -  pyridin  nucleus,  while  those 
of  the  second  group  are  derivatives  of  isoquinolin.  The  six  principal 
alkaloids  above  mentioned  are  equally  divided  between  the  two 

groups : 

I.  II. 

Morphin CnHieNOs  Papaverin C2oH2iNO4 

Code'in CisH2iNO3  Narcotin C22H23NO7 

Thebain Ci9H2iNO3  Narcein C23H27NO8 

Papaverin  was  first  recognized  as  an  isoquinolin  derivative.  On 
oxidation  of  papaverin  by  potassium  permanganate,  papaveraldin, 
C2oHi9NO5,  is  formed.  This,  on  fusion  with  caustic  potash,  yields 
veratric  acid,  which  is  3,  4-dimethoxy-benzoic  acid,  CeHa.COOH  : 
(OOHsJao,^,  and  dimethoxyisoquinolin,  the  constitution  of  the  latter 
being  established  by  its  further  decomposition  into  metahemipinic 
acid  and  a- p-y- pyridin -tricarboxylic  acid.  The  relations  of  papaverin 
and  its  products  of  decomposition  are  shown  by  the  following  formula?: 

COOH 
C 

HC          CH 

II  I 

HC  C— OCH3 

\   # 
C 

I 

OCH3 

Veratric  acid,  Metahemipinic  acid, 

(3,  4-Dimethoxy-benzoic  acid).     (4, 5-Dimethoxy-o-phthalic  acid). 


H 

H 

1 

1 

C 

C 

S  \ 

/   ^ 

H3CO-C          C          CH 

1            II            1 
H3CO-C          C          N 

\   / 

\   / 

C 

C 

Dimethoxyiso- 
Quinolin. 

H 

A 

#  \  / 

H3CO—  C 

C 

H 

1 

C 

/, 

'   \ 

H3CO-C 

C—  COOH 

1 

II 

H3CO—  C 

<v 

C—  COOH 

^C 

1 

H 

HOOC-C 

II 

HOOC-C 


H3CO-C 


\ 


\ 


N     HC 


HC 


\ 


CH 


C—  OCH3 


\ 


CH 
N 

C 

COOH 


^C 

OCH3 
Papaverin,  (Tetramethoxy-benzyl-a-isoquinolin).  a-/3-7-Pyridin-tricarboxylic  acid. 


ISOQUINOLIN   ALKALOIDS  489 

Narcotin,  C22H23NO?,  is  converted  by  oxidation  into  opianic  acid, 
(p.  408),  and  cotarnin,  C^H^NO*.  By  hydrolysis  it  yields 
opianic  acid  and  hydrocotarnin,  Ci2Hi5NO3;  and  by  reduction,  meco- 
nin,  CioHuAt  (p.  407),  and  hydrocotarnin.  Narcotin,  therefore, 
contains  the  nuclei  of  opianic  acid,  or  of  meconin,  and  of  hydro- 
cotarnin. The  constitution  of  opianic  acid  is  known,  as  well  as 
that  of  its  reduction  product,  meconin,  but  that  of  hydrocotarnin 
is  not  completely  established.  It  is,  however,  a  derivative  of  iso- 
quinolin,  containing  one  of  the  three  methoxy  groups  (CH3O)  which 
exist  in  narcotin,  and  a  bivalent  group  —  O.CH2.O  —  attached  to 
the  benzene  ring;  and  a  methyl  group,  united  to  the  N  atom  in 
the  pyridin  ring. 

Narcein,  C23H27NOg,  is  formed  by  the  action  of  caustic  potash  upon 
narcotin  iodmethylate :  C22H23NO7.CH3I+KHO— KI+C23H27NO8. 

Morphin,  CnHigNOs,  and  codein,  CigEbiNOs,  are  closely  related. 
Codein  is  produced  by  the  action  of  methyl  iodid  upon  morphin- 
potassium :  CnHisKNOs+CHal  =  KH-Ci7Hi8(CH3)N03.  It  is,  there- 
fore, methyl-morphin.  By  the  further  action  of  methyl  iodid  upon 
codein  in  alcoholic  solution,  codein  methyl  iodid,  CigH^iNOsrCHsI, 
is  produced,  and  this,  when  warmed  with  KHO,  is  converted  into 
methyl-morphin  methine,  CnHigNOs:  CH.CHs.  The  last-named 
substance  is  decomposed  by  acetic  anhydrid  into  methyldioxyphenan- 

threneand  oxethyl-dimethyl-amin:  CnHigNOsrCH.CHs^CuHs^o^Ha 

/CH3 
4-  N— CH3  •   and  other  morphin  and  codein  derivatives  are  sim- 

\CH2.CH2.OH 

ilarly  decomposed,  with  formation,  on  the  one  hand,  of  a  non-nitro- 
genized  oxy-phenanthrene  compound,  and,  on  the  other,  an  oxyamin 
or  a  trialkyl-amin.  Upon  these  facts,  it  is  concluded,  that  the 
morphin  and  codein  molecules  consist  of  an  oxyphenanthrene  group, 

CH3 

N 
upon   which   is   fused   a   nitrogenized    group,  H2C          .     It   is  also 

H2C 
\  / 
O 

recognized  that  the  two  hydroxyls  are  in  the  same  phenanthrene  ring, 
and  that  one  of  them  is  phenolic,  the  other  alcoholic;  also  that  one 
methyl  group  is  attached  to  the  nitrogen  atom.  The  disposal  of  the 
hydrogen  and  hydroxyls  in  the  phenanthrene  nucleus  and  the  position 
of  attachment  of  the  nitrogenized  group  above  referred  to  remain 
undetermined.  Two  formulae  of  constitution  of  morphin  have  been 
proposed,  either  of  which  is  in  consonance  with  the  facts  at  present 
known : 


490  MANUAL    OF    CHEMISTRY 

OH  H 

A  X 

HOHC       \H  H2C          CH 

II  II 

HoC  C  H3C-N-HC  C 

Y>      °<   Y> 

O  0  CH2  H2C  C  CH 

/   \   /   \   /  \  /   \   / 

H2C  C  C  0-HC 

H2C  C  CH  HOC  CHOH 

\  /  \  "/  ^   / 

?     ?  ? 

CH3      H  H 

(I)  (ID 

The  formula  of  code'in  is  derived  from  either  formula  by  substitu- 
tion of  CH3  for  H  in  the  phenolic  OH;  that  of  apomorphin  by 
removal  of  H20. 

Thebain,Ci9H2iNO3,is  decomposed  by  acetic  anhydrid  in  a  manner 
quite  analogous  to  the  decomposition  of  morphin,  above  referred  to, 
but  yielding  a  dimethoxy- phenolic  derivative  of  phenanthrene,  called 
thebaol,  and  methyl-oxethyl-amin:  Ci9H2lN03-hH20  — (CH30)2Cl4H7.- 
/FT 

OH+N— CH3  Like  morphin  and   code'in,  it   is   therefore  a 

\CH2.CH2.OH 

phenanthrene -pyridin  derivative. 

Toxicology  of  Opium  and  its  Derivatives. —  Opium,  its  prepara- 
tions and  the  alkaloids  obtained  from  it  are  all  active  poisons.  The 
alkaloids  have  not  all  the  same  action.  In  soporific  effects,  beginning 
with  the  most  powerful,  they  rank  thus:  narcotin,  morphin,  code'in; 
in  tetanizing  action:  theba'in,  papaverin,  narcotin,  code'in,  morphin; 
in  toxic  action:  theba'in,  code'in,  papaverin,  narce'in,  morphin,  narcotin. 

The  symptoms  set  in  in  from  ten  minutes  to  three  hours,  excep- 
tionally "immediately,"  or  only  after  eighteen  hours.  They  are 
divisible  into  three  periods:  (1)  a  stage  of  excitement,  marked  by 
great  physical  activity,  loquacity  and  imaginative  power;  is  of  short 
duration;  longest  in  opium  habitues,  absent  with  large  doses;  (2)  a 
period  of  sopor,  in  which  there  are  diminished  sensibility,  weariness, 
contracted  pupils,  pale  face,  livid  lips,  drowsiness,  increasing  to  deep 
sleep,  from  which,  however,  the  patient  may  be  roused,  and  when  so 
roused  is  coherent  in  speech.  This  stage  merges  insensibly  into  the 
third,  that  of  coma.  The  patient  can  no  longer  be  aroused,  even  by 
violent  means.  The  face  is  pale,  the  lips  cyanosed,  the  muscular 
system  completely  relaxed,  the  reflexes  abolished,  the  pupils  con- 
tracted greatly,  and  insensible  to  light,  the  pulse  slow,  irregular, 


/*  f\  w\  -wv  T»  f\ 


ALKALOIDS    OF    UNKNOWN    CONSTITUTION  491 


compressible,  and  finally  imperceptible,  the  respiration  more  and 
more  infrequent,  stertorous,  shallow,  and  accompanied  by  mucous 
rales.  Retention  of  urine  begins  early  in  the  poisoning.  The  usual 
duration  of  a  fatal  poisoning  is  from  six  to  twenty -four  hours. 
Deaths  have  occurred  in  forty -five  minutes  and  in  three  days. 

The  minimum  lethal  dose  for  a  non- habituated  adult  is  probably 
3  to  4  grains.  Young  children  are  very  susceptible.  Tolerance  to  a 
remarkable  degree  is  established  by  habit,  both  in  children  and  in 
adults,  and  instances  are  reported  in  which  50  to  60  grains  have  been 
taken  daily,  without  toxic  effects,  by  morphin- takers. 

The  treatment  should  consist  in  washing  out  the  stomach  with  a 
dilute  solution  of  potassium  permanganate,  leaving  about  500  cc.  in 
the  stomach,  and  in  maintaining  the  respiration.  In  the  first  or  sec- 
ond stage  the  "ambulatory  treatment"  should  be  adopted  to  prevent, 
if  possible,  the  establishment  of  the  third  stage.  If  this  stage  develop, 
the  main  reliance  is  to  be  placed  in  maintaining  the  respiration  by 
artificial  methods,  until  the  poison  has  been  eliminated.  Strong  coffee, 
or  caff  em,  by  the  mouth  or  rectum  are  of  benefit.  The  same  cannot 
be  said  of  the  atropin.  The  urine  should  be  drawn  by  the  catheter. 

The  opiates  leave  no  post-mortem  lesions,  except  such  as  are 
usually  observed  after  death  from  asphyxia,  i.  e.,  congestion  of  the 
vessels  of  the  brain  and  meninges,  and  of  the  lungs,  and  a  dark,  fluid 
condition  of  the  blood. 


ALKALOIDS    OF  UNKNOWN    CONSTITUTION. 

Of  the  numerous  alkaloids  whose  constitution  is  insufficiently 
known  to  permit  of  their  classification,  only  a  few  can  be  here  briefly 
considered  : 

Alkaloids  of  the  Aconites. — The  different  species  of  Aconitum 
contain  probably  a  number  of  alkaloids,  but  our  knowledge  of  them 
is  as  yet  extremely  imperfect.  The  substances  described  as  aconitin, 
lycoctonin,  napellin  are  impure.  It  appears,  however,  that  the  prin- 
cipal alkaloids  of  Aconitum  napellus  and  of  A.  ferox,  although  differ- 
ing from  each  other,  are  both  compounds  formed  by  the  union  of 
aconin,  C26H4iNOn,  with  the  radical  of  benzoic  acid  in  the  former, 
and  with  that  of  veratric  acid  in  the  latter. 

Aconitin  —  Acetylbenzoyl-aconin  —  C26H39(CH3.CO)  (C6H5.CO) 
NO n — the  principal  alkaloid  of  A.  napellus,  is  a  crystalline  solid, 
almost  insoluble  in  water,  and  very  bitter.  It  is  decomposed  by  IbO 
at  140°  (284°F.)  and  by  KHO  into  aconin  and  acetic  and  benzoic 
acids.  It  is  very  poisonous. 

Pseudo-aconitin — CseEUoNO^ — occurs  in  A.  ferox.  It  is  a  crys- 
talline solid,  having  a  burning  taste,  and  is  extremely  poisonous.  On 


492  MANUAL    OF    CHEMISTRY 

decomposition  by  H2O  at  140°  (284°  F.)  it  yields  aconin  and  veratric 
acid. 

Japaconitin — CeeHss^C^i — has  been  obtained  from  the  root  of  A. 
japanicum,  and  is  a  crystalline  solid  which  is  decomposed  by  alkalies 
into  benzoic  acid  and  japaconin,  C2eH4iNOio. 

The  color  reactions  described  as  characteristic  of  "aconitine" 
are  not  due  to  the  alkaloid. 

TOXICOLOGY. — Aconite  and  "aconitine"  have  been  the  agents  used 
in  quite  a  number  of  homicidal  poisonings. 

The  symptoms  usually  manifest  themselves  within  a  few  minutes; 
sometimes  are  delayed  for  an  hour.  There  is  numbness  and  tingling, 
first  of  the  mouth  and  fauces,  later  becoming  general.  There  is  a 
sense  of  dryness  and  of  constriction  in  the  throat.  Persistent  vom- 
iting usually  occurs,  but  is  absent  in  some  cases.  There  is  dimin- 
ished sensibility,  with  numbness,  great  muscular  feebleness,  giddi- 
ness, loss  of  speech,  irregularity  and  failure  of  the  heart's  action. 
Death  may  result  from  shock  if  a  large  dose  of  the  alkaloid  be  taken, 
but  more  usually  it  is  by  syncope. 

The  treatment  should  be  directed  to  the  removal  of  unabsorbed 
poison  by  the  stomach-pump,  and  washing  out  of  the  stomach  with 
infusion  of  tea  holding  powdered  charcoal  in  suspension.  Stimulants 
should  be  freely  administered. 

Alkaloids  from  other  Sources.  —  Ergotin  —  CsoH^^Os — and 
Ecbolin  are  two  brown,  amorphous,  faintly  bitter,  and  alkaline 
alkaloids  obtained  from  ergot.  They  are  readily  soluble  in  water  and 
form  amorphous  salts.  The  medicinal  preparations  known  as  ergotin 
are  not  the  pure  alkaloid. 

Colchicin  — CnHigNOs — occurs  in  all  portions  of  ColcMcum 
autumnale  and  other  members  of  the  same  genus.  It  is  a  yellowish  - 
white,  gummy,  amorphous  substance,  having  a  faintly  aromatic  odor 
and  a  persistently  bitter  taste.  It  is  slowly  but  completely  soluble  in 
water,  forming  faintly  acid  solutions.  It  forms  salts  which  are,  how- 
ever, very  unstable. 

Concentrated  HNO3,  or,  preferably,  a  mixture  of  H2S04,  and 
NaNO3,  colors  colchicin  blue-violet.  If  the  solution  be  then  diluted 
with  EbO,  it  becomes  yellow,  and  on  addition  of  NaHO  solution, 
brick -red. 

Veratrin  —  Veratrina,  U.  8.— CwHoNjOs— occurs  in  Veratrum 
officinalis=Asagrcea  officinalis,  accompanied  by  Sabadillin  —  C2oH2e- 
N2O5— Jervin  — C3oH46N2O3— and  other  alkaloids.  The  substance  to 
which  the  name  Veratrina,  U.  S.,  applies  is  not  the  pure  alkaloid, 
but  a  mixture  of  those  occurring  in  the  plant. 

Concentrated  H2SO4  dissolves  veratrin,  forming  a  yellow  solution, 
turning  orange  in  a  few  moments,  and  then,  in  about  half  an  hour, 


1  \wirwl-if 


PTOMAINS,  LEUCOMAI'NS,  TOXINS  AND  ANTITOXINS       493 


bright  carmine -red.  Concentrated  HC1  forms  a  colorless  solution 
with  veratrin,  which  turns  dark -red  when  cautiously  heated. 

Physostigmin  — Eserin  —  CisH^iNaC^  —  is  an  alkaloid  existing  in 
the  Calabar  bean,  Physostigma  venenosum.  It  is  a  colorless,  amor- 
phous solid,  odorless  and  tasteless,  alkaline  and  difficultly  soluble  in 
water.  It  neutralizes  acids  completely,  with  formation  of  tasteless 
salts.  Its  salicylate — Physostigminae  salicylas,  U.  S. — forms  short, 
colorless,  prismatic  crystals,  sparingly  soluble  in  water. 

Concentrated  H2S04  forms  a  yellow  solution  with  physostigmin 
or  its  salts,  which  soon  turns  olive -green.  Concentrated  HNOs  forms 
with  it  a  yellow  solution.  If  a  solution  of  the  alkaloid  in  H2SO4  be 
neutralized  with  NH4HO,  and  the  mixture  warmed,  it  is  gradually 
colored  red,  reddish -yellow,  green,  and  blue. 

Emetin  —  C28H4oN2Os — an  alkaloid  existing  in  ipecacuanha  which 
crystallizes  in  colorless  needles  or  tabular  crystals,  slightly  bitter  and 
acrid;  odorless,  and  sparingly  soluble  in  water. 

It  dissolves  in  concentrated  H2SO4,  forming  a  green  solution, 
which  gradually  changes  to  yellow.  With  Frohde's  reagent  it  gives 
a  red  color,  which  soon  changes  to  yellowish- green  and  then  to  green. 


PTOMAINS,  LEUCOMAINS,  TOXINS   AND   ANTITOXINS. 


The  name  ptomam,  derived  from  TTTUIUX.  (  "  that  which  has  fallen," 
i.e.,  a  corpse),  was  first  suggested  by  Selmi  in  1878  to  apply  to  a 
substance,  or  class  of  substances,  first  distinctly  recognized,  although 
not  isolated,  by  him,  which  are  produced  from  proteins  during  putre- 
faction, and  which  are  alkaloids  in  the  broader  sense  of  that  term. 
In  the  more  restricted  sense  in  which  the  term  "alkaloid"  is  now 
used  (p.  470),  many  of  the  best  known  ptomains  are  not  true  alka- 
loids, but  amins,  beta'ins,  oxyamins  or  diamins  (pp.  328-334,  422). 
On  the  other  hand,  many  ptomains  are  true  alkaloids.  Several  of 
the  superior  homologues  of  pyridin  (p.  460)  are  putrid  products. 
A  base,  CsHnN,  isomeric  with  collidin,  formed  during  putrefaction 
of  jelly-fish,  on  oxidation  yields  nicotinic  acid,  CsEUN^OOH),  which 
is  also  similarly  produced  from  nicotin  (p.  474),  and  also  forms  a 
chloroplatinate  and  an  iodomethylate  which  have  the  characteristic 
properties  of  the  like  compounds  produced  from  the  pyridin  bases 
(p.  459)  and  vegetable  alkaloids.  Other  basic  substances  obtained 
from  brown  cod  -liver  oil,  and  probably  formed  by  a  modified  putre- 
faction, are  hydropyridin  derivatives  (p.  461).  Among  these  are 
a  dihydrolutidin,  C7HnN,  a  dihydrocollidin,  C8Hi3N,  and  a  complex 

/  r\~\  T 

hydropyridic  oxyacid,  called  morrhuic  acid,  CsHsN,^  .COOH-     ^n" 


494  MANUAL    OF    CHEMISTRY 

dole  and  skatole,  products  of  putrefaction,  also  come  within  the 
definition  of  the  alkaloids. 

The  term  "ptomain,"  as  at  present  used,  therefore,  applies  to 
substances  of  several  different  chemical  classes,  in  some  of  which  the 
nitrogen  forms  a  part  of  a  heterocyclic  chain,  while  in  others  it  is 
in  a  lateral  chain  of  a  carbocyclic  compound,  and  in  still  others  in 
an  aliphatic  molecule.  A  ptomai'n  may  be  defined  as  a  basic  com- 
pound, containing  nitrogen,  produced  from  protein  material  by  the 
bacteria  which  cause  putrefaction.  The  use  of  the  name  in  referring 
to  similar  compounds  produced  by  other  processes,  or  by  other  bac- 
teria, is  improper  (see  below). 

Some  ptomams  are  strongly  alkaline  and  basic,  others  only  feebly 
so.  Some  are  liquid,  oily  and  volatile,  others  fixed  and  crystalline. 
Some  are  actively  poisonous,  others  practically  inert.  Some,  notably 
those  formed  in  the  earlier  stages  of  putrefaction,  contain  oxygen, 
others  are  made  up  of  carbon,  hydrogen  and  nitrogen.  Some  are 
very  prone  to  oxidation,  others  are  quite  stable. 

Several  methods  have  been  devised  for  the  more  or  less  complete 
separation  of  the  ptomams,  notably  from  vegetable  alkaloids,  none  of 
which,  however,  can  be  relied  upon  to  accomplish  the  object  com- 
pletely in  all  cases.  Breiger's  and  Gautier's  methods,  for  which  the 
student  is  referred  to  special  treatises,  are  the  most  elaborate.  Par- 
tial separation  can  be  effected  by  taking  advantage  of  the  fact  that 
the  oxalates  of  most  of  the  ptomams  are  soluble  in  ether,  in  which 
the  oxalates  of  most  of  the  vegetable  alkaloids  are  insoluble.  Or 
those  ptomams  which  are  diamins  can  be-  separated  by  the  benzoyl- 
chlorid  method.  In  dilute,  alkaline,  aqueous  solution  the  diamins 
form  crystalline,  insoluble  dibenzoyl  compounds  when  shaken  with 
benzoyl  chlorid.  This  is  purified  by  solution  in  alcohol  and  re- 
precipitation  by  dilution  with  water  (Udransky  and  Baumann). 

No  general  reaction  is  known  capable  of  distinguishing  the  pto- 
mams from  other  substances,  nor  is  one  to  be  expected,  in  view  of  the 
variation  in  their  chemical  constitution  above  referred  to.  Many  of 
the  ptomams  are  reducing  agents,  and  consequently  give  a  blue  color 
with  a  mixture  of  ferric  chlorid  and  potassium  ferricyanid  solutions 
(Brouardel  and  Boutmy's  reaction) ;  but  all  ptomams  do  not  reduce, 
and  some  vegetable  alkaloids,  as  morphin  and  veratrin,  do. 

It  was  feared  that,  as  alkaloidal  substances  in  many  respects 
resembling  those  of  vegetable  origin  are  produced  in  the  animal 
body,  not  only  after  death  but  during  life,  grave  doubts  would  be 
cast  upon  the  results  of  analyses  made  to  detect  the  presence  of 
poisonous  vegetable  alkaloids  in  the  cadaver  in  cases  of  suspected 
poisoning.  Such  fears  were  by  no  means  groundless,  as  there  is 
abundant  evidence  that  ptoma'ins  have  been  mistaken  for  vegetable 


PTOMAINS,    LEUCOMAINS,    TOXINS    AND    ANTITOXINS          495 


alkaloids  in  chemico- legal  analyses.  The  ptomains,  however,  as  well 
as  the  vegetable  alkaloids,  may  be  positively  identified  by  a  careful 
analysis,  based  upon  the  use,  not  of  a  single  reaction,  but  of  all 
known  reactions  for  the  alkaloid  in  question.  Therefore,  it  is  possible 
to  positively  predicate  the  existence  or  non-existence  of  a  given 
vegetable  alkaloid  in  a  cadaver,  but  it  can  only  be  done  after  a 
thorough  and  conscientious  examination  by  all  physiological  and 
chemical  reactions. 

The  term  "toxin"  was  first  used  by  Brieger,  and  applied  to  such 
of  the  ptomains  as  are  poisonous.  It  is  now,  however,  better  applied 
to  basic  substances  similar  chemically  to  the  ptomains,  but  produced 
by  pathogenic  bacteria,  either  in  living  bodies  or  in  appropriate 
culture  media. 

An  alkaloid,  many  of  whose  chemical  reactions  have  been  deter- 
mined, although  its  composition  is  unknown,  has  been  obtained  from 
the  internal  organs  and  dejecta  of  cholera  victims,  as  well  as  from 
cultures  of  the  comma  bacillus.  This  alkaloid,  when  administered 
to  animals,  causes  symptoms  of  poisoning  and  death. 

From  the  cultures  of  the  Koch-Eberth  typhus  bacillus  an  alkaloid 
has  been  isolated — Typhotoxin,  C?Hi7NO2 — which,  when  administered 
to  animals,  causes  paralysis,  copious  diarrhoea,  and  death. 

Tetanin — CisHso^CU — is  an  alkaloid  obtained  from  cultures  of 
a  bacillus  originating  from  a  wound  which  had  been  the  cause  of 
death  by  tetanus.  It  forms  a  deliquescent  chlorid,  and  a  very  soluble 
chloroplatinate.  The  free  base  or  its  chlorid,  when  injected  into 
mice  or  guinea-pigs,  causes  clonic  or  tonic  convulsions  of  the  greatest 
intensity,  which  terminate  in  death. 

Mytilitoxin — C6Hi5N02 — is  an  alkaloid  obtained  from  poisonous 
mussels,  which,  when  administered  to  animals  in  small  amount,  causes 
the  same  symptoms  as  are  produced  by  the  mussels. 

Another  class  of  poisons,  some  of  vegetable  and  others  of  animal 
origin,  have  the  properties  of  proteins,  and  appear  to  belong  to  the 
classes  of  globulins,  albumoses  or  peptones  (p.  497).  These  are 
known  as  toxalbumins,  and  among  them  are  included  abrin,  from 
jequirity  ( Abrus  precatorius  ) ,  ricin,  from  the  castor-oil  bean 
(Ricinus  communis) ,  phallin,  from  various  toadstools  ( Amanita) ;  the 
toxic  constituents  of  the  poisonous  secretions  of  serpents,  spiders,  and 
insects;  and  the  poisons  produced  by  certain  pathogenic  bacteria,  as 
those  of  diphtheria  and  cholera. 

Other  globulins  are  met  with  in  the  blood  of  animals,  which 
neutralize  the  action  of  the  toxalbumins,  and  which  are  more 
abundant  in  those  individuals  which  have  been  rendered  immune  to 
the  action  of  the  particular  toxalbumin  whose  action  they  modify. 
These  are  known  as  antitoxins. 


496  MANUAL    OF    CHEMISTRY 


Leucomains  (from  ACVKW  =  white  of  egg,  because  of  their  origin 
from  albumin)  are  nitrogenous,  basic  substances  which  are  produced 
in  the  bodies  of  animals  during  life  as  results  of  normal  chemical 
processes.  They  are  excreted  in  health,  and  if  retained  exert  dele- 
terious actions,  more  or  less  intense.  The  xanthiu,  or  purin,  bases 
(p.  356)  and  those  of  the  creatin  group  (p.  335)  are  leucomams,  and 
others  occur  in  the  urine. 

Poisonings  are  exogenous  or  endogenous  (p.  85).  In  exogenous 
poisonings  the  toxic  agent,  whether  it  be  mineral,  vegetable,  animal, 
or  synthetic,  is  introduced  into  the  body  from  without.  In  the 
popular  acceptation  of  the  term  all  poisonings  are  exogenous.  In 
endogenous  poisonings  the  toxic  agent,  always  organic,  either  a 
toxin,  a  toxalbumin  or  a  leucomam,  is  produced  in  the  body  of  the 
person  affected.  Endogenous  poisonings  are  called  diseases. 


PROTEINS  — ALBUMINOUS    COMPOUNDS  497 

SUBSTANCES    OF    UNKNOWN    CONSTITUTION. 
PROTEINS  —  ALBUMINOUS    COMPOUNDS . 

The  substances  of  this  class  are  never  absent  from  living  animal 
and  vegetable  cells,  to  whose  "life"  they  are  indispensable.  They  are 
frequently  referred  to  as  "proteids"  and  as  "albuminoids,"  terms 
which  are  now  used  in  a  more  restricted  sense,  to  apply  to  certain 
classes  of  proteins  (see  below). 

They  are  almost  all  uncrystallizable,  and  only  slightly  dialysable; 
some  are  soluble  in  pure  water,  others  only  in  presence  of  other  sub- 
stances, and  others  are  insoluble  in  water.  They  are  composed  of 
carbon,  hydrogen,  oxygen  and  nitrogen.  Most  of  them  also  contain 
sulfur,  some  contain  phosphorus,  others  iron;  and  all  contain  small 
quantities  of  mineral  salts.  Their  constitution  is  unknown,  and  no 
substance  has  as  yet  been  obtained  synthetically,  which  is  identical 
with  a  natural  protein,  although  substances  have  been  so  produced 
having  many  of  the  properties  of  the  gelatins  and  albumoses. 

A  classification  of  the  proteins  (irp^rdov  =  the  first) ,  based  upon 
their  constitution,  is  at  present  manifestly  impossible,  and  any  other 
classification  can  be  only  tentative.  For  a  provisional  classification 
some  of  the  proteins  arrange  themselves  naturally  in  well  defined 
groups  according  to  their  products  of  decomposition  and  their 
solubilities,  while  others,  of  quite  diverse  characters,  must  be  still 
arranged  in  the  miscellaneous  group  of  the  "albuminoids."  The 
classification  which  we  will  adopt  is  as  follows: 

I.  Albumens  —  Albuminous    Substances — (  Eiweisskorper   of  the 
Germans). 

a.  Albumins  —  soluble  in  pure  water;   coagulated  by  heat.    Serum 

albumin,  ovialbumin,  lactalbumin. 

b.  Globulins  —  insoluble  in  pure  water,  soluble  in  dilute  solutions 

of  neutral  salts;   coagulated  by  heat.     Myosin,  paraglobulin, 
fibrinogen,  oviglobulins. 

c.  Nucleoalbumens  —  almost  insoluble  in   pure   water,  or  in  solu- 

tions of  neutral  salts,  easily  soluble  in  slight  excess  of  alkalies; 
contain    phosphorus,    and   on   decomposition   by   pepsin   and 
hydrochloric  acid  yield  pseudonucleins.     Casein. 
The  above  are  distinguished  as  "native  albumens"  and  exist  in 
animal    tissues   and   fluids.     The   members   of    the   four   remaining 
groups  of  this  class  are  "derived  albumens,"  products  derived  from 
the  native  albumens: 

d.  Albuminates  —  insoluble  in  water  or  in  salt  solution,  except  in 

32 


498  MANUAL    OF    CHEMISTRY 

presence  of  acid  or  alkali;  derived  from  native  albumens  by 
the  action  of  acids  or  of  alkalies.  Acid -albumens,  alkali- 
albumens. 

e.  Albumoses — Propeptones — soluble  in  dilute   salt  solution,  pre- 

cipitated by  cold  HNO3,  redissolved  on  heating. 

f.  Peptones  —  very  soluble  in  water,  readily  dialysable,  not  coag- 

ulated by  heat,  nor  by  potassium  ferrocyanid  and  glacial  acetic 
acid. 

g.  Coagulated  albumens  —  insoluble  in  water,  or  in  salt  solutions; 

obtained  from  native  albumens  by  the  action  of  heat,  of  strong 
mineral  acids,  or  of  enzymes,  and  do  not  regenerate  the 
parent  protein.  Coagulated  albumins  and  globulins,  fibrin. 

II.  Proteids  —  on  decomposition  yield  an  albumen  and  some  other 

substance. 

a.  Haemoglobins  —  yield  an  albumin  or  globulin  and  a  crystalline 

pigment  or  chromogen. 

b.  Olycoproteids  —  yield   a  reducing   substance  (a  carbohydrate). 

Mucins,  amyloid,  etc. 

c.  Nucleoproteids  —  yield  a  true  nuclein,  which,  in  turn,  yields  a 

xanthin  base  on  decomposition.     Nucleohiston,  etc. 

III.  Albuminoids — proteins  not  included  in  one  of  the  above  classes. 

Keratins,  elastin,  collagen,  etc.,  etc. 

ALBUMENS  — ALBUMINOUS    SUBSTANCES. 

These  substances  are  odorless  and  tasteless,  generally  amorphous, 
although  certain  vegetable  albumens,  serum  albumin  and  an  egg 
albumin  have  been  obtained  in  crystalline  form.  They  do  not  dialyse, 
or  do  so  very  slowly.  Their  solutions  are  laevogyrous.  Their  solu- 
tions may  be  evaporated  at  temperatures  below  that  at  which  they 
coagulate,  when  they  remain  as  white,  or  yellow,  gummy  masses, 
which  redissolve  unchanged  in  water.  They  have  not  been  obtained 
entirely  free  from  mineral  salts.  The  native  albumens  suffer  the 
change  called  "coagulation"  when  their  faintly  acid  solutions  are 
heated.  They  are  thus  converted  into  white,  insoluble  "coagulated 
albumens,"  from  which  the  original  substance  cannot  be  regenerated. 
This  change  does  not  occur  in  alkaline  solutions,  and  only  partially 
in  neutral  solutions,  and  it  is  favored  by  the  presence  of  about  1  per 
cent,  of  sodium  chlorid.  The  "coagulation  temperature"  of  an 
albumen,  i.  e.,  the  temperature  at  which  coagulation  takes  place, 
varies  with  different  prote'fns,  and  serves  as  one  of  the  factors  for 
their  identification,  although  it  varies  within  certain  limits  with  the 
proportion  of  mineral  salts  present. 

Neither  the  constitution,  nor  even  the  composition  of  these  sub- 


ALBUMENS— ALBUMINOUS    SUBSTANCES  499 

stances  is  known,  yet  from  the  products  of  their  decomposition  it 
is  probable  that  they  are  highly  complex  amids  or  ureids.  They  all 
contain  carbon,  hydrogen,  nitrogen,  oxygen  and  sulfur,  and  some 
contain  phosphorus.  Their  molecules  contain  at  least  two  atoms  of 
sulfur,  as  a  part  only  of  this  element  goes  off  in  sulfid  combination 
on  boiling  with  caustic  alkalies,  the  remainder  only  on  fusion  with 
alkali  and  nitre.  As  the  proportion  of  sulfur  which  they  contain 
does  not  exceed  0.3  to  2.2  per  cent.,  they  have  large  molecular 
weights.  Their  percentage  composition  is:  C — 50.6  to  54.5;  H— 6.5 
to  7. 3;  N— 15.0  to  17.6;  S— 0.3  to  2.2;  P— 0.42  to  0.85;  O— 21.50 
to  23.50. 

Decompositions.  —  The  study  of  the  decompositions  of  the  pro- 
teins is  of  great  importance,  being  the  means  by  which  a  knowledge 
of  their  constitution  and  chemical  relations  must  be  sought  for. 

Oxidizing  agents  attack  the  molecule  profoundly,  yielding  prod- 
ucts far  removed  £rom  the  original  substance:  acids  and  aldehydes 
of  the  fatty  and  benzoic  series,  and  their  nitrils;  and  ketones,  hydro- 
cyanic acid,  amido- acids,  carbon  dioxid  and  ammonia.  On  heating 
with  baryta -water,  under  pressure  at  150°-250°,  an  odor  is  developed 
which  is  both  fascal  and  ammoniacal;  and  ammonia,  carbon  dioxid, 
and  oxalic  and  acetic  acids  are  formed,  along  with  a  mixture  of  amido- 
acids  as  the  principal  product.  These  amido -acids  belong  to  two 
classes:  (1)  leucins,  or  true  amido-acids  (p.  361),  and  (2)  leuceins, 
containing  two  atoms  of  hydrogen  less  than  the  corresponding  leucins, 
and  possibly  amido -acrylic  acids.  The  leucins  and  leuceins  appear 
to  result  from  the  hydrolysis  of  more  complex  substances  called 
glycoproteins,  because  of  their  sweet  taste,  not  to  be  confounded 
with  the  glycoproteids  referred  to  below.  On  fusion  with  caustic 
alkalies,  the  proteins  yield  ammonia,  mercaptan,  fatty  acids,  and 
amido-acids,  tyrosin,  indole,  and  skatole. 

When  boiled  with  mineral  acids,  or  better,  with  HC1  and  SnCb, 
the  albumens  are  decomposed  into  amido-acids,  hydrogen  sulfid, 
ethyl  sulfid,  ammonia,  and  a  series  of  nitrogen  bases.  Among  the 
last-named  are  four  well-defined  substances,  which  are  also  produced 
during  the  tryptic  digestion  of  albumen  in  the  intestine,  and  which, 
containing  six  carbon  atoms,  are  known  as  hexon  bases:  (1)  Lysin,  is 
diamido-caproic  acid  (p.  365).  It  is  non- crystalline,  soluble  in  water, 
dextrogyrous,  and  forms  two  chlorids  and  two  silver  compounds.  It 
forms  a  crystalline  compound  with  benzoyl  chlorid  in  presence  of 
alkali.  (2)  Ly satin,  or  lysatinin,  C6Hi3N3O2,  or  CeHnNsO,  a  homo- 
logue  of  creatin,  or  of  creatinin  (p.  336),  which  yields  urea  on  de- 
composition by  barium  hydroxid.  (3)  Arginin,  CcHi^iOsi  a  crys- 
talline base,  which  also  yields  urea  with  barium  hydroxid,  and  (4) 
Histidin,  C6H9N3O2,  a  crystalline  base,  soluble  in  water,  insoluble  in 


500  MANUAL    OF    CHEMISTRY 

alcohol  or  in  ether.     Lysin,  arginin,  and  histidin  are  also  produced 
by  decomposition  of  the  protamins. 

The  protamins,  first  obtained  from  the  melt  of  salmon  and  of 
other  fish,  by  extraction  with  sulfuric  acid  of  1-2%,  and  purification, 
are  the  most  important  of  the  decomposition  products  of  the  proteins, 
because  they  are  the  substances  most  nearly  related  to  the  parent 
substance,  whose  chemical  characters  are  definite.  They  have  been 
considered  as  being  the  simplest  of  the  proteins,  but  as  they  do  not 
yield  amido-acids  on  decomposition,  as  do  the  proteins,  they  are 
better  considered  as  nuclei  existing  in  the  proteins.  They  are  alka- 
line, basic,  nitrogenous  substances,  which  by  tryptic  digestion  yield, 
first  protamin-peptone,  and  afterwards  the  three  hexon  bases  above- 
mentioned.  Of  the  three  protamins  which  have  been  described  two 
are  probably  identical.  Salmin  and  clupein  (clupea=heYriug) ,  from 
the  melt  of  the  salmon  and  of  the  herring,  are  the  two  referred  to, 
Ci6H28Ng02  or  CaoHsTNnOe.  Sturin,  from  the  melt  of  the  sturgeon, 
probably  has  the  composition  CseHegNigOy.  The  protamins  produce 
precipitates  of  histon  (below)  in  ammoniacal  solutions  of  albumins  or 
of  primary  albumoses.  They  form  salts  with  acids,  which  are  soluble 
in  water,  insoluble  in  alcohol  and  ether.  They  are  partially  precipi- 
tated by  salting  with  NaCl.  They  give  the  biuret,  but  not  the  Millon 
reaction,  and  are  precipitated  from  their  neutral  solutions  by  phos- 
photungstic  and  picric  acids,  and  by  potassium  ferrocyanid. 

Histon  is  a  substance  obtained  from  the  red  corpuscles  of  goose 
blood,  and  from  the  protamins  as  above  indicated,  which  has  some 
resemblance  to  the  albumoses.  It  does  not  coagulate  by  heat.  With 
ammonia,  in  the  absence  of  salts,  it  forms  a  precipitate,  insoluble  in 
excess.  With  HNOs  it  forms  a  precipitate,  which  redissolves  on  heat- 
ing. The  name  "histon"  has  also  been  applied  to  other  substances, 
and  considerable  confusion  has  been  caused  thereby.  The  substance 
met  with  in  the  urine  in  leukaemia  and  called  histon  differs  from  the 
above  in  being  coagulable  by  heat. 

The  decomposition  of  proteins  by  proteolytic  enzymes  (7r/oa)Tctov= 
the  first,  A.vW=parting)  results  in  the  formation  of  albumoses,  pep- 
tones, and  amido-acids.  Those  changes  occur  in  the  processes  of 
digestion,  and  will  be  discussed  in  the  next  section. 

Putrefaction  is  the  decomposition  of  dead  protein  material  under 
the  influence  and  as  a  result  of  the  processes  of  nutrition  of  certain 
bacteria,  and  attended  by  the  evolution  of  more  or  less  fetid  products. 
In  order  that  it  may  occur  certain  conditions  are  necessary:  (1)  the 
presence  of  living  bacteria,  or  of  their  germs;  (2)  the  presence  of 
moisture;  (3)  a  temperature  between  5°  and  90°  (41°-194°  F.) ;  (4) 
an  atmospheric  condition  suitable  to  the  growth  of  the  bacteria. 
Some  of  the  several  species  of  bacteria  which  cause  putrefaction  are 


ALBUMENS  — ALBUMINOUS  SUBSTANCES          501 

aerobic,  i.  e.,  they  require  the  presence  of  air  for  their  development, 
while  others  are  anaerobic,  i.  e.,  they  thrive  best  in  the  absence  of 
oxygen.  Proteins  which  have  been  deprived  of  moisture,  either  by 
drying  or  by  the  action  of  dehydrating  agents,  such  as  strong  alcohol, 
do  not  enter  into  putrefaction  unless  water  is  supplied  to  them,  when 
the  process  proceeds  as  usual.  The  temperature  most  favorable  to 
putrefaction  is  about  40°  (104°  F.)  High  or  low  temperatures  arrest 
putrefaction  or  prevent  it,  the  former,  if  sufficiently  high,  perma- 
nently (if  the  material  be  protected  from  new  bacteria)  by  destroying 
the  vitality  of  the  bacteria;  the  latter,  even  if  extreme,  only  tempo- 
rarily, and  so  long  as  the  low  temperature  is  maintained. 

Putrefaction  may,  therefore,  be  prevented  either  (1)  by  the  action 
of  agents  or  substances  which  interfere  with  the  development  of  bac- 
teria (germicides  and  antiseptics);  (2)  by  the  exclusion  of  air;  (3) 
by  the  exclusion  of  water;  (4)  by  a  temperature  below  5°  (41°  F.)  or 
above  90°  (194°F.). 

Germicides  are  substances  or  agents  which  destroy  bacteria 
and  their  germs.  Mercuric  chlorid  and  heat  are  germicides. 

Antiseptics  are  substances  which  prevent  or  restrain  putre- 
faction. Antiseptics  are  either  germicides,  which  prevent  putrefac- 
tion by  destroying  the  organisms  which  cause  it,  or  are  agents,  which 
interfere  with  the  development  of  these  organisms  without  destroying 
their  vitality.  The  salts  of  aluminium  are  antiseptic  by  reason  of 
their  chemical  action  on  the  proteins,  although  their  germicidal 
powers  are  slight, 

Deodorizers,  or  air  purifiers,  are  substances  which  destroy  the 
odorous  products  of  putrefaction. 

Disinfectants  are  substances  which  restrain  infectious  dis- 
eases by  destroying  or  removing  their  specific  poisons. 

Putrefaction  is  attended  by  the  breaking  down  and  liquefaction  of 
the  material  if  it  be  solid ;  or  its  clouding  and  the  formation  of  a  scum 
upon  the  surface  if  it  be  liquid.  The  products  of  putrefaction  vary 
with  the  conditions  under  which  it  occurs.  The  most  prominent  are: 
(1)  inorganic  products  such  as  N,  H,  £[28,  NHs,  and  simple  organic 
compounds,  such  as  C(>2  and  hydrocarbons;  (2)  acids  of  the  fatty 
series  in  great  abundance,  and  acids  of  the  oxalic  and  lactic  series; 
(3)  non-aromatic  monamins  and  diamins,  such  as  trimethylamin, 
putrescin,  and  certain  of  the  ptomains;  (4)  aromatic  products,  among 
which  are:  (a)  phenols,  such  as  tyrosin,  oxyaromatic  acids,  phenol, 
and  cresol;  (&)  phenylic  derivatives,  such  as  phenyl  acetic  and  phe- 
nyl  propionic  acids;  (c)  indole,  scatole,  scatole- carbonic  acid,  etc.; 
(d)  ptomains  of  undetermined  constitution,  but  belonging  to  the 
aromatic  series;  pyridin  derivatives. 

Under  certain  imperfectly  defined  conditions,  buried  animal  matter 


502  MANUAL    OF    CHEMISTRY 

is  converted  into  a  substance  resembling  tallow,  and  called  adipocere, 
which  consists  chiefly  of  ammonium  palmitate,  stearate,  and  oleate, 
calcium  phosphate  and  carbonate,  and  an  undetermined  nitrogenous 
substance. 

There  occurs  a  decomposition  of  vegetable  tissues  under  the  in- 
fluence of  warmth  and  moisture,  which  is  known  as  eremacausis, 
differing  from  putrefaction  in  that  the  substances  decomposed  are 
the  carbohydrate  instead  of  the  azotized  constituents,  and  in  the 
products  of  the  decomposition,  there  being  no  fetid  gases  evolved 
(except  there  be  simultaneous  putrefaction),  and  the  final  product 
•is  a  brownish  material  (humus  or  ulmin). 

General  Reactions. — The  albumens  all  respond  to  a  great  number 
of  general  reactions,  which  maybe  classified  in  three  groups:  I.  Color 
reactions;  II.  Precipitations  in  an  insoluble  combination;  alkaloidal 
reactions;  III.  Precipitations  in  a  form  which  permits  of  easy  reso- 
lution in  the  primitive  form. 

I.  (1)  A  purple -red  color  when  warmed  to  70°   (158°  F.)  with 
Millon's  reagent.     The  reagent  is  made  by  dissolving,  by  the  aid  of 
heat,  1  pt.  Hg  in  2  pts.  HNO3  of  sp.  gr.  1.42,  diluting  with  2  vols. 
H2O,  and  decanting  after  24  hours.     (2)  A  yellow  color  with  HNOa; 
changing  to  orange  with  NEUHO  (xanthoproteic  reaction).     (3)  A 
purple  color  with  Pettenkofer's  test  (p.  527).     (4)  With  a  drop  or 
two  of   cupric  sulfate  solution  and  liquor  potassa3:    a  violet   color 
(biuret  reaction).     (5)  A  solution  of  an  albumen  in  excess  of  glacial 
acetic   acid  is    colored   violet   and   rendered  faintly   fluorescent    by 
concentrated  IbSO*  (Adamkiewicz'   reaction).      (6)   With  Frb'hde's 
reagent  (p.  485)  solid  albumens  give  a  fine  blue  color.     (7)  If  an 
alkaline  solution  of  an  albumin  or  a  peptone  be  mixed  with  an  al- 
kaline solution  of   diazobenzosulfonic  acid  a  red -brown  or  orange 
color  is  produced.      If  powdered  Zn  or  sodium  amalgam  be  added 
the  color  becomes  a  brilliant  red  (Petri's  reaction).     (8)  Add  to  the 
albuminous  liquid  two  drops  of  an  alcoholic  solution  of  benzoic  alde- 
hyde, then  some  H2S04  diluted  with  an  equal  bulk  of  H20,  and  finally 
a  drop  of  ferric  sulfate  solution:   a  dark  blue  color  is  produced  either 
immediately  on  warming,  or  slowly  in  the  cold  (Reichl's  reaction). 
(9)  Albumins  dissolve  in  boiling  concentrated  HC1  (sp.  gr.  1.19) 
with  a  violet-blue  color,  and  coagulated  albumins  are  similarly  colored 
by  boiling  HC1.    The  color  is  the  more  distinct  the  purer  the  albu- 
min.    The  reaction  may  be  applied  to  the  albumin  coagulated  from 
urine,  after  collection  on  a  filter,  and  washing  with  water,  alcohol,  and 
ether  (Liebermann's  reaction). 

II.  The  albumens  are  precipitated  in  an  insoluble  form  by:  (1)  The 
concentrated  mineral  acids,  notably  HNOs;    (2)  by  potassium  ferro- 
cyanid  in  presence  of  acetic  acid;    (3)  by  certain  organic  acids  in  the 


ALBUMENS  — ALBUMINOUS  SUBSTANCES          503 

presence  of  concentrated  solutions  of  NaCl  or  Na2SO4;  (4)  by  tannin 
in  acid  solution;  (5)  by  tungstates,  or  phosphomolybdic  or  phospho- 
tungstic  acid;  (6)  by  potassium  iodhydrargyrate,  or  potassium  iodo- 
bismuthate  in  acid  solution;  (7)  by  solutions  of  the  salts  of  Pb,  Cu, 
Ag,  Hg,  U;  (8)  by  chloral,  picric  acid,  salicyl-sulfonic  acid,  phenol 
or  trichloracetic  acid. 

III.  Some  of  the  albumens  are  precipitated  in  a  form  capable  of 
resolution  by  solutions  of  certain  salts,  notably  by  the  sulfates  and 
phosphates  of  the  alkaline  metals,  ammonium  and  magnesium. 

The  general  characters  of  the  several  groups  of  albumens  are  as 
follows  : 

Albumins — are  soluble  in  pure  water,  and  are  not  precipitated 
therefrom  by  a  small  quantity  of  acid  or  of  alkali,  but  are  precipi- 
tated by  excess  of  mineral  acids  and  by  metallic  salts.  They  are 
coagulated  by  heat  in  the  presence  of  neutral  salts,  but  not  by  a 
boiling  temperature  in  their  absence.  At  30°  the  addition  of  solid 
NaCl  or  MgSCU  to  saturation  (salting)  does  not  cause  their  precipi- 
tation until  after  the  addition  of  acetic  acid,  when  they  separate. 
Salting  their  solutions  with  (NlUhSO*  to  saturation  causes  their 
complete  precipitation.  (See  Blood,  Urine,  Milk  in  next  section;  egg 
albumen  below.) 

Globulins — are  insoluble  in  pure  water,  and  precipitated  from 
their  solutions  by  dilution  with  a  large  quantity  of  water;  soluble  in 
dilute  solutions  of  neutral  salts,  or  in  presence  of  slight  excess  of  acid 
or  of  alkali,  but  precipitated  from  the  latter  solutions  by  neutrali- 
zation; precipitated  from  their  alkaline  solutions  by  CO2,  but  redis- 
solved  by  excess  of  the  gas.  Their  neutral  solutions  are  partly  or 
completely  precipitated  by  salting  with  NaCl  or  MgSO*,  completely 
by  salting  with  (NEUhSCU.  They  are  coagulated  by  heat.  They 
contain  a  smaller  proportion  of  sulfur  than  the  albumins  (A=1.6- 
2.2%,  G=about  1%).  (See  Blood,  Urine,  Milk  in  next  section.) 

Egg-albumen — The  "white  of  egg"  consists  of  a  yellowish  fluid, 
enclosed  in  a  delicate  network  of  connective  tissue  (keratin).  The 
fluid  portion,  separated  from  the  membrane  by  beating  and  filtration 
through  muslin,  is  alkaline,  sp.  gr.  1.045,  and  of  very  complex  com- 
position; containing  850-880  p/m  water,  100-130  proteins,  7  salts, 
and  traces  of  fat,  lecithins,  cholesterol  and  a  carbohydrate.  The  pro- 
teins of  white  of  egg  are  at  least  five  in  number:  67  of  the  100-130 
p/m  above  referred  to  consist  of  two  globulins,  coagulated  at  57.5° 
and  67°,  partly  precipitable  by  dilution  with  water,  completely  by 
salting  with  MgSO4;  three  albumins,  differing  in  coagulation  tem- 
peratures; 67°,  72°,  and  82°,  and  in  specific  rotary  power:  [a]D= 
-25.8°,  -34.2°,  and  -42.5°,  all  of  which  are  lower  than  the  value  of 
[a]D  for  serum  albumin,  -62.6°  to  -64.6°.  These  albumins  also  differ 


504  MANUAL    OF    CHEMISTRY 

from  serum  albumin  in  that  they  appear  in  the  urine  when  injected 
into  the  circulation,  which  serum  albumin  does  not  do.  A  crystalline 
albumin  has  been  obtained  from  white  of  egg  by  removal  of  the 
globulins  by  partial  salting  with  (NEUhSOi,  slow  evaporation  of  the 
solution  at  the  ordinary  temperature,  and  recrystallization.  The 
carbohydrate  above  referred  to  appears  to  exist  in  the  form  of  a 
glycoproteid  (p. 505  ),  containing  15%  of  carbohydrate,  and  1.18%  of 
sulfur.  Ovimucoid  is  a  pseudo-peptone,  constituting  about  10%  of  the 
proteins  of  white  of  egg.  It  is  not  precipitated  by  mineral  acids,  ex- 
cept phosphotungstic  acid,  and  is  obtained,  after  removal  of  globulins 
and  albumins  by  heat  and  acetic  acid,  by  precipitation  with  alcohol. 

Nucleoalbumens — are  widely  disseminated  in  animal  and  vege- 
table organs  rich  in  cells,  and  also  in  solution  in  fluids.  They  con- 
tain phosphorus  and  traces  of  iron.  They  behave  as  acids,  are 
almost  insoluble  in  water,  soluble  in  very  weak  alkaline  solutions, 
very  sparingly  soluble  in  neutral  salt  solutions,  and  are  not  coagu- 
lated by  heat.  Their  most  characteristic  property  is  that,  upon 
peptic  digestion  they  yield  para-  or  pseudo-nucleins  (p.  507).  They 
resemble  the  nucleo-proteids,  and  the  glycoproteids,  but  differ  from 
the  former  in  that  they  yield  no  xanthin  bases  on  decomposition,  and 
from  the  latter  in  that  they  yield  no  reducing  substances  under  like 
conditions. 

The  lecithalbumens  resemble  the  nucleoalbumens  in  that  they 
contain  phosphorus  and  do  not  yield  xanthin  bases,  but  on  decom- 
position they  yield  lecithins  (p.  319).  They  remain  as  insoluble 
residues  of  the  peptic  digestion  of  glandular  tissues,  and  of  the 
ovivitellin  of  the  yolk  of  egg. 

Albuminates. — Native  albumens  dissolve  without  change  in  dilute 
acid  or  alkaline  solutions,  and  may  be  recovered  therefrom,  but  with 
concentrated  acids  or  alkalies,  or  by  long  contact  with  dilute  solu- 
tions, derived  products  are  formed,  with  loss  of  nitrogen,  and  even  of 
sulfur.  These  acid-  or  alkali-albumens  are  jelly-like  in  consistency, 
soluble  in  warm  water,  almost  insoluble  in  cold  water,  easily  soluble 
in  presence  of  a  trace  of  acid  or  of  alkali,  and  precipitable  from  these 
solutions  by  neutralization,  but  not  coagulated  by  heat.  Whether 
acid-  and  alkali -albumens  are  distinct  substances,  or  one  and  the 
same,  is  doubtful.  Syntonin  is  a  form  of  acid -albumen  produced 
from  myosin  by  the  action  of  HC1  of  2  p/m  by  prolonged  contact, 
or  by  short  contact  of  the  same  acid  in  presence  of  pepsin.  If 
concentrated,  it  is  jelly-like  in  consistency,  but  differs  from  other 
acid -albumens  in  being  insoluble  in  NaEfePC^  solution,  and  soluble 
in  CaH2(>2  solution. 

Albumoses  and  peptones  will  be  considered  in  the  next  section, 
under  "Digestion." 


PROTEIDS  505 

Coagulated  Albumens — are  produced  from  some  of  the  previously 
described  proteins,  either:  (1)  by  heat;  (2)  by  alcohol  in  presence  of 
neutral  salts.  If  the  contact  with  alcohol  be  of  short  duration  the 
protein  is  precipitated,  and  may  be  redissolved;  if  the  contact  be 
prolonged  it  is  coagulated  and  permanently  altered;  (3)  by  long 
agitation  of  their  solutions;  (4)  by  the  action  of  certain  enzymes. 
But  little  is  known  of  the  nature  of  the  change,  or  of  the  chemical 
characters  of  the  products.  These  are  white  substances  (fibrin,  hard- 
boiled  white  of  egg)  insoluble  in  water,  or  in  solutions  of  neutral 
salts,  or  in  dilute  acids  or  alkalies  at  the  ordinary  temperature. 
They  are  soluble  by  conversion  into  acid-  or  alkali- albumens  by 
concentrated  acids  or  alkalies,  or  by  the  same  when  dilute  if  aided 
by  heat.  They  are  acted  upon  by  digestive  enzymes  and  converted 
into  albumoses  and  peptones.  Although  coagulated  albumens  are 
usually  artificial  products,  except  fibrin  naturally  coagulated,  proteins 
having  similar  properties  are  met  with  in  the  liver  and  in  other 
glands. 

PROTEIDS. 

A  proteid  is  a  protein  which  is  capable  of  being  decomposed  into 
an  albumen  and  some  other  substance. 

Haemoglobins — yield  an  albumen  and  a  crystalline  pigment,  or 
chromogen  (see  "Blood,"  in  the  next  section). 

Glycoproteids  —  on  heating  with  dilute  mineral  acids,  yield  an 
albumen  and  a  substance  capable  of  reducing  Fehling's  solution, 
but  no  xanthin  base  (distinction  from  nucleo-proteids).  They  are 
divisible  into  two  classes:  (a)  those  which  contain  no  phosphorus, 
and  (&)  those  which  contain  phosphorus.  The  first  class  contains 
the  true  mucins,  the  chondroproteids,  and  the  mucoids.  The  true 
mucins  occur  in  connective  and  epithelial  tissues,  and  in  mucous 
secretions.  They  form  slimy  solutions  in  water,  from  which  they 
are  precipitated  by  acetic  acid,  and  are  not  soluble  in  excess  of  the 
precipitant.  When  dry  they  are  white  or  grayish,  soluble  in  much 
water,  to  an  acid  solution,  which  is  not  coagulated  by  heat.  They 
are  not  acted  upon  by  the  gastric  juice.  They  contain  no  sulfur. 
When  heated  with  dilute  mineral  acids  they  yield  acid -albumen  and 
a  hexose  called  mucose.  The  chondroproteids,  on  decomposition 
by  heating  with  dilute  mineral  acids  yield  an  albumen  and  an  ester- 
sulfuric  acid,  called  chondroitinsulfuric  acid,  which  contains  a  car- 
bohydrate, and  which  is  capable  of  precipitating  the  albumens.  The 
principal  members  of  the  group  are:  chondromucoid,  a  constituent 
of  cartilage,  and  amyloid,  a  pathological  product  met  with  in  the 
kidney,  liver  and  spleen  in  "amyloid  degeneration."  It  appears  in 
granules,  resembling  those  of  starch  in  gross  appearance  (hence  the 


306  MANUAL    OF    CHEMISTRY 

name),  amorphous,  white,  insoluble  except  in  concentrated  acids  and 
alkalies,  not  dissolved  by  the  gastric  juice,  colored  red -brown  by 
iodin,  changing  to  violet  on  addition  of  H2S04,  colored  bright -red 
by  eosin,  rose -red  by  anilin  violet,  and  red  by  anilin  green.  The 
mucoids  are  non-phosphorized  glycoproteids  not  belonging  to  one 
of  the  previous  groups.  They  exist  in  the  submaxillary  saliva, 
intestinal  mucus,  vitreous,  white  of  egg  and  umbilical  cord.  They 
are  distinguished  from  the  true  mucins  by  not  being  precipitated  by 
acetic  acid. 

Phospho-glycoproteids — are  substances  rich  in  phosphorus,  which 
on  decomposition  by  dilute  acids  yield  a  reducing  substance  (differ- 
ence from  nucleoalbumens),  but  no  xanthin  bases  (difference  from 
nucleoproteids).  But  two  substances  of  this  class  have  been  de- 
scribed: icthulin,  from  the  kidneys  of  the  carp,  and  helico-proteid, 
from  the  mucous  secretion  of  the  snail. 

Nucleoproteids  —  are  substances  intimately  connected  with  the 
processes  of  cell -life,  which  occur,  along  with  some  of  their  compo- 
nents (nucleins)  in  glandular  organs,  liver,  thymus,  kidney,  etc.,  in 
the  melt  of  fish  and  the  spermatozoa  of  higher  animals,  in  pus,  in 
the  yeast-plant,  etc.,  existing  principally  in  the  cell-nuclei,  but  also 
in  the  protoplasm.  They  are  weak  acids,  insoluble  in  water,  but 
forming  soluble  compounds  with  alkalies.  They  are  rich  in  phos- 
phorus, of  which  they  contain  0.5-1.6%.  They  are  decomposed  by 
heating  with  dilute  acids,  or  by  peptic  digestion,  into  an  albumen, 
probably  a  globulin,  and  a  true  nuclein.  By  further  decomposition 
the  nuclein  is  decomposed  into  a  further  quantity  of  albumen  and  a 
nucleic  acid,  and  by  still  further  action  the  nucleic  acid  is  decomposed 
into  a  xanthin  base  (pp.  356-359),  a  carbohydrate  and  a  phosphorus 
acid,  usually  metaphosphoric  acid.  The  best  known  of  the  nucleo- 
proteids is  nucleohiston,  obtained  from  the  thymus  of  the  calf.  It 
contains  3.025%  of  phosphorus  and  0.701%  of  sulfur.  Its  solutions 
are  decomposed  by  heat,  with  separation  of  a  coagulated  albumen,  and 
it  is  also  decomposed  by  HC1  of  8  p/m,  with  separation  of  an  albumen 
which  dissolves  in  the  acid,  which  differs  from  other  albumens  in 
being  insoluble  in  excess  of  ammonia,  and  which  has  been  called 
histon.  In  both  cases  a  nuclein  is  the  other  product  of  decompo- 
sition. Nucleohiston  is  soluble  in  very  dilute  alkaline  solutions, 
from  which  it  is  precipitated  by  acetic  acid,  and  is  insoluble  in  excess 
of  the  acid.  It  is  also  precipitated  by  alcohol,  but  not  by  salting 
with  MgS(>4.  It  is  supposed  to  play  an  important  part  in  the 
coagulation  of  the  blood  (p.  553). 

Nucleins.  —  The  true  nucleins,  on  decomposition  by  acids,  yield 
albumens  and  nucleic  acids,  which  in  turn  yield  xanthin  bases.  They 
are  obtained  as  insoluble  or  difficultly  soluble  residues  on  peptic 


ALBUMINOIDS  507 

digestion  of  the  nucleoproteids.  They  contain  5%  and  over  of  phos- 
phorus, which  on  their  decomposition  is  converted  into  metaphos- 
phoric  acid,  and  also  traces  of  iron.  By  alkalies  they  are  decomposed 
into  albumens  and  nucleic  acids.  They  are  colorless,  amorphous, 
very  sparingly  soluble  in  water,  moderately  soluble  in  dilute  alkaline 
solutions,  insoluble  in  alcohol  and  ether,  not  disolved  by  gastric  juice 
or  by  dilute  acids,  and  behave  as  rather  strong  acids.  They  give 
the  biuret  and  the  Millon  reactions,  and  readily  take  up  basic  pig- 
ments from  aqueous  or  alcoholic  solution. 

Pseudo-,  or  para-nucleins  —  differ  from  the  true  nucleins  in 
yielding  no  xanthin  bases  on  decomposition.  They  are  obtained  as 
sparingly  soluble  residues  on  peptic  digestion  of  nucleoalbumens  or 
phospho-glycoproteids.  They  are  rich  in  phosphorus,  which  they  also 
give  off  as  metaphosphoric  acid.  They  are  amorphous,  insoluble  in 
water,  alcohol  and  ether,  soluble  in  dilute  alkaline  solutions,  insolu- 
ble in  dilute  acids.  Some  of  them,  on  decomposition  by  acids,  yield 
reducing  substances,  but  those  best  known  do  not. 

Nucleic  acids  —  are  obtained  by  decomposition  of  nucleins  by 
alkalies.  On  decomposition  they  yield  a  xanthin  base,  a  carbohy- 
drate and  metaphosphoric  acid.  There  is  at  least  one  acid  cor- 
responding to  each  of  the  four  bases,  xanthin,  hypoxanthin,  guanin 
and  adenin,  and  probably  others  containing  two  of  these  bases.  They 
also  differ  in  the  nature  of  the  carbohydrate  which  they  contain, 
which  in  some  is  a  hexose,  in  others  a  pentose,  and  still  others  con- 
tain both  hexoses  and  pentoses.  They  are  all  amorphous,  white, 
acid,  almost  insoluble  in  alcohol  or  in  ether,  and  readily  soluble  in 
dilute  alkaline  solutions.  They  give  neither  the  biuret  nor  the 
Millon  reaction.  They  form  precipitates  in  solutions  of  albumens,  by 
regeneration  of  nucleins.  The  guanyl  acid,  obtained  from  pancreas, 
yields  36  %  of  guanin,  30  %  of  pentose,  and  18  %  of  phosphoric 
anhydrid. 

ALBUMINOIDS. 

This  is  a  miscellaneous  collection  of  those  proteins  which  are 
neither  albumens  nor  proteids.  About  the  only  character  which 
they  have  in  common  is  that  they  are  insoluble  in  the  solvents  of 
the  members  of  the  preceding  groups.  They,  for  the  most  part, 
occur  in  connective  tissues,  cartilage,  bone,  epidermic  tissues,  etc. 

Keratins  —  occur  in  epidermis,  hair,  nails,  horn,  hoofs,  feathers, 
tortoise-shell,  and  other  epidermic  tissues,  in  brain  and  nerve  tissue 
(neuro- keratin)  and  in  the  membrane  of  eggs.  They  vary  in  com- 
position, containing  from  1.6  %  to  5.0  %  of  sulfur,  the  maximum  of 
that  element  being  found  in  human  hair,  which  yields  a  sulfid  even 
to  boiling  water,  a  fact  utilized  in  lead  and  other  metallic  hair- 


508  MANUAL    OF    CHEMISTRY 

dyes,  which  form  colored  sulfids.  There  are  several  keratins,  which 
are  amorphous,  insoluble  in  water,  alcohol,  ether,  acids,  gastric  juice 
or  trypsin,  slowly  soluble  in  alkalies.  When  heated  with  water 
under  pressure  to  150°-200°,  they  dissolve,  but  do  not  gelatinize. 
Their  products  of  decomposition  are  similar  to  those  of  the  albu- 
mens, except  that  their  sulfur  is  more  easily  split  off.  They  give 
the  xauthoproteic  and  Millon  reactions,  sometimes  imperfectly. 

Elastin  —  occurs  in  elastic  tissues,  notably  the  ligamentum  nu- 
chae.  Its  sulfur  content  is  small,  0.27-0.66  %.  When  dry,  it  is  a 
yellow  powder,  insoluble  in  the  usual  solvents,  only  slowly  soluble 
in  boiling,  concentrated  caustic  potash,  or  concentrated  sulfuric  acid, 
soluble  in  hot  HC1.  When  heated  with  water  under  pressure,  or  by 
boiling  with  dilute  acids,  or  by  the  action  of  proteolytic  enzymes,  it 
is  decomposed  into  two  albumoses,  both  soluble  in  water,  and  dif- 
fering from  each  other  in  that  one,  protoelastose,  is  precipitated  by 
heat,  by  mineral  acids,  or  by  acetic  acid  and  ferrocyanid,  while  the 
other,  deuteroelastose,  is  not  so  precipitated. 

Collagen  —  Ossein  —  is  the  principal  constituent  of  the  fibers  of 
connective  tissue,  bones,  tendons  and  cartilage.  When  dry  it  is 
amorphous,  yellow,  hard,  insoluble  in  water,  dilute  acids  or  alka- 
lies. Macerated  in  dilute  acids  it  swells  and  become  pliable.  If 
previously  heated  to  70°  with  water,  it  is  soluble  in  the  gastric  and 
pancreatic  juices.  Its  products  of  decomposition  are  similar  to  those 
of  the  albumens,  but  it  yields  a  large  proportion  of  glycocoll,  which 
is  not  produced  from  the  true  albumens.  In  putrefaction  no  tyrosin, 
indole  or  skatole  is  formed.  The  tannins  combine  with  collagen  to 
form  a  tough,  hard,  imputrescible  material  which  constitutes  leather. 
When  boiled  with  dilute  acids,  or  when  heated  with  water  under  pres- 
sure, collagen  is  converted  into  gelatin  or  glue.  This  is  a  translucent 
material,  white  to  brown,  according  to  purity,  which  swells,  but  does 
not  dissolve  in  cold  water,  soluble  in  hot  water,  the  solution  gelatin- 
izing, i.e.,  forming  a  jelly-like  mass,  on  cooling,  or  if  more  con- 
centrated, the  solution  on  cooling  becomes  solid  and  hard  (glue). 
Gelatin  gives  the  biuret  reaction,  but  not  the  Millon  reaction.  It  is 
dissolved  by  gastric  and  pancreatic  juices,  probably  with  formation 
of  two  albumoses,  and  later,  of  peptone. 

Other  albuminoids  are:  Reticulin,  from  connective  tissues,  intes- 
tinal mucous -membrane,  liver,  spleen,  kidney,  lungs;  contains  phos- 
phorus. Chitin  constitutes  the  albuminoid  portion  of  the  hard  parts 
of  insects.  Spongin  is  the  principal  organic  constituent  of  sponges.. 
Conchiolin  is  the  albuminoid  of  the  shells  of  molluscs.  Fibroin  and 
sericin  are  the  principal  constituents  of  raw -silk.  Kornein  is  ob- 
tained from  coral  zoophytes.  Ichthylepidin  exists,  along  with  col- 
lagen, in  fish -scales. 


VEGETABLE    PROTEINS  509 

VEGETABLE   PROTEINS. 

Proteins  exist  in  the  liquids,  and  particularly  in  the  reproductive 
organs  of  plants.  They  resemble  the  animal  proteins  in  their  general 
properties,  and  in  the  products  of  their  decomposition  by  dilute  acids 
and  by  digestive  enzymes.  They  have  been  classified  into  four 
groups:  (1)  vegetable  albumins;  (2)  vegetable  globulins;  (3)  gluten 
proteins;  and  (4)  vegetable  caseins. 

The  classes  of  vegetable  albumins  and  vegetable  globulins  are 
not  sharply  differentiated,  as  the  latter  are  not  entirely  insoluble  in 
pure  water.  Both  are  coagulated  by  heat.  The  effect  of  sodium 
chlorid  upon  solutions  of  vegetable  globulins  also  varies  with  the 
proportion  of  salt  present ;  a  small  amount  causing  a  precipitate, 
which  redissolves  in  a  larger  proportion,  and  is  again  precipitated  by 
a  further  addition  of  salt.  Wheat  flour  contains  0.26  to  0.30%  of 
protein  coagulable  by  heat,  and  1.55  to  1.90%  of  protein  material 
not  so  coagulable.  Conglutin,  a  protein  obtained  from  the  lupines 
and  from  almonds,  has  most  nearly  the  characters  of  the  globulins, 
"being  soluble  in  salt  solutions  of  5  to  10  per  cent.,  and  precipitable 
therefrom  by  dilution  with  water.  A  similar  globulin  accompanies 
legumin  in  peas. 

Gluten  is  the  protein  material  existing  in  wheat  and  other  cereals, 
which  remains  insoluble  and  forms  a  soft,  but  tough,  elastic  paste, 
when  the  flour  is  kneaded  in  a  stream  of  water  upon  a  fine  seive. 
It  constitutes  about  78%  of  the  total  proteins  of  wheat.  It  is  made 
up  of  at  least  four  factors.  On  extracting  it  with  alcohol,  gluten 
casein  (below)  remains  as  an  insoluble  residue;  and  the  solution  con- 
tains gliadin,  mucedin,  and  gluten-fibrin,  which  differ  from  each 
other  principally  in  their  solubility  in  water  and  in  alcohol  of  vary- 
ing degrees  of  concentration.  Maize  also  contains  a  protein  called  zein, 
which  resembles  gluten -fibrin,  but  is  not  identical  with  it. 

The  vegetable  caseins  are  insoluble  in  pure  water  and  in  salt 
solutions,  but  are  readily  soluble  in  dilute  acids  or  alkalies,  and  are 
coagulated  by  heat.  Legumin  is  a  vegetable  casein  existing  in  peas, 
beans,  and  other  leguminous  seeds.  Gluten  casein  occurs  in  cereals. 
Aleurone  corpuscles,  or  protein  granules  are  minute  rounded  masses 
which  accompany,  and  sometimes  replace  starch  granules  in  various 
grains  and  nuts,  notably  in  Brazil  nuts.  They  resemble  starch  - 
granules  in  shape  and  appearance,  but  are  colored  brown  by  iodin, 
and  contain  9.36%  of  nitrogen.  They  contain  more  than  one  protein, 
probably  three,  one  of  which  is  a  vegetable  casein  which  may  be  ob- 
tained from  Brazil  nuts  in  the  form  of  well-defined  crystals,  by 
treatment  of  the  finely -divided  tissue  with  ether,  and  then  with 
water,  from  which  the  crystals  are  deposited  by  subsidence. 


510  MANUAL    OF    CHEMISTRY 


PHYSIOLOGICAL   CHEMISTRY. 

The  adjective  "physiological"  is  here  used  in  its  proper  sense. 
Physiology  ( </>vo-toAoyos=discoursing  of  nature)  is  defined  as  "the  sum 
of  scientific  knowledge  concerning  the  functions  of  living  things." 
Chemistry  has  been  defined  as  "that  branch  of  science  which  treats 
of  the  composition  of  substances,  their  changes  in  composition,  and 
the  laws  governing  such  changes."  Therefore  physiological  chem- 
istry has  to  do  with  the  composition  and  changes  in  composition  of 
living  things,  whether  they  be  in  a  normal  or  in  an  abnormal  condition. 
The  medical  tendency  to  distinguish  between  "physiological"  and 
"  pathological "  chemistry,  the  former  being  considered  as  a  branch  of 
physiology,  and  the  latter  as  a  division  of  pathology,  besides  in- 
volving a  solecism,  is  undesirable  for  four  reasons  :  (1)  The  methods 
by  which  tissues  and  fluids  are  obtained  from  otherwise  normal  ani- 
mal bodies  for  investigation  are  frequently  such  that  they  establish  a 
pathological  condition,  and  the  extent  to  which  the  material  so 
obtained  is  thus  modified  from  the  normal  must  always  be  taken  into 
consideration  in  interpreting  the  results.  (2)  A  solution  of  a  doubt- 
ful question  in  normal  physiological  chemistry  is  frequently  obtained 
by  establishing  a  pathological  condition,  or  by  taking  advantage  of 
one  occurring  as  a  result  of  disease  or  accident,  and  comparing  the 
composition  of  a  tissue  or  fluid  under  these  conditions  with  those 
from  a  normal  subject.  (3)  Pathological  chemical  composition  and 
processes  are  variations,  either  qualitative  or  quantitative,  from  the 
normal,  and  can  therefore  only  be  studied  by  comparison  with  the 
normal,  hence  the  study  of  " physiological "  and  "pathological" 
chemistry  must  go  hand  in  hand.  (4)  The  substances  most  nearly 
concerned  in  the  functions  of  life  are  of  the  most  complex  chemical 
constitution,  and  their  study  requires  a  high  degree  of  chemical 
knowledge,  patience  and  ingenuity.  The  physiological  chemist  must 
be  a  thoroughly  trained  chemist,  equipped  with  sufficient  medical 
knowledge  for  the  study  of  this  chemical  specialty,  not  a  physiologist 
or  a  pathologist  who  dabbles  in  chemistry. 

Vegetable  physiological  chemistry  is  particularly  of  interest  to  the 
agriculturist,  animal  physiological  chemistry  to  the  veterinarian  and 
the  physician.  Only  the  latter  branch  will  be  here  considered. 

The  subject  maybe  divided  into  two  sections:  (1)  the  study  of 
the  properties,  physical  and  chemical,  of  the  various  substances 
(proximate  principles)  which  occur  in  living  bodies;  (2)  that  of  the 
chemical  changes,  chemical  processes,  which  take  place  in  living 
organisms.  The  first  division  is  a  part  of  pure  chemistry,  and  has 


PHYSIOLOGICAL    CHEMISTRY  511 

been  considered  in  the  preceding  pages,  the  more  important  subjects 
of  the  second  division  will  be  discussed  in  the  following. 

One  of  the  most  striking  differences  between  unorganized  and 
organized  nature  is  that  in  the  former  those  changes  which  occur  are 
almost  entirely  physical,  while  in  the  latter  they  are  essentially  chem- 
ical. Water  passes  through  the  conditions  of  solid,  liquid  and  vapor, 
the  rocks  are  eroded,  the  air  varies  in  temperature  and  moves  from 
place  to  place,  all  physical  changes,  but  neither  water,  rock  nor  air 
suffers  change  of  composition.  But  in  vegetable  and  animal  bodies 
changes  in  composition  are  constant  and  essential  to  life;  the  atoms 
of  carbon,  hydrogen,  nitrogen  and  oxygen  are  in  constant  passage 
from  one  form  of  combination  to  another.  Indeed  life  may  be  said 
to  consist  of  chemical  reactions;  and  the  physical  processes  and  con- 
ditions of  and  in  the  bodies  of  vegetables  or  animals  occur  or  exist 
that  these  reactions  may  take  place. 

Energy,  like  matter,  is  indestructible,  and  cannot  be  created. 
The  sum  of  potential  and  kinetic  energy  in  the  universe  is  immutable. 
The  relative  proportions  of  the  two  forms  of  energy  is  constantly 
varying.  Every  chemical  change  involves  the  conversion  of  poten- 
tial into  kinetic  energy,  or  the  reverse.  The  atoms  of  carbon  and 
oxygen  uncombined  with  each  other,  are  endowed  with  a  definite 
amount  of  potential  energy,  which  is  converted  by  their  union  into 
a  definite  and  equivalent  amount  of  kinetic  energy,  which  is  mani- 
fested and  is  measurable  as  heat,  which  may  in  turn  be  converted 
into  other  forms  of  energy.  Once  united,  the  carbon  and  oxygen 
have  lost  the  potential  energy  which  they  possessed  while  ununited, 
and,  as  energy  cannot  be  created,  they  can  only  recover  it  by  some 
second  reaction  in  which  an  equivalent  quantity  of  kinetic  energy 
becomes  potential  in  separating  the  atoms  once  more.  This  cycle 
may  be  mathematically  expressed  by  the  equations:  C+O2+ potential 
=  CO2-+- kinetic,  and  CO2+kinetic  =  C+O2  +  potential.  As  animal 
bodies  are  constantly  converting  potential  energy  into  the  kinetic 
forms  of  heat,  motion,  etc.,  they  must  be  supplied  with  potential 
energy  from  without,  which,  in  its  turn,  has  been  derived  from  some 
form  of  kinetic  energy. 

The  source  of  this  energy  is  the  kinetic  energy  of  the  sun's  rays. 
The  green  parts  of  plants  owe  their  color  to  the  presence  of  a  pig- 
ment called  chlorophyll,  which  is  only  present  in  leaves  and  stems 
exposed  to  sunlight.  In  the  daytime,  and  while  exposed  to  sunlight, 
plants  absorb  carbon  dioxid  from  the  air  and  give  off  oxygen ;  during 
the  night  they  absorb  oxygen  and  evolve  carbon  dioxid;  but  in  very 
much  less  quantity.  Plants  also  absorb  water  and  ammonia.  From 
these  comparatively  simple  substances  the  plants  form  carbohydrates 


512  MANUAL    OF    CHEMISTRY 

and  proteins  under  the  influence  of  the  kinetic  energy  of  the  sun's 
rays,  which  thereby  becomes  potential.  In  the  animal  body  the  car- 
bohydrates and  proteins  are  converted  into  carbon  dioxid,  water  and 
urea  (the  last-named  yields  ammonia  by  fermentation)  and  their 
potential  energy  becomes  kinetic.  The  tissues  of  the  plant  are, 
directly  or  indirectly,  the  food  of  the  animal,  and  the  excreta  of  the 
animal  constitute  the  food  of  the  plant.  The  chemical  processes  in 
the  vegetable  are  essentially  synthetic,  producing  complex  substances 
from  simpler  forms  of  combination;  but  analytic  processes  also  occur 
in  vegetables,  as  that  which  results  in  the  evolution  of  oxygen,  above 
referred  to.  The  processes  of  animal -nature  are,  on  the  other  hand, 
essentially  analytic,  complex  combinations  being  reduced  to  simpler 
forms;  but  synthetic  processes  also  occur  in  animal  bodies,  as  in  the 
formation  of  hippuric  and  the  ester -sulf uric  acids. 

The  composition  of  various  articles  used  as  foods,  the  effects 
upon  them  of  different  methods  of  preparation,  and  the  relative 
proportions  in  which  the  several  components  should  be  contained 
in  properly  adjusted  dietaries,  are,  like  the  composition  of  air  under 
varying  conditions,  important  subjects  of  inquiry  for  the  hygienic 
chemist.  In  this  place,  however,  we  will  content  ourselves  with  the 
statement  that  the  materials  required  for  the  chemical  processes 
taking  place  in  the  body,  and  contributing  to  the  growth  or  repair 
of  the  tissues,  and  to  the  production  of  kinetic  energy,  are  of  six 
classes:  (1)  Oxygen,  (2)  water,  (3)  mineral  salts,  (4)  carbohydrates, 
(5)  fats,  (6)  proteins.  Of  these,  oxygen,  water  and  salts  pass 
into  the  system  by  the  physical  processes  of  diffusion  and  absorption, 
without  the  necessity  of  any  preliminary  chemical  treatment.  But 
the  fats,  the  carbohydrates,  and,  notably,  the  proteins,  require  more 
or  less  extensive  chemical  modification  from  the  forms  in  which  they 
are  taken  into  the  mouth  before  they  can  be  absorbed.  This  is  the 
purpose  of  digestion. 

Chemical  processes  occurring  in  the  body  may  therefore  be  divided 
into  the  two  classes  of  preparatory  and  essential.  The  former  in- 
cluding the  processes  preparatory  to  absorption  which  occur  in  the 
alimentary  canal;  the  latter  the  metabolism  of  the  tissues,  cells,  and 
fluids  of  the  body. 

DIGESTION. 

SALIVA. 

The  saliva  is  a  mixture  of  the  secretions  of  several  glands:  The 
submaxillary  saliva,  which  may  be  obtained  by  inserting  a  canula  in 
Wharton's  duct,  is  a  clear,  thin,  colorless,  slightly  viscid,  frothy, 


SALIVA  513 

alkaline  liquid;  sp.  gr.  1002  to  1003;  containing  3.6  to  4.5  p/m  of 
solids.  These  solids  consist  of  mucin,  a  trace  of  albumin,  a  diastatic 
erizyrn,  KCl,NaCl,NaaHPO4,Mg^2(PO4)2,NaHCO8fOaH3(CO8)«1  and 
KCNS.  In  the  dog,  the  saliva  obtained  by  nerve -excitation  differs 
according  to  the  nerve  supply  which  is  irritated:  the  chorda  tympani, 
or  cerebral  saliva  contains  12  to  14  p/m  of  solids;  sp.  gr.  1004  to 
1005.6;  is  more  abundant  and  contains  less  mucin  than  the  sympa- 
thetic saliva,  which  contains  16  to  28  p/m  of  solids;  sp.  gr.  1007.5  to 
1018. 

The  sublingual  saliva  is  clear,  viscid,  alkaline,  and  contains 
mucin,  a  diastatic  enzym  and  potassium  thiocyanate. 

The  parotid  saliva,  which  may  be  obtained  by  a  canula  inserted 
into  Steno's  duct,  is  a  thin  liquid,  usually  alkaline,  but  sometimes 
neutral,  or  even  faintly  acid;  sp.  gr.  1003  to  1012.  It  contains  5  to 
16  p/m  of  solids,  among  which  are  a  small  quantity  of  albumin  and 
a  diastatic  enzym,  but  no  mucin.  Potassium  thiocyanate  is  some- 
times present. 

Mixed  saliva  consists  of  the  above,  plus  the  secretions  of  the 
mucous  glands.  It  is  colorless,  tasteless,  odorless,  opalescent,  frothy, 
slightly  viscid;  and  cloudy  from  the  presence  of  epithelium,  mucus 
corpuscles,  leptothrix,  and  food  particles.  On  exposure  to  air  it  be- 
comes more  cloudy  and  covered  by  a  pellicle,  which  consists  of  calcium 
carbonate.  Its  reaction  is  alkaline,  the  average  alkalinity  being  equal 
to  0.8  p/m  of  Na2COs,  and  diminishing,  sometimes  to  acidity,  after 
meals.  Sp.  gr.  1002  to  1008.  It  contains  5  to  10  p/m  of  solids,  of 
which  the  organic  constituents  are  albumin,  mucin,  urea,  thiocyanate, 
and  two  enzymes,  ptyalin  and  glucase.  According  to  an  analysis  of 
Hammerbacher,  it  has  the  composition  :  Water:  994.2;  mucus  and 
epithelium:  2.2;  soluble  organic  constituents:  1.4;  thiocyanate:  0.04; 
salts:  2.2.  The  composition  of  the  ash  in  1,000  parts  is:  K2O-457.2; 
Na20-95.9  ;  CaO  and  traces  of  Fe203-50.11  ;  MgO-1.55  ;  SO3-63.8  ; 
P2O5-188.48  ;  Cl-183.52. 

Enzymes  are  a  class  of  physiologically  important  substances, 
some  of  vegetable  origin,  like  diastase,  emulsin,  papain  and  myrosin, 
others  of  animal  origin,  like  ptyalin,  pepsin  and  trypsin,  concerning 
whose  chemistry  but  little  is  known  beyond  the  effects  which  they 
produce.  They  are  sometimes  referred  to  as  soluble  or  unorganized 
ferments  in  comparison  with,  yet  in  distinction  from  the  true  fer- 
ments, such  as  the  yeast  plant,  mother-of- vinegar,  etc.,  which  are 
vegetable  organisms,  while  the  enzymes  are,  apparently,  chemical 
compounds.  They  are  protein  in  character,  precipitated  by  alcohol 
and  by  lead  acetate,  not  diffusible,  and  are  destroyed  by  the  tempera- 
ture of  boiling  water.  Their  prominent  characteristic  is  their  power, 
when  present  even  in  small  quantity,  of  setting  up  a  chemical  change 
33 


514  MANUAL   OP    CHEMISTRY 

in  certain  other  substances.  Some,  called  amylolytic  or  diastatic 
enzymes,  convert  starch  into  maltose  or  into  glucose;  some,  referred 
to  as  proteolytic  enzymes,  convert  albumins  and  globulins  into 
albumoses  and  peptones;  others  cause  the  saponification  of  fats; 
others  invert  cane  sugar  or  maltose;  while  still  others  set  up  a 
variety  of  other  actions  (emulsin,  inyrosin,  chymosin,  etc.).  Their 
activity  is  only  manifested  within  narrow  ranges  of  temperature,  the 
body  temperature  being  the  most  favorable  for  the  action  of  the 
digestive  enzymes.  Their  activity  also  diminishes  with  the  accumula- 
tion of  their  products,  and  is  finally  arrested  thereby.  It  is  also 
impeded  by  putrefaction.  The  presence  of  1  in  200  of  chloroform, 
which  completely  arrests  fermentations,  favors  the  action  of  enzymes 
by  preventing  putrefaction,  and  chloroform -water  is  frequently  used 
to  prevent  putrefaction  in  experimentation  extending  over  consider- 
able time.  Some  cells  produce  zymogens,  i.e.  substances  which  are 
not  enzymes,  but  which,  under  certain  influences,  as  by  combina- 
tion with  acid,  generate  enzymes.  Most  enzymes  are  soluble  in 
glycerol. 

Saliva  enzymes.  —  The  saliva  contains  two  enzymes:  one  amylo- 
lytic, converting  hydrated  starch  into  maltose  and  iso- maltose  (p. 
273),  which  exists  in  human  saliva  at  all  ages,  but  not  in  the  saliva 
of  the  carnivora,  known  as  ptyalin.  The  other  glucase,  present  in  the 
saliva  in  small  amount  only,  which  converts  maltose  into  glucose. 
Ptyalin  has  not  been  obtained  in  a  condition  of  purity.  Gautier's 
method  gives  the  product  most  nearly  approaching  purity:  the  saliva 
is  treated  with  a  large  quantity  of  strong  alcohol;  the  precipitate  is 
collected  and  redissolved  in  water;  albumens  are  precipitated  by 
mercuric  chlorid  and  separated  by  filtration;  the  excess  of  mercury 
is  removed  by  hydrogen  sulfid;  the  salts  are  removed  by  dialysis; 
and  the  ptyalin  again  precipitated  by  alcohol. 

The  activity  of  the  amylolytic  action  of  saliva  is  directly  pro- 
portionate to  the  quantity  of  the  enzymes  present.  The  most  favor- 
able reaction  is  a  very  faintly  acid  one,  due  to  carbonic  acid,  and 
the  activity  is  diminished  by  either  an  alkaline  reaction  or  an  acid 
one  due  to  mineral  acids.  The  action  is  completely  arrested  by  the 
presence  of  0.03  p/m  of  HC1.  The  most  favorable  temperature  is 
40°  (104°  F.).  The  accumulation  of  its  products  interferes  with  the 
continuance  of  the  action,  and  it  is  therefore  more  rapid  and  exten- 
sive when  it  takes  place  in  a  dialyser  than  when  it  occurs  in  a  glass 
vessel.  On  the  other  hand,  it  is  favored  by  the  presence  of  peptones. 
The  presence  of  0.05  p/m  of  HgCl2  arrests  the  action,  and  a  like 
result  is  produced  by  5  p/m  of  MgS(>4,  while  0.25  p/m  of  the  latter 
salt  favors  the  action. 

The  total  quantity  of  saliva  secreted  in  24  hours  has  not  been 


GASTRIC   JUICE  AND   GASTRIC   DIGESTION  515 

directly  determined  in  the  human  subject.  It  is  estimated  at  from 
600  to  1,500  cc.  During  mastication  1  gram  of  salivary  gland  pro- 
duces 13  grams  of  saliva  per  hour.  The  quantity  is  increased  by 
pilocarpin  and  by  eserin,  and  diminished  by  atropin.  Many  metallic 
salts  are  eliminated  by  the  saliva,  e.  g.,  those  of  mercury  and  po- 
tassium, and  the  bromids  and  iodids;  others  do  not  appear  in  the 
saliva,  e.  g.,  the  salts  of  iron.  The  quantity  is  pathologically  in- 
creased in  poisoning  by  the  soluble  mercurials,  the  mineral  acids  and 
alkalies;  in  neurotic  conditions,  and  in  inflammatory  diseases  of  the 
mouth.  It  is  diminished  in  febrile  diseases,  in  diabetes,  sometimes 
in  nephritis,  and  under  violent  psychic  emotions. 

Salivary  calculi  are  rarely  met  with,  varying  in  size  from  mere 
granules  to  masses  weighing  18.6  grams.  They  consist  principally 
of  calcium  carbonate,  with  some  tricalcic  phosphate,  and  from  50  to 
368  p/m  of  organic  matter. 

GASTRIC   JUICE   AND   GASTRIC   DIGESTION. 

While  at  rest,  in  the  intervals  between  digestion,  the  stomach 
contains  only  a  thick,  slimy,  neutral,  or  even  alkaline  liquid,  the 
gastric  mucus,  or  succus  pyloricus,  so-called  because  it  is  the 
product  of  glands  located  principally  at  the  pyloric  end.  The  true 
gastric  juice  is  produced  only  during  digestion,  or  by  stimulation  of 
the  secreting  glands,  the  fundus,  or  pepsin  glands,  by  "chemical"  or 
"psychic"  action.  The  gastric  juice  of  man  has  not  been  obtained 
free  from  saliva.  Mixed  with  saliva,  it  has  been  obtained  in  cases  of 
traumatic  (Beaumont),  or  surgical  (Richet)  gastrostomy.  From 
animals  it  may  be  obtained  pure  by  the  establishment  of  gastric  and 
oesophageal  fistulae. 

The  gastric  juice  is  a  slightly  cloudy,  almost  colorless  liquid,  sp. 
gr.  1001  to  1010,  having  an  acid  taste  and  a  strongly  acid  reaction. 
It  deposits  a  sediment,  which,  unmixed  with  food  particles,  contains 
gland  cells  and  nuclei,  mucus  corpuscles  and  altered  cylindrical 
epithelium. 

According  to  an  analysis  by  Schmidt  of  human  gastric  juice, 
mixed  with  some  saliva,  it  contains:  Water -99. 44,  solids  -0.56,  free 
hydrochloric  acid,  0.25.  The  solids  consist  of  :  organic  substances 
(pepsin,  etc.)  -0.32,  NaCl-0.14,  KC1-0.05,  Ca012 -0.006,  phosphates 
of  Ca,  Mg,  and  Fe  -0.015.  Among  the  organic  constituents  are  a 
small  quantity  of  a  nucleoproteid,  a  mucin,  an  albumose  (?), 
and  two  zymogens  which  produce  the  two  enzymes,  pepsin  and 
rennet.  The  most  important  constituents  are  the  free  acid  and  the 
zymogens. 

It  is  now  established  that  the  free  acid  of  the  normal,  unmixed 


516  MANUAL    OP    CHEMISTRY 

gastric  juice  is  hydrochloric  acid.  During  digestion  lactic  acid  or 
butyric  or  acetic  acid  may  be  present.  They  are,  however,  not 
products  of  secretion,  -but  are  derived  from  constituents  of  the  food. 
The  amount  of  hydrochloric  acid  present  varies  in  different  animals, 
and,  within  narrower  limits  in  the  same  animal  at  different  times. 
The  gastric  juice  of  the  dog  contains  from  2  to  6  p/rn,  that  of  the  cat 
about  5  p/m.  The  proportion  usually  accepted  as  present  in  human 
gastric  juice  is  2  to  3  p/m;  but  it  is  probable  that  this  estimate  is 
too  low. 

The  exact  mechanism  of  the  formation  of  the  gastric  hydrochloric 
acid  is  unknown.  That  it  is  derived  from  the  chlorids  of  the  blood 
is  most  probable,  although  it  may  result  from  decomposition  of  chlo- 
rinated amids,  which  have  been  found  to  exist  in  gland  tissues.  A 
fact  which  supports  the  supposition  of  the  derivation  from  the 
chlorids  is  that  if  dogs  be  given  a  diet  from  which  chlorids  are 
excluded  the  hydrochloric  acid,  after  a  time,  ceases  to  be  formed, 
while  pepsin  continues  to  be  secreted;  and  if  now  the  animal  be 
given  bromids,  iodids,  or  chlorids,  the  gastric  juice  will  contain 
hydrobromic,  hydriodic,  or  hydrochloric  acid,  as  the  case  may  be. 
The  most  probable  supposition  with  regard  to  the  method  of  forma- 
tion of  the  acid  from  the  chlorids  is  that  it  is  produced  by  chemical 
action,  the  chlorids  being  decomposed  by  the  free  carbon  dioxid  (or 
carbonic  acid)  in  the  blood,  according  to  the  equation:  2NaCl+CO2- 
-hH2O=Na2CO3-f-2HCl;  or  it  may  be  the  result  of  decomposition  of 
calcium  chlorid  by  the  disodic  phosphate  of  the  blood:  2Na2HP(>4- 
+3CaCl2=Ca3(PO4)2+2H01+4NaCl.  The  former  reaction  is  the 
more  probable,  because  of  the  generation  of  alkali,  mentioned  below, 
during  stomach  digestion.  It  has  been  suggested  also  that  the 
chlorids  may  be  decomposed  by  an  electrolytic  action  resulting  in 
reactions  such  as:  2NaCl— Na2+Cl2;  Na2+H2O-f  C02=Na2C03+H2, 
and  H2+Cl2=2HCl.  There  is,  however,  no  proof  of  the  occurrence 
of  such  action.  The  reaction  2NaCl+CO2+H2O=Na2CO8+2HCl 
implies  the  formation  of  a  quantity  of  alkali  equivalent  to  the  amount 
of  acid  generated,  which  should  manifest  itself  somewhere  in  the 
system  to  a  degree  proportionate  to  the  quantity  of  acid  formed  at 
different  times.  It  is  supposed  that  the  alkali  thus  produced  enters 
into  combination  with  the  lecithalbumens  which  exist  in  gland  cells. 
Whether  this  is  the  case  or  not,  it  is  known  that  the  acidity  of  the 
urine  varies  inversely  with  the  activity  of  hydrochloric  acid  forma- 
tion; and  that  the  urine  may  even  become  alkaline  during  the  greatest 
activity  of  stomach  digestion  and  in  hyperchlorhydria. 

Pepsin  and  Pepsinogen. — Pepsin  exists  in  the  gastric  juice  of 
all  vertebrates,  and  at  all  ages.  It  has  not  been  obtained  in  a  con- 
dition of  purity,  the  nearest  approach  thereto  being  the  product  of 


GASTRIC   JUICE   AND   GASTRIC   DIGESTION  517 

Briicke's  method  :  The  mucous  membrane  is  extracted  with  water 
containing  phosphoric  acid;  the  filtered  extract  is  treated  with  lime 
water;  the  precipitate  of  tricalcic  phosphate  containing  the  pepsin, 
which  it  carries  down  mechanically,  is  dissolved  in  dilute  hydrochloric 
acid,  and  the  solution  freed  from  salts  by  dialysis.  For  digestion 
experiments  an  extract  made  by  macerating  the  mucous  membrane  in 
glycerol  containing  1  p/m  of  HC1  and  filtered  after  8-14  days,  may  be 
used.  As  prepared  by  Briicke's  method  pepsin  is  soluble  in  water 
and  in  glycerol,  from  which  it  may  be  precipitated  by  alcohol.  It 
does  not  give  the  albumen  reactions.  In  aqueous  solution  its  activity 
is  rapidly  destroyed  by  boiling,  more  slowly  in  neutral  solution  at 
55°,  in  acid  solution  at  65°,  at  70°  in  presence  of  peptones,  and 
quite  rapidly  even  at  38-40°  in  presence  of  very  small  quantities  of 
alkaline  carbonates.  When  dry  it  may  be  heated  to  100°  without 
decomposition.  The  characteristic  property  of  pepsin  is  that  it  dis- 
solves albumens,  with  formation  of  albumoses  and  peptone,  in  acid, 
but  not  in  neutral  or  alkaline  solutions. 

Pepsinogen,  or  propepsin,  is  the  zymogen  from  which  pepsin  is 
formed  by  contact  with  hydrochloric  acid,  and  is  probably  produced 
by  the  chief  cells  of  the  fundus  glands.  The  mucous  membrane  of 
the  fasting  stomach  yields  to  dilute  hydrochloric  acid  an  actively 
digesting  extract,  even  after  treatment  with  1%  sodium  carbonate 
solution,  at  40°,  which  very  rapidly  destroys  the  activity  of  pepsin, 
but  acts  only  very  slowly  upon  pepsinogen.  It  has  been  supposed 
that  pepsinogen  and  hydrochloric  acid  combine  chemically  together 
to  form  a  definite  compound,  the  active  material  of  the  gastric  juice, 
which  has  been  called  pepsohydrochloric  acid. 

As  has  been  stated  above,  the  characteristic  reaction  of  pepsin  is 
its  power  of  dissolving  albumens  in  acid  solution.  If  a  fragment  of 
coagulated  white  of  egg  be  immersed  in  HC1  of  2-4  p/m  at  40°  it  is 
not  affected,  but  if  a  trace  of  pepsin  be  also  present,  the  edges  of  the 
fragment  are  soon  rounded,  and  the  material  becomes  transparent, 
and  finally  dissolves.  A  similar  effect  is  produced  more  rapidly  and 
at  a  lower  temperature  (20°)  with  fibrin.  A  similar  action,  but 
slower,  occurs  with  acids  other  than  hj^drochloric,  diluted  strong  acids 
acting  better  than  weak  acids.  The  rapidity  of  the  action  is  also 
affected  by  other  conditions :  it  is  more  rapid  if  the  products  of  the 
action  be  removed  by  dialysis  than  if  they  be  allowed  to  accumulate; 
and  it  is  less  rapid  in  presence  of  salicylic  acid,  metallic  salts,  alka- 
loids, phenol,  sulfates,  or  of  alcohol  in  greater  proportion  than  10%. 
The  most  favorable  temperature  is  40°,  and  the  most  advantageous 
proportion  of  HC1  about  2.5  p/m. 

The  conversion  of  albumen  into  peptone  is  by  no  means  a  simple 
process.  The  first  stage  consists  in  the  conversion  of  albumen  into 


518  MANUAL    OF    CHEMISTRY 

acid -albumen  (syntonin,  p.  504).  This  then  undergoes  gradual 
cleavage  by  hydrolysis,  with  diminution  of  molecular  weight,  and 
increase  in  the  degree  of  diffusibility,  until  the  end  product  is 
reached.  Intermediate  between  the  acid- albumens  and  the  peptones, 
a  series  of  substances,  called  albumoses,  or  propeptones  are  formed, 
which  differ  from  the  albumens  in  their  behavior  towards  nitric  acid 
and  towards  ferrocyanid.  With  nitric  acid  at  the  ordinary  tempera- 
ture, or  with  acetic  acid  and  potassium  ferrocyanid,  they  form  pre- 
cipitates which  redissolve  on  the  application  of  heat,  and  are  repre- 
cipitated  on  cooling.  From  the  peptones  they  differ  chiefly  in  being 
precipitated  from  their  solutions  by  salting  with  ammonium  sulfate, 
although  those  albumoses  most  nearly  related  to  the  peptones,  the 
deutero- albumoses,  are  only  partially  precipitated  in  that  manner. 
The  albumoses  are  divided  into  two  groups:  the  primary  albumoses, 
including  the  proto-  and  hetero-albumoses  (below),  and  the  secon- 
dary, or  deutero-albumoses ;  the  former  being  more  nearly  related 
to  the  native  albumens,  the  latter  more  nearly  to  the  peptones.  They 
differ  from  each  other  principally  in  their  behavior  towards  nitric 
acid  :  the  primary  albumoses  are  precipitated  by  nitric  acid,  even 
in  the  absence  of  neutral  salts,  while  the  secondary  albumoses 
are  not  precipitated  under  these  circumstances,  although  they  are 
precipitated  by  nitric  acid  in  presence  of  neutral  salts.  They  also 
behave  differently  towards  ammonium  sulfate,  which  precipitates  the 
primary  albumoses  completely,  the  secondary  albumoses  only  par- 
tially. The  primary  albumoses  are  also  precipitated  by  cupric 
sulfate  (1:200)  which  does  not  precipitate  the  secondary  albumoses. 
In  the  process  of  cleavage  of  the  native  albumens  by  the  action  of 
proteolytic  enzymes,  or  of  dilute  mineral  acids  alone,  the  first  prod- 
ucts form  two  groups,  differing  from  each  other  in  the  facility  with 
which  they  are  further  acted  upon  by  the  acids  and  enzymes:  (1)  the 
hemi  -  group,  from  which  the  proto -albumoses  are  derived,  being 
readily  soluble  in  dilute  acids,  or  by  the  action  of  enzymes  and  acids; 
and  (2)  the  anti-group,  from  which  the  hetero-albumoses  and  anti- 
albumose,  the  latter  insoluble  in  acids,  are  derived;  which  are  in- 
soluble in  acids  except  in  presence  of  enzymes,  and  then  more 
slowly  than  the  hemi -compounds.  The  albumoses  obtained  from 
the  several  native  albumens  are  not  identical.  From  each  parent 
substance  different  proteoses  are  formed,  which  are  distinguished 
as  albumoses,  globuloses,  vitelloses,  caseoses,  etc.  The  final 
products  of  the  action  are  the  peptones.  These  are  extremely  solu- 
ble in  water,  hygroscopic,  highly  diffusible,  are  not  precipitated  by 
ammonium  sulfate,  nor  by  nitric  acid,  even  in  solutions  saturated 
with  salts,  nor  by  the  usual  precipitants  of  the  albumens,  except 
phosphotungstic  and  phosphomolybdic  acids,  mercuric  chlorid,  strong 


GASTRIC   JUICE   AND  GASTRIC   DIGESTION  519 

alcohol,  and   tannin.     They  are  not  coagulated  by  heat.     They  give 
the  biuret  reaction  (p.  525). 

The  changes  above  described  may  be  thus  expressed   in  tabular 
form 

NATIVE  ALBUMEN 
I 

GROUP  I Acid -albumen GROUP  II 

Heml-  Anti- 

Sol.  in  3%  H2SO4;  readily  Insol.  in   dil.  acids.     Difficultly 

sol.  in  acids  and  enzymes.  acted  on  by  acids  and  enzymes. 


Proto-albumoses  Hetero-albumoses  Anti-albumid 

Sol.  in  H2O,  and  in  dil.  Insol.  in  H2O,  sol.  in  Insol.  in  dil.  acids. 

salt  soln.  dil.  salt  soln. 

I  I 

Proto-albumoses  and  hetero-albumoses  are  Primary  albumoses 
Pptd.  by  HNO3  in  absence  of  salts;  pptd.  by  CuSO4 
(1:200) ;  completely  pptd.  by  (NH4)2SO4. 


Secondary  albumoses  =  Deutero- albumoses 
Not  pptd.  by  HNO3  in  absence  of  salts;  not  pptd.  by 
CuSO4;  incompletely  pptd.  by  (NH4)2SO4. 

Peptones  ^ 

Not  pptd.  by  HNO3  even  in  presence  of  salts; 
not  pptd.  by  (NH4)2SO4. 

The  peptone  which  is  the  final  product  of  peptic  digestion  is" 
called  ampho-peptone,  and  is  further  decomposable  by  tryptic  diges- 
tion (p.  533)  into  anti-peptone  and  hemi-peptone,  which  differ  from 
each  other  in  that  by  continued  tryptic  digestion,  the  latter  is  further 
decomposed  with  formation  of  ainido- acids,  leucin,  tyrosin,  etc.,  while 
the  anti- peptone  remains  undecomposed. 

While  the  peptones  are  the  end-products  of  the  action  of  digestive 
enzymes  upon  the  proteins,  they  do  not  exist  in  the  normal  blood, 
not  even  in  that  of  the  portal  vein  during  active  digestion  of  pro- 
teins, nor  is  the  protein -content  of  the  chyle  appreciably  increased 
during  their  absorption.  It  is  supposed  that  the  peptones,  and 
albumoses,  are  converted  into  serum -albumin,  or  other  form  of  pro- 
tein combination  in  the  gastro- intestinal  mucous  membrane,  by  some 
process  in  which  the  leucocytes  play  a  part. 

Pepsohydrochloric  acid  exerts  the  following  actions  upon  other 
substances:  the  nucleoalbumens  and  nucleoproteids  are  decomposed, 
leaving  residues  of  pseudonuclein  or  of  nuclein,  which  are  unacted 
upon  (p.  506),  while  the  albumens  are  dissolved  as  peptones.  Glyco- 
proteids  are  similarly  decomposed,  with  formation  of  peptones  and 
reducing  substances.  Collagen  is  slowly  digested,  by  conversion, 
first  into  gelatin,  then  into  proto-  and  deutero-gelatoses,  and  finally 
into  peptone.  Keratin  is  not  acted  upon;  elastin  only  very  slowly. 
Animal  and  vegetable  cell  membranes,  being  made  up  of  keratin  and 


520  MANUAL    OF    CHEMISTRY 

elastin  in  varying  proportion,  are  differently  acted  upon  according  to 
their  tenure  of  their  two  constituents.  The  connective  tissue  of  the 
panniculus  is  dissolved.  Haemoglobin  is  decomposed  with  formation 
of  haematin  and  acid -albumen.  Fats  and  carbohydrates  are  unacted 
upon,  except  that  saccharose  may  be  inverted. 

Chymosin  and  Chymosinogen — are  the  milk -curdling  enzym  and 
the  zymogen  from  which  it  is  derived.  The  enzym  exists  in  normal 
human  gastric  juice,  and  is  the  active  constituent  of  rennet,  the  salted 
and  dried  fourth  stomach  of  the  calf,  used  by  cheese -makers.  Its 
function  is  rapidly  destroyed  by  a  temperature  of  60°,  and  slowly 
(in  48  hours)  at  40°.  Its  characteristic  property  is  that  of  coag- 
ulating milk,  or  a  solution  of  casein  containing  calcium  salts  in 
neutral  or  faintly  alkaline  solution. 

The  observed  abnormal  variations  in  composition  of  the  gastric 
juice  relate  principally  to  the  free  acid.  Free  hydrochloric  acid  may 
be  absent  (anachlorhydria)  in  neurasthenic  conditions,  in  chronic  gas- 
tritis, in  carcinoma  of  the  stomach,  and  in  the  secondary  stage  of 
corrosion  by  mineral  acids  or  alkalies.  It  may  be  present  in  sub- 
normal quantity  (hypochlorhydria)  in  subacute  or  chronic  gastritis, 
ulcer  of  the  stomach,  dilatation,  and  the  earlier  stages  of  carcinoma. 
Or  the  amount  may  be  greater  than  the  normal  (hyperchlorhydria) 
in  neurasthenic  patients,  or,  sometimes,  in  carcinoma.  When  the 
amount  of  free  hydrochloric  acid  is  subnormal,  fermentative  changes, 
usually  prevented  by  the  antifermentative  and  antiseptic  action  of  the 
pepsohydrochloric  acid,  are  set  up,  with  the  formation  of  lactic  and 
even  of  acetic  and  butyric  acids,  with  liberation  of  hydrogen  and 
consequent  eructations  of  gas  and  heartburn.  These  organic  acids 
may  also  frequently  be  present  in  the  stomach,  having  been  introduced 
with  the  food;  lactic  acid  exists  in  sour-krout,  in  pickles,  and  in  all 
kinds  of  bread;  acetic  acid  is  the  acid  of  vinegar;  and  free  butyric 
acid  may  be  present  in  butter.  It  appears  to  have  been  demonstrated 
that  in  most  cases  of  carcinoma  of  the  stomach  lactic  acid  is  present 
in  the  stomach  contents  in  greater  amount  than  can  be  accounted 
for  by  the  test -meals  which  have  been  used.  Pepsin  is  very  rarely 
absent,  only  after  complete  destruction  of  the  pepsin  glands  by  the 
action  of  corrosives.  Chymosin  is  absent  in  carcinoma,  chronic  gas- 
tric oatarrh  and  atrophy  of  the  mucous  membrane.  Abnormal  con- 
stituents, not  introduced  by  the  mouth,  may  also  be  present:  urea 
and  ammonium  carbonate  in  uraemia,  acetone  in  acetonurea,  the 
constituents  of  the  blood,  or  haematin,  as  the  result  of  hemorrhage 
into  the  stomach,  and,  frequently,  the  constituents  of  the  bile, 
by  regurgitation;  also  arsenic  and  morphin  when  they  have  been 
taken  in  poisonous  dose  by  channels  of  absorption  other  than  the 
mouth. 


GASTRIC   JUICE   AND  GASTRIC   DIGESTION  521 

Examination  of  Stomach  Contents. — Usually  it  is  desirable  to 
obtain  the  gastric  secretion  as  free  as  possible  from  the  constituents 
of  food  articles.  With  this  object  the  stomach  contents  are  collected 
after  the  stomach  has  been  washed  out,  and  the  secretion  of  gastric 
juice  stimulated  by  a  "test-meal."  Many  such  have  been  recom- 
mended, of  which  probably  the  most  serviceable  is  that  of  Boas,  con- 
sisting of  a  tablespoonful  of  rolled  oats  and  a  quart  of  water,  boiled 
down  to  a  pint,  to  which  a  little  salt  may  be  added.  The  stomach 
contents  are  collected  one  hour  after  the  meal  has  been  taken. 

Total  Acidity. — Four  factors  may  contribute  to  the  acid  reaction 
of  the  gastric  contents:  free  hydrochloric  acid,  hydrochloric  acid  in 
protein  combination  (see  below),  organic  acids,  and  acid  salts.  The 
sum  of  these,  or  of  such  of  them  as  may  be  present,  constitute  the 
total  acidity.  This  is  determined  by  titrating  10  cc.  of  the  filtered 
gastric  contents  with  N/10  (one -tenth  normal)  caustic  soda  solution, 
using  phenol  phthalem  as  an  indicator.  As  each  cc.  of  the  N/10 
alkali  corresponds  to  0.00365  gm.  of  HC1,  the  number  of  cc.  of  alkali 
used,  multiplied  by  0.0365  (if  10  cc.  of  gastric  contents  have  been 
used)  gives  the  percentage  of  total  acidity,  expressed  in  terms  of 
hydrochloric  acid.  Another  form  of  expression  is  sometimes  used, 
i.  e.,  the  number  of  cc.  of  N/10  caustic  soda  solution  required  to 
neutralize  100  cc.  of  the  material.  This  is  obtained,  if  10  cc.  of  ma- 
terial are  used,  by  multiplying  the  number  of  cc.  of  N/10  alkali 
required  to  neutralize,  by  10.  The  normal  total  acidity  after  a  Boas 
meal  is  0.15  to  0.30%  HC1,  which  is  equivalent  to  40  to  80  cc. 
N/10  NaHO. 

Presence  of  Free  Acids. — The  next  step  is  to  determine  whether 
any  of  the  total  acidity  is  due  to  free  acids,  and  if  it  is  to  what  acid 
or  acids.  This  is  accomplished  by  the  use  of  indicators,  sub- 
stances giving  different  colors  with  certain  classes  of  acid  or  alkaline 
substances.  The  red  color  of  alkaline  phenolphthalem,  used  as  an 
indicator  above,  is  discharged  by  all  four  factors  contributing  to  the 
acidity  of  the  gastric  contents,  therefore  it  is  used  in  determining  the 
total  acidity.  Congo  red  forms  an  orange -yellow  solution  in  alcohol, 
which,  when  largely  diluted,  is  turned  blue  by  a  drop  or  two  of  a 
.001%  solution  of  HC1,  or  by  other  free  acids,  mineral  or  organic,  but 
not  by  acid  salts.  If,  therefore  a  few  drops  of  the  gastric  contents 
give  a  blue  color  with  a  drop  or  two  of  dilute  congo-red  solution,  a 
free  acid  is  present. 

To  detect  free  hydrochloric  acid  an  indicator  must  be  used  which 
will  react  with  mineral  acids,  but  not  with  organic  acids  or  with  acid 
salts.  Several  have  been  suggested,  of  which  the  following  are 
desirable  :  (1)  The  phloroglucin- vanillin  reaction — Phloroglucin  and 
vanillin  are  dissolved  in  alcohol  in  the  proportion  of  2  gm.  of  the 


522  MANUAL    OF    CHEMISTRY 

former  and  1  gm.  of  the  latter  in  30  ec.  of  the  solvent  (Gunzburg's 
reagent) .  A  few  drops  of  the  filtered  gastric  contents  and  the  same 
quantity  of  the  freshly -prepared  reagent  are  mixed  in  a  porcelain 
dish,  and  evaporated  on  the  water  bath:  in  the  presence  of  free  min- 
eral acids  a  brilliant  scarlet  color  is  produced,  beginning  at  the  upper 
border.  Delicacy=.05  p/m.  HC1.  Not  interfered  with  by  albumoses 
or  peptones.  (2)  Resorcin- sugar — The  reagent  is  made  by  dissolving 
5  gm.  of  resorcinol  and  3  gm.  of  sugar  in  100  cc.  of  dilute  alcohol, 
and  is  used  in  the  same  manner  as  the  phloroglucin- vanillin  reagent, 
giving  a  rose -red  color  with  free  mineral  acids.  Delicacy=.05  p/m 
HC1.  (3)  Dimethyl -amido-azobenzene —  forms  a  yellow  alcoholic 
solution,  which  turns  red  with  free  mineral  acids.  Delicacy=.02 
p/m  HC1.  This  and  other  similar  tests  are  applied  by  simply  mixing 
a  few  drops  of  the  indicator  with  a  like  quantity  of  the  contents. 
Papers  colored  with  the  several  indicators  are  sometimes  used,  but 
they  are  not  as  delicate  as  the  solutions. 

Negative  results  of  these  tests  with  a  sample  of  gastric  contents 
of  unknown  origin  do  not  prove  that  the  stomach  is  not  secreting  the 
normal  quantity  of  hydrochloric  acid  (see  Quantitative,  below). 
Such  samples  are  met  with  to  which  double  the  amount  of  HC1 
normally  present  may  be  added,  and  not  reveal  its  presence  upon 
application  of  the  tests. 

Quantitative  Determination  of  HC1. — Chlorin  may  exist  in  the 
gastric  contents  during  digestion  of  usual  food  articles  in  three  forms 
of  combination:  as  free  hydrochloric  acid,  as  "loosely  combined" 
acid,  and  as  chlorids,  all  of  which  must  be  taken  into  consideration, 
along  with  the  acid  salts  and  organic  acids,  in  determining  the 
amount  of  HC1  produced  by  the  stomach.  By  "loosely  combined 
HC1 "  is  meant  that  portion  of  the  free  HC1  secreted  by  the  stomach 
which  has  entered  into  combination  with  the  proteins  to  form  acid- 
albumens;  and  the  "effective  HC1"  is,  clearly,  the  sum  of  the  free 
and  the  loosely  combined.  The  quantity  of  acid  that  can  be  thus 
combined  is  considerable.  Thus  100  gm.  of  each  of  the  following 
food  articles  can  take  up  the  amounts  of  HC1  stated,  in  grams  : 
Cheese -1.3  to  2.6,  meat -1.6  to  2.2,  milk -0.42,  bread -0.3  to  0.7, 
beer  -0.15. 

Of  the  several  methods  which  have  been  devised,  probably  the 
most  desirable  are  those  of  Topfer  and  of  Martins  and  Liittke,  some- 
what modified,  the  former,  based  upon  the  use  of  indicators,  being 
the  more  rapid  of  the  two,  the  latter,  based  upon  chlorin  determina- 
tions in  part,  the  more  accurate. 

Topfer' s  Method. — Three  samples  of  10  cc.  each  are  separately 
titrated  with  N/10  NaHO  solution;  in  (1)  using  phenolphthalem  as 
an  indicator,  and  carrying  the  addition  of  alkali  to  a  distinct  red,  not 


GASTRIC   JUICE   AND   GASTRIC    DIGESTION  523 

to  faint  pink  as  is  usual.  This  gives  the  total  acidity  (A),  made  up 
of  free  HOI  (L),  protein  HC1  (C),  and  organic  acids  and  salts  (O). 
In  (2)  alizarin  is  used  as  an  indicator,  to  pure  violet.  This  gives  the 
acidity  due  to  (L+O),  and,  therefore  the  result  of  (2),  subtracted 
from  that  of  (1),  leaves  the  value  of  (C)=protein  HCl.  In  the  third 
sample  (3)  dimethyl -amido-azobenzene  is  used  as  an  indicator,  to 
red.  This  gives  the  value  of  (L)  alone,  i.  e.,  free  hydrochloric  acid. 
If  the  value  of  (0)  be  desired,  it  may  be  obtained  by  subtracting  the 
result  of  (3)  from  that  of  (2).  In  each  of  the  above  titrations  the 
number  of  cc.  of  alkaline  solution  used,  multiplied  by  0.0365,  gives 
the  result,  expressed  in  percentage  of  HCl. 

Martins  and  Luttlte's  Method. —  Four  samples  of  10  cc.  each  of 
the  filtered  material  are  taken.  In  (1),  the  total  chlorin  (T)  is  deter- 
mined either  volumetrically  with  a  N/10  solution  of  AgNOs  and 
thiocyanate  as  an  indicator,  or,  preferably,  gravimetrically,  by  the 
usual  methods.  The  result,  expressed  in  terms  of  HC1=(T),  consists 
of  free  HCl  (L),  protein  HCl  (C),  and  chlorin  in  chlorids  (F).  In 
the  second  10  cc.  (2),  the  chlorids  (F)  are  determined  by  evaporating 
to  dryness,  incinerating  at  dull  redness,  redissolving  in  water,  and 
determination  of  HCl  as  in  (l).  The  effective  HCl  (L+C)  is  deter- 
mined by  subtracting  (F)  from  (T).  In  the  third  sample  (3),  the 
total  acidity  (A)  is  determined  by  titration  with  N/10  NaHO  solution 
and  phenolphthalein.  The  acidity  due  to  organic  acids  (O)  is  arrived 
at  by  subtracting  (L+C)  from  (A).  In  the  fourth  sample  (4)  the 
free  HCl  (L)  is  directly  determined  by  titration  with  N/10  NaHO, 
using  dimethyl -amido-azobenzene  as  the  indicator.  Finally,  the 
value  of  (C)  is  obtained  by  subtracting  (L)  from  (L+C). 

Lactic  Acid. —  The  presence  of  lactic  acid  is  detected  by:  (1) 
Ufflemann's  reagent,  which  consists  of  a  solution  of  Fe2Cle  and  phenol, 
diluted  to  an  amethyst -blue  color,  which  is  changed  to  yellow  by 
lactic  acid.  In  order  to  avoid  error  by  the  action  of  other  substances 
which  have  a  like  action  upon  the  reagent,  10  cc.  of  the  filtered 
gastric  contents  are  agitated  with  ether,  and  the  ethereal  extract 
separated  and  agitated  with  the  reagent;  or  it  may  be  evaporated, 
the  residue  dissolved  in  water,  and  the  solution  added  to  the  reagent. 
(2)  Boas'  method,  which  is  more  reliable,  and  which  depends  upon 
the  formation  of  aldehyde  from  lactic  acid  by  the  action  of  oxidants 
(p.  292),  and  the  behavior  of  aldehyde  with  Nessler's  solution 
(p.  105).  Ten  cc.  of  the  contents  are  treated  with  excess  of  BaCOs, 
and  evaporated  to  dryness  on  the  water  bath,  to  a  syrup;  this  is 
treated  with  dilute  HaPCU,  heated  to  boiling,  cooled,  and  extracted 
with  ether  by  agitation.  The  separated  ethereal  extract  is  evaporated 
and  the  residue  extracted  with  water.  The  aqueous  solution  is  then 
mixed  with  5  cc.  H2$O4  and  a  little  Mn(>2,  and  distilled,  the  distillate 


524  MANUAL    OP    CHEMISTRY 

being  received  in  a  cylinder  containing  Nessler's  reagent,  which  is 
turned  yellow,  or  deposits  a  yellow -red  precipitate,  if  aldehyde  be 
present.  Or  the  distillate  may  be  received  in  a  N/10  normal  solution 
of  iodin,  with  which  aldehyde  forms  iodoform,  recognizable  by  its 
odor,  or  by  the  formation  of  a  yellow,  crystalline  precipitate,  if  the 
quantity  be  sufficient. 

If  the  iodin  solution  be  used,  the  process  may  be  made  a  quanti- 
tative one  by  determining  the  amount  of  unused  iodin  by  titration 
with  N/10  sodium  arsenite  solution. 

The  presence  of  butyric  acid  may  be  recognized  by  extracting 
10  cc.  with  50 cc.  of  ether  by  agitation,  evaporating  spontaneously, 
and  adding  a  few  drops  of  water  and  some  solid  CaCl2  to  the  solution, 
when  oily  drops  separate,  and  the  characteristic  odor  of  butyric  acid 
is  developed.  The  quantity  of  volatile  acids,  butyric  and  acetic,  may 
be  ascertained  by  determining  the  total  acidity  in  one  sample  of 
10  cc.  by  the  method  given  above;  evaporating  another  sample  of  10 
cc.  to  a  syrup,  redissolving  in  water,  and  determining  the  acidity  of 
the  solution.  The  difference  between  the  two  determinations  is  the 
acidity  due  to  volatile  acids. 

Pepsin  and  Pepsinogen. — If  free  HC1  be  present  the  gastric  con- 
tents are  examined  for  the  presence  of  pepsin  by  placing  about  .05 
gm.  of  coagulated  white  of  egg,  cut  into  discs  or  cubes,  in  25  cc.  of 
the  material,  which  is  then  kept  at  38-40°.  Digestion  should  be 
complete  in  about  three  hours,  or  the  edges  of  the  fragments  rounded 
perceptibly  in  less  time.  If  no  free  HC1  be  present,  pepsinogen  is 
tested  for  as  above,  five  drops  of  dilute  HC1  having  been  added  to  the 
material.  Should  the  result  be  negative,  200  cc.  of  N/10  HC1  should 
be  introduced  into  the  stomach,  the  contents  of  which  are  removed 
in  half  an  hour  and  tested  as  above. 

No  quantitative  method  of  determining  pepsin  is  possible  at 
present.  Comparisons  of  the  degrees  of  activity  of  a  given  sample  of 
gastric  contents  with  some  pharmaceutical  pepsin  may  be  made  by 
adding  5  cc.  of  the  former  and  0.5  gm.  of  the  latter  in  two  tubes  to 
10  cc.  of  a  1%  solution  of  serum  albumin  containing  3  p/m  of  HC1, 
and  after  24  hours  determining  the  amount  of  albumin  remaining 
undigested,  by  the  usual  methods  (p.  601). 

The  presence  of  chymosin  is  tested  for  by  keeping  a  mixture  of  5 
drops  of  gastric  contents,  and  10  cc.  of  milk  at  38-40°  for  15  minutes. 
If  the  milk  be  not  curdled  in  that  time,  the  zymogen  is  tested  for  by 
repeating  the  experiment  with  a  mixture  of  10  cc.  of  gastric  contents, 
10  cc.  of  milk,  and  3  cc.  of  a  1%  solution  of  CaCta 

Sometimes  it  is  desirable  to  test  the  stomach  contents  for  the 
products  of  digestion.  This  is  done  as  follows  :  The  filtered  con- 
tents are  accurately  neutralized  with  dilute  NaHO,  using  litmus  as  an 


: 


THE   BILE  525 

ndicator;  if  syntonin  be  present,  it  will  form  a  precipitate,  soluble 
excess  of  acid  or  of  alkali.  The  liquid,  freed  from  syntonin,  is 
acidulated  with  very  dilute  acetic  acid,  and  an  equal  volume  of  satu- 
rated NaCl  solution  is  added,  and  the  mixture  heated  to  boiling;  a 
coagulation  indicates  the  presence  of  native  albumens.  A  part  of 
the  filtrate  is  tested  for  primary  albumoses  by  addition  of  HNOa  and 
heating;  a  precipitate  in  the  cold,  which  disappears  with  heat,  and 
returns  on  cooling,  indicates  their  presence.  Another  portion  of  the 
filtrate  is  tested  for  secondary  albumoses,  which  are  precipitated,  if 
not  present  in  too  small  amount,  by  saturation  with  NaCl.  The 
mainder  of  the  filtrate  is  saturated  with  (NELihSC^,  filtered,  treated 
with  concentrated  NaHO  solution  in  slight  excess,  allowed  to  settle, 
decanted,  and  the  clear  liquid  tested  for  peptones  with  a  few  drops  of 
a  2%  CuSO4  solution,  which  gives  a  rose -red  or  reddish -violet  color 
in  the  alkaline  solution  if  they  are  present. 

Ewald's  test  for  the  activity  of  the  motor  function  of  the 
stomach  depends  upon  the  fact  that  salol  passes  through  the  stomach 
unchanged,  but  is  decomposed  in  the  intestine,  with  liberation  of 
salicylic  acid,  whose  presence  in  the  urine  may  be  then  detected. 
About  0.7  gm.  of  salol  are  administered  by  the  mouth,  and  the  urine 
is  collected  at  regular  intervals,  and  tested  by  addition  of  a  few  drops 
of  Fe2Cl6  solution,  which  gives  a  violet  color  with  salicylic  acid. 
The  reaction  should  appear  in  40  to  70  minutes,  and  should  cease  in 
30  hours.  The  resorptive  activity  of  the  stomach  may  be  tested  by 
administering  0.2  gm.  of  potassium  iodid  in  a  capsule,  and  testing 
the  saliva  every  two  minutes  by  moistening  a  test-paper,  made  by 
impregnating  filter -paper  with  starch  paste,  with  the  saliva,  and  then 
touching  it  with  a  glass  rod  dipped  in  yellow  HNOs,  which  turns  blue 
with  KI.  The  reaction  should  be  obtained  in  5-10  minutes. 


THE    BILE. 

The  bile  contained  in  the  gall-bladder  was  early  the  subject  of 
chemical  investigation.  It  may  be  obtained  from  living  animals  by 
temporary  biliary  fistulas. 

The  secretion  of  bile  is  continuous,  but  the  quantity  produced 
varies  greatly  at  different  times  and  in  different  individuals.  In  the 
dog  the  daily  production  has  been  found  to  vary  from  2.9  to  36.4 
grams  per  kilo  of  body -weight.  No  data  are  available  to  show  the 
amount  produced  in  24  hours  by  the  human  subject,  although  it  has 
been  estimated  at  500  to  950  grams,  and  also  at  14  gm.  per  kilo  of 
body -weight. 

The  secretion  of  the  liver  cells  is  thinner,  clearer,  and  of  lower 
sp.  gr.  than  the  bile  in  the  gall-bladder,  where  the  secretion  of  the 


526  MANUAL    OF    CHEMISTRY 

liver  becomes  mixed  with  the  mucus  of  the  gall-bladder.  The  bile 
contained  in  the  gall-bladder  is  cloudy,  somewhat  viscid,  alkaline; 
sp.  gr.  1,010  to  1,040;  bitter  in  taste,  having  a  faint,  musky  odor, 
particularly  perceptible  when  it  is  heated,  and  varying  in  color  from 
a  bright  golden-yellow  to  a  dark  olive -green.  In  man  it  is  usually 
yellow,  but  sometimes  green. 

Composition. — Several  analyses  of  specimens  of  human  bile  taken 
shortly  after  death,  or  from  biliary  fistulas,  have  been  made,  in  which 
the  numerical  results  have  varied  within  tolerably  wide  limits.  The 
proportions  of  solids  and  water  have  been  found  to  be  89.2  to  177.3 
of  the  former,  910.8  to  822.7  of  the  latter.  The  solids  consist  of 
mineral  salts,  less  than  1%,  "mucin"  1.3  to  3%,  biliary  salts  5.6  to 
10.8%,  cholesterol  0.16  to  0.35%,  fats  0.04  to  0.9%,  soaps  0.6  to 
1.6%,  and  bile  pigments,  lecithins  and  urea.  The  mineral  salts 
consist  of  the  chlorids  or  phosphates  of  Na,  K,  Ca,  Mg,  and  Fe. 
Copper  is  always  present  in  the  liver,  zinc  frequently,  and  both  may 
be  found  in  the  bile.  The  mucin  is  partly  a  true  mucin  (a  glyco- 
proteid)  and  partly  a  nucleoalbumen.  Urea  is  present  in  small 
amount  only,  but  is  found  in  large  quantity  in  the  bile  of  the  shark. 

Biliary  Salts. — The  bile  of  all  animals  contains  the  sodium  salts 
of  acids  peculiar  to  this  secretion.  They  vary  in  composition  in 
different  animals,  but  may  be  classed  in  two  groups,  the  members  of 
one  of  which  (glycocholic  series)  yield  glycocoll,  or  amido- acetic  acid 
(p.  363)  when  boiled  with  acids,  while  those  of  the  other  (taurocholic 
series)  yield  taurin,  or  amido -isethionic  acid  (p.  366)  under  like 
treatment.  The  other  product  of  the  decomposition  is,  in  both  cases, 
cholic  acid,  C24H4oO5,  whose  constitution  is  undetermined  beyond  the 
fact  that  its  molecule  contains  one  CHOH  group,  two  CEbOH  groups 
and  one  COOH  group.  It  crystallizes  in  octahedra  or  in  rhombic 
prisms,  is  easily  soluble  in  alcohol,  requires  4,000  parts  of  cold,  or 
750  of  hot  water  for  its  solution,  is  insoluble  in  ether,  and  becomes 
cloudy  on  exposure  to  air.  In  alcoholic  solution  it  is  dextrogyrous, 
Mo  =  +35°.  Its  Na  and  K  salts  are  readily  soluble  in  water; 
and  their  solutions  are  precipitated  by  lead  acetate,  or  by  barium 
chlorid.  Cholic  acid  is  easily  oxidized  or  reduced.  On  oxidation  it 
first  loses  He  to  form  dehydrocholic  acid,  C24Hs4O5,  a  crystalline, 
monobasic  acid,  sparingly  soluble,  which  does  not  respond  to  the 
Pettenkofer  reaction.  This  then  takes  up  oxygen  to  form  bilianic 
acid,  C24H3408;  and  this  is  then  converted  into  a  mixture  of  chol- 
esteric  acid,  C^HieO?,  and  pyrocholesteric  acid,  C^HieOs  (p.  529) .  By 
reduction,  it  yields,  first,  deoxycholic  acid,  C24H4oO4,  which  also  exists 
in  putrid  bile;  and  then  cholylic  acid,  C24H4oO2.  Two  other  acids, 
related  to  cholic  acid,  have  been  derived  from  human  bile,  one  choleic 
acid,  C^EUoO*,  possibly  identical  with  deoxycholic  acid;  the.  other 


THE  BILE  527 

fellic  acid,  C23H4oO4.  By  boiling  with  acids,  and  during  intestinal 
fermentation,  cholic  acid  loses  H2O  and  is  converted  into  an  anhy- 
drid,  dyslysin,  C24H36O3,  which  is  amorphous,  and  insoluble  in 
water  and  in  alkalies. 

Cholic  acid  and  the  conjugate  acids  containing  it  give  the  Petten- 
kofer,  or  furfurol,  reaction :  on  addition  of  a  few  drops  of  cane 
sugar  solution  and  then  of  concentrated  H2SO4,  the  temperature 
being  kept  down  to  about  70°,  the  solution  becomes  turbid,  and  soon 
assumes  a  fine  purple  color.  The  colored  liquid,  sufficiently  diluted 
with  acid,  gives  a  spectrum  of  two  bands,  one  at  F,  the  other  between 
D  and  E,  near  to  E.  With  H2SO4  alone  at  the  ordinary  temperature, 
solutions  of  the  biliary  acids  are  colored  reddish -yellow,  with  a  green 
fluorescence. 

Glycocholic  Acid — C26H43NO6 — predominates,  in  its  sodium  salt, 
in  human  bile  and  in  that  of  the  ox,  but  is  absent  in  that  of  the 
carnivora.  It  crystallizes  in  silky  needles,  soluble  in  300  parts  of 
cold,  and  120  parts  of  hot  water,  easily  soluble  in  alcohol,  insoluble 
in  ether,  which  precipitates  it  from  its  alcoholic  solution.  Its  taste  is 
at  the  same  time  bitter  and  sweet.  In  alcoholic  solution  it  is  dex- 
trogyrous  [a]D=-|-290.  Its  Na  salt  is  much  more  soluble  in  water 
than  the  free  acid,  and  its  solutions  are  precipitated  by  (C2H3O2)2Pb, 
CuSO4,  Fe2Cl6,  or  AgNO3.  When  heated  with  alkalies  or  dilute  acids, 
glycocholic  acid  is  decomposed  into  cholic  acid  and  glycocoll,  €26^3- 
NO6+H2O— C24H4oO5-f  CH2(NH2)  .COOH.  Heated  with  concentrated 
H2SO4  it  loses  water  to  form  cholonic  acid,  C26H4iNO5. 

Taurocholic  acid  —  C26H45NSO? — exists,  as  its  sodium  salt,  in 
human  bile  and  in  that  of  the  carnivora,  in  much  less  amount  in  that 
of  the  herbivora.  It  is  very  soluble  in  water  and  in  alcohol,  insoluble 
in  ether.  It  crystallizes  with  difficulty  in  silky  needles  by  precipita- 
tion of  its  solution  in  absolute  alcohol  by  anhydrous  ether.  These 
crystals  rapidly  deliquesce  to  an  amorphous,  resinous  mass  on  ex- 
posure to  air.  Its  taste  is  bitter  and  sweet.  In  alcoholic  solution  it 
is  laevogyrous,  [a]D=  — 24.5°.  Its  sodium  salt  is  very  soluble,  and 
its  solutions  are  not  precipitated  by  the  salts  which  precipitate  with 
glycocholic  acid,  but  it  is  precipitated  by  basic  lead  acetate.  Heated 
with  alkalies  or  dilute  acids,  or  even  on  evaporation  of  its  aqueous 
solution,  taurocholic  acid  is  decomposed  into  cholic  acid  and  taurin: 
C26H45NSO7+H2O  =  C24H4oO5  +  CH2(NH2)  .CH2.SO3H.  Solutions  of 
taurocholates  and  of  glycocholates  dissolve  cholesterol  and  alkaloids, 
if  the  salt  be  in  excess.  They  emulsify  oils. 

Biliary  Pigments — The  bile  of  all  animals  contains  peculiar  pig- 
ments, which  are  derivatives  of  the  blood -coloring  matter.  The  most 
important  are  bilirubin  and  biliverdin. 

Bilirubin — CieHis^Os— occurs  in  the  bile  of  all  vertebrates,  par- 


528  MANUAL    OF    CHEMISTRY 

ticularly  in  that  of  the  herbivora,  in  the  intestinal  contents,  in  biliary 
calculi,  and,  pathologically,  in  the  urine,  blood,  and  tissues,  and, 
crystallized  as  "haBinatoidin,"  in  old  extravasations  of  blood.  It 
forms  either  an  amorphous,  reddish -yellow  powder,  or  scarlet  crys- 
tals, or,  when  crystallized  by  spontaneous  evaporation  of  its  chlo- 
roform solution,  reddish -yellow  rhombic  plates.  It  is  insoluble  in 
water,  sparingly  soluble  in  alcohol  or  in  ether,  readily  soluble  in 
chloroform,  carbon  disulfid,  benzene,  and  in  alkaline  solutions,  with 
the  last  named  of  which  it  forms  soluble  compounds.  It  has  great 
pigmentary  power,  but  its  solutions  give  no  spectrum.  If,  however, 
its  alkaline  solutions  be  treated  with  ammonia,  in  excess  and  zinc 
chlorid,  they  change  in  color  to  deep  orange  and  then  to  green,  and 
then  give  a  spectrum  of  a  single  band  near  C,  and  between  C  and  D. 
By  the  action  of  sodium  amalgam  upon  a  solution  of  bilirubin  in 
weak  alkali  the  liquid  becomes  opaque,  and,  after  two  or  three  days, 
turns  brown,  when  upon  addition  of  HC1,  it  turns  red  and  deposits 
brown  flocculi  of  a  substance  which  closely  resembles,  if  it  is  not  iden- 
tical with,  the  stercobilin  of  the  fa3ces  and  the  urobilin  of  the  urine. 
This  substance,  which  is  called  hydrobilirubin,  Cs2H4oN4O7,  is  formed 
from  bilirubin  by  hydrogenation,  followed  by  oxidation  of  its  solution 
in  air:  2Ci6Hi8N2O3+3H2+O2=C32H4oN4O7-f  H2O.  Solutions  of  bili- 
rubin on  exposure  to  air  soon  become  green  from  formation  of 
biliverdin  by  oxidation. 

The  reactions  of  bilirubin  are  utilized  for  the  detection  of  bile  in 
the  urine  and  elsewhere.  They  are:  (1)  Gmelin's  reaction  —  The 
liquid  examined  is  floated  upon  the  surface  of  nitric  acid  containing 
a  little  nitrous  acid,  when  a  series  of  colors,  green,  blue,  violet,  and 
reddish -yellow,  are  produced  at  the  union  of  the  two  layers,  of  which 
the  green  is  the  most  marked.  There  must  be  no  alcohol  present. 
Limit  1:80,000.  This  reaction  depends  upon  a  progressive  oxidation, 
with  formation  of  the  following  products:  (a)  biliverdin  ;  (b)  bili- 
cyanin,  whose  neutral  solutions  are  of  a  fine  blue  color,  with  red 
fluorescence,  and  whose  alkaline  solutions  are  green,  and  give  a  spec- 
trum of  three  bands,  one  between  C  and  D,  nearer  to  C,  one  over  D, 
and  the  third  near  to  E,  between  E  and  F;  (c)  a  red  pigment,  the 
nature  of  which  has  not  been  determined;  (d)  choletelin,  a  brownish- 
yellow  pigment,  whose  alcoholic  solution  gives  a  spectrum  of  one 
band  between  E  and  F.  (2)  Hammarsten's  reaction — The  reagent 
used  is  made  by  mixing  1  vol.  HNOs  with  19  vols.  HC1,  and  letting 
the  mixture  stand  until  it  is  yellow.  A  colorless  liquid  is  formed  by 
mixing  1  vol.  of  this  reagent  with  4  vols.  of  alcohol,  which  is  colored 
intensely  green  by  a  trace  of  bilirubin.  (3)  Huppert's  reaction — The 
liquid  is  treated  with  calcium  chlorid  and  ammonia;  and  the  precip- 
itate formed  is  washed  with  water,  and  covered  while  still  moist  in  a 


THE   BILE  529 

test-tube  with  alcohol  and  acidulated  with  hydrochloric  acid,  which  is 
then  heated  to  boiling.  In  presence  of  bilirubin  the  liquid  becomes 
emerald -green. 

Biliverdin  —  CieHig^CU  —  accompanies  bilirubin,  and  is  most 
abundant  in  green  biles.  It  is  amorphous,  insoluble  in  water,  ether 
or  chloroform,  soluble  with  a  green  color  in  alcohol  and  in  glacial 
acetic  acid,  or  with  a  brown  color  in  alkalies.  It  is  precipitated 
from  its  solutions  by  acids  and  by  salts  of  Ca,  Ba,  and  Pb.  It  re- 
sponds to  the  tests  for  bilirubin.  Reducing  agents  convert  it  into 
bilirubin;  oxidizing  agents  into  biliverdic  acid,  CsHgNO-t.  It  is 
best  obtained  by  oxidizing  bilirubin. 

Bilifuscin  is  a  brown,  amorphous  pigment,  occurring  in  biliary 
calculi  and  in  putrid  bile,  which  is  soluble  in  alcohol  and  in  alkalies, 
insoluble  in  water,  ether  or  chloroform.  It  does  not  respond  to  the 
Gmelin  reaction.  Biliprasin  is  the  name  given  to  a  green  pigment 
occurring  in  biliary  calculi,  which  is  probably  a  mixture  or  combina- 
tion of  bilirubin  and  biliverdin.  Bilihumin  is  a  brown,  amor- 
phous pigment,  obtained  from  biliary  calculi,  which  is  insoluble  in 
alcohol,  ether  or  chloroform,  and  which  does  not  give  the  Gmelin 
reaction. 

Cholesterol  —  Cholesterin  —  C27H430H  —  is  a  monoatomic  alcohol 
of  unknown  constitution,  which  exists  normally  in  almost  every 
animal  tissue  and  fluid,  in  many  in  very  minute  quantity,  most  abun- 
dantly in  the  bile,  nerve  tissues,  intestinal  contents,  faBces,  and  in 
sebum  and  wool -fat.  In  pathological  products  it  is  frequently  an 
abundant  constituent,  and  is  met  with  in  biliary  calculi,  certain  brain 
tumors,  atheromatous  degenerations,  pus,  the  fluids  of  cysts,  hydro- 
cele,  etc.,  as  well  as  in  cancerous  and  tubercular  deposits,  and  in 
the  lens  in  cataract.  In  some  of  these  situations  it  exists  free,  in  its 
peculiar,  crystalline  form  of  very  thin,  colorless,  rhombic  plates,  while 
in  others  it  is  in  combination  in  the  form  of  its  enters.  It  also 
exists  in  the  vegetable  world,  widely  distributed,  notably  in  peas, 
beans,  olive-oil,  wheat,  etc. 

Cholesterol  is  insoluble  in  water,  in  alkalies,  or  in  dilute  acids, 
difficultly  soluble  in  cold  alcohol,  readily  soluble  in  hot  alcohol,  ether, 
benzene,  acetic  acid,  glycerol,  and  solutions  of  the  biliary  acids.  It 
is  odorless  and  tasteless;  f .  p.  145°  '293°  F.);  sp.  gr.  1.046.  It  is 
laevogyrous,  [a]D= — 31.6°,  in  any  solvent.  It  combines  readity 
with  volatile  fatty  acids,  and  from  its  solution  in  glacial  acetic 
acid  a  compound,  C27H43O.C2H3O2,  crystallizes  in  fine  curved  needles, 
which  are  decomposed  on  contact  with  water  or  alcohol.  When 
heated  with  acids  under  pressure,  it  forms  true  esters,  some  of  which 
also  exist  in  wool -fat,  and  in  "lanolin,"  derived  therefrom.  By  oxi- 
dation it  yields  a  series  of  acids,  from  cholesteric  acid, 
34 


530  MANUAL    OF    CHEMISTRY 

not  identical  with  the  acid  of  the  same  name  derived  from  cholic  acid 
(p.  526) — to  trioxycholesteric  acid,  C26H420?. 

Cholesterol  may  be  recognized  by  the  following  characters:  (1) 
Its  crystalline  form,  thin  rhombic  plates,  usually  having  one  obtuse 
angle  missing.  (2)  If  these  crystals  be  moistened  with  dilute  H2SO4 
(1:5)  they  are  colored,  first  bright  carmine,  and  then  violet,  begin- 
ning at  the  borders.  If  iodin  solution  be  now  added,  the  color 
changes  to  bluish -green,  then  to  blue.  (3)  When  EbSCU  is  added  to 
a  solution  of  cholesterol  in  chloroform,  the  liquid  is  colored  purple, 
changing  during  evaporation  to  blue,  green  and  yellow  (Salkowski). 

(4)  If  acetic  anhydrid  be  added  to  a  chloroform  solution  of  choles- 
terol, and  then  a  drop  or  two  of  concentrated  H^SOi,  the  mixture 
becomes  first  red,  then  blue,  and  finally  green  (Liebermann-Burchard) . 

(5)  When  a  mixture  of  2-3  vols.  of  H2SO4  or  HOI  and  one  vol.  of 
dilute  Fe2Cl6  solution  is  evaporated  upon  cholesterol,  a  residue  is 
obtained  which  is  at  first  purple,  then  violet    (Schiff).     (6)  When 
moistened  with  concentrated  HNOs  and  the  liquid  evaporated,  choles- 
terol leaves  a  yellow  residue,  which  is  colored  dark  orange -red  by 
NH4HO  or  NaHO  (see  Murexid  Reaction,  p.  355).     (7)  Pure,  dry 
cholesterol,  moistened  with  propionic  anhydrid  and  dried  and  fused, 
leaves  a  residue  which  on  ceoling  becomes  first  violet,  then  blue, 
green,  orange,  carmine -red,  and  finally  copper- colored  (Obermiiller). 

Isocholesterol  has  the  formula  C26H43OH,  formerly  assigned  to 
cholesterol.  It  occurs  in  wool -fat,  accompanying  cholesterol,  from 
which  it  differs  in  its  f.  p.  =138°  (280.4°  F.),  and  in  not  responding 
to  the  Salkowski  reaction. 

Origin  and  Destiny  of  the  Biliary  Constituents. —  The  biliary 
salts  are  produced  in  the  liver,  and  do  not  preexist  in  the  blood. 
This  is  proven  by  the  facts  that  they  do  not  accumulate  in  the  blood 
after  extirpation  of  the  liver  in  frogs,  and  that  in  dogs  they  are 
absorbed  by  the  lymphatics  of  the  liver  and  carried  to  the  blood  by 
the  thoracic  duct  after  ligation  of  the  ductus  choledochus,  but  they  do 
not  appear  in  the  blood  after  ligation  of  both  ductus  choledochus  and 
thoracic  duct.  Although  the  immediate  antecedents  of  the  biliary 
salts  are  not  known,  they  are  probably  formed  by  union  of  their 
constituents,  which  are  derived  from  different  sources.  Cholic  acid, 
containing  neither  nitrogen  nor  sulfur,  and  containing  both  alcoholic 
and  carboxyl  groups,  is  in  all  probability  derived  from  a  carbohy- 
drate, or  possibly  from  the  fats.  Glycocoll  and  taurin  both  contain 
nitrogen,  and  the  latter  sulfur  also.  They  are,  consequently,  derived 
from  the  proteins.  Glycocoll  is  one  of  the  principal  products  of 
decomposition  of  collagen  and  other  albuminoids,  although  it  has 
not  been  obtained  from  the  true  albumens  (p.  508).  The  biliary 
salts  are  not  reabsorbed  unchanged  from  the  intestine  under  normal 


THE    BILE  531 

circumstances,  or,  at  all  events,  not  in  any  notable  quantity.  Solu- 
tions of  these  salts,  when  injected  into  the  circulation,  are  rather 
active  poisons.  In  -small  doses  they  cause  diminution  in  the  fre- 
quency of  the  pulse  and  of  the  respiratory  movements,  lowering  of 
the  temperature  and  arterial  tension,  and  disintegration  of  the  blood- 
corpuscles.  In  large  doses  (2-4gm.  to  a  dog),  they  produce  the 
same  effects  to  a  more  marked  degree,  and,  further,  epileptiform 
convulsions,  black  and  bloody  urine,  and  death.  These  effects  do 
not  follow  the  injection  of  the  products  of  decomposition  of  the 
biliary  acids,  except  cholic  acid,  and  with  that  the  symptoms  are 
much  less  marked.  Nor  are  the  biliary  salts  found  as  such  in  the 
fraces,  except  that  these  occasionally  contain  glycocholic  acid,  but 
never  taurocholic  acid,  which  is  more  readily  decomposed.  Some- 
times cholic  acid  or,  more  frequently,  dyslysin  occurs  in  the  faeces, 
but  not  glycocoll  or  taurin.  The  decomposition  of  the  biliary  salts 
which  occurs  in  the  intestine  is  due  to  fermentative  (bacterial) 
action,  as  the  contents  of  the  lower  intestine  in  the  foetus  contain 
notable  quantities  of  biliary  salts.  That  the  taurin  resulting  from 
the  decomposition  is  reabsorbed  is  demonstrated  by  the  fact  that  it 
appears  in  the  urine,  partly  in  its  own  form  and  partly  as  tauro- 
carbamic  acid,  formed  by  the  union  of  taurin  and  carbamic  acid: 
C2H7NSO3  +  C02NH3  =  C3H8N2SO4+H2O.  Equally  direct  proof  of 
the  reabsorption  of  glycocoll  is  not  at  hand;  but  the  ready  formation 
of  uric  acid  (p.  358)  and  of  hippuric  acid  (p.  425)  from  glycocoll 
render  it  probable  that  the  latter  substance  is  an  intermediate  product 
in  the  formation  of  the  other  two,  in  part  at  least,  in  the  economy. 

The  biliary  pigments  are  also  formed  in  the  liver,  and  do  not 
preexist  in  the  blood,  although  bilirubin  at  least  may  be  formed  in 
other  parts  of  the  body,  and  has  been  found  in  old  extravasations  of 
blood,  and  in  the  placenta.  The  formation  of  these  pigments  in  the 
liver  is  proven  by  the  following  facts:  in  pigeons,  the  biliary  pig- 
ments make  their  appearance  in  the  blood  in  five  hours  after  ligation 
of  the  bile -ducts;  but  if  the  blood-vessels  of  the  liver  are  ligated  at 
the  same  time,  no  pigments  appear  in  the  blood  or  tissues  in  24 
hours.  In  geese,  poisoned  with  hydrogen  arsenid,  the  biliary  pig- 
ments appear  in  the  urine  in  large  quantity;  but  if  the  liver  have 
been  extirpated  before  the  poisoning  this  does  not  occur. 

The  parent  substance  of  the  biliary  pigments  is  undoubtedly  the 
blood  coloring  matter.  The  chemical  relationship  between  bilirubin 
and  certain  derivatives  of  haemoglobin  is  very  close.  Indeed  bilirubin 
is  identical  with  haBmatoidin,  which  is  found  in  old  blood  stains,  and, 
in  the  crystalline  form,  in  old  extravasations  of  blood.  Bilirubin  is 
also  isomeric  with  haematoporphyrin,  a  pigment  normally  present  in 
the  urine  in  small  amount,  and  notably  increased  therein  in  poisoning 


532  MANUAL    OF    CHEMISTRY 

by  sulfonal.  The  relation  between  haematin  and  bilirubin  is  shown  by 
the  equation:  C32H32N4FeO4-|-2H20=2Ci6Hi8N2O3+Fe,  which  may,  in 
some  modified  form,  indicate  the  method  of  formation  of  the  biliary 
pigment.  The  iron  thus  liberated  has  been  accounted  for  only  in 
part.  The  bile  always  contains  iron,  principally  in  the  form  of  ferric 
phosphate,  to  the  proportion  of  from  0.04  to  0.115  p/m.  But  the 
correspondence  between  the  amount  of  iron  present  and  the  amount 
of  bilirubin  formed,  which  the  above  equation  would  call  for,  has  not 
been  found  to  exist.  For  100  parts  of  bilirubin  present  in  the  bile, 
1.4  to  1.5  parts  of  iron  have  been  found,  whereas  an  equivalent  quan- 
tity of  ha3matin  would  yield  9  parts.  Moreover,  in  poisoning  by 
hydrogen  arsenid,  in  which  there  is  an  increased  formation  of  bile 
pigment,  no  corresponding  increase  in  the  amount  of  iron  in  the  bile 
has  been  observed.  Probably  a  large  portion  of  the  iron  enters  into 
some  form  of  combination  as  a  protein  or  pigment,  from  which  the 
bilirubin  is  subsequently  derived. 

There  is  no  correspondence  in  the  observed  variations  in  the 
quantities  of  biliary  salts,  and  of  biliary  pigments  formed.  As  these 
variations  take  place  independently  of  each  other,  the  processes  of 
formation  of  the  two  classes  of  substances  may  be  considered  as  being 
distinct  from  each  other. 

The  biliary  pigments  are  not  reabsorbed  unchanged  in  health. 
When  they  are  pathologically  (icterus,  phosphorus  poisoning)  they 
stain  the  skin  and  tissues,  and  make  their  appearance  in  the  urine. 
The  coloring  matter  of  the  faeces,  stercobilin,  and  at  least  one  of 
those  of  the  urine,  urobilin,  are  derived  from  bilirubin  (p.  592). 

Cholesterol  exists  in  the  protoplasm  of  all  cells,  and  is  particu- 
larly abundant  in  nerve  tissues.  In  analyses  of  brain  substance  it 
has  been  found  to  constitute  a  large  portion  of  the  solid  constituents 
of  both  white  and  gray  matter,  particularly  of  the  former.  It  is  con- 
stantly present  in  the  faaces  in  its  own  form  or  in  that  of  a  derivative 
(koprosterin,  stercorin),  and  only  appears  in  the  urine  in  chyluria. 
It  is,  in  all  probability,  a  product  of  dissassimilation,  produced  prin- 
cipally in  nervous  tissues. 

Biliary  Calculi. — Calculi  are  frequently  met  with  in  the  gall 
bladder  after  death,  and  the  smaller  ones  often  pass  into  the  intestine 
during  life.  These  calculi  may  be  divided  into  three  classes,  accord- 
ing to  the  nature  of  their  chief  constituents  :  (1)  Pigmentary  calculi, 
consisting  chiefly  of  the  several  pigments  mentioned  above,  combined 
with  calcium,  and  sometimes  associated  with  calcium  salts.  They  are 
usually  multiple,  sometimes  very  numerous.  They  are  yellow,  green, 
brown  or  black  in  color;  sometimes  rounded  and  nodulated  upon 
their  surfaces,  more  usually  having  flattened  surfaces,  and  more  or 
less  perfect  geometrical  shapes,  produced  by  attrition  one  against  the 


PANCREATIC    SECRETION 


533 


other.  In  cattle  these  stones  are  sometimes  found  as  large  as  a 
walnut.  (2)  Cholesterol  calculi,  consisting  almost  entirely  of  choles- 
terol. They  are  usually  single,  rounded  and  polished,  having  a 
nacreous  appearance  and  an  ovoid  outline.  They  may  measure 
nearly  an  inch  in  their  longer  diameter.  (3)  Calcic  calculi  are  much 
more  rare  in  the  human  subject  than  the  other  two  forms.  They 
consist  mainly  of  tricalcic  phosphate  and  calcium  carbonate. 


PANCREATIC   SECRETION. 

The  secretion  of  the  pancreas  can  be  obtained  from  temporary 
fistulae  in  animals,  or  permanent  fistulae  may  also  be  established, 
but  the  secretion  obtained  from  the  latter  generally  becomes  changed 
from  the  normal  in  composition  in  a  few  hours.  Its  secretion  is 
normally  continuous  in  the  herbivora,  but  interrupted  in  the  car- 
nivora,  and  in  the  herbivora  during  starvation.  The  maximum  of 
secretion  is  reached  in  about  three  hours  after  eating,  with  another 
rise  from  two  to  four  hours  later.  In  dogs  the  amount  secreted  is 
estimated  at  22  cc.  per  kilo,  of  body  weight.  The  pancreatic  juice 
of  the  dog  is  clear,  colorless,  odorless,  slightly  viscid,  sp.  gr.  1008 
to  1010,  and  strongly  alkaline,  the  alkalinity  being  equal  to  about 
3  p/m  of  Na2CO3. 

Composition. —  The  secretion  from  a  temporary  fistula  in  the 
dog  contains:  water,  900.8;  solids,  99.2.  The  solids  consist  of 
mineral  substances  8.8,  and  organic  substances  90.4.  The  pancreatic 
secretion  found  in  an  occluded  canal  of  Wirsung,  in  a  man  suffering 
from  cancer,  contained  a  much  smaller  quantity  of  solids:  24.1  p/m, 
of  which  11.5  p/m  consisted  of  peptones  and  enzymes,  and  6.2  p/m 
of  salts  (Herter). 

The  mineral  constituents  are  sodium  and  potassium  chlorids  and 
phosphates,  sodium  and  potassium  carbonates,  to  which  the  liquid 
owes  its  alkalinity,  and  compounds  of  calcium,  magnesium  and  iron. 
The  organic  constituents  include  a  little  leucin,  fat,  and  soap,  much 
albumen,  sufficient  to  cause  the  liquid  to  form  a  solid  coagulum  when 
it  is  heated,  and  at  least  three  enzymes,  one  a  proteolytic  enzym, 
trypsin,  another  an  amylolytic  enzym,  pancreatic  diastase,  and  the 
third  having  a  saponifying  action,  steapsin. 

Trypsin.— This  enzym  does  not  exist  in  the  gland,  which  contains 
a  zymogen,  from  which  the  enzym  is  produced  by  the  action  of  water, 
acids,  alcohols,  etc.  The  product  most  nearly  approaching  purity 
is  probably  that  obtained  by  Kiihne's  method,  which  consists  essen- 
tially of  precipitation  by  alcohol  and  subsequent  purification.  It  is 
very  soluble  in  water,  insoluble  in  alcohol  or  in  glycerol,  although 
if  less  pure  it  dissolves  in  glycerol,  which  may  be  used  to  obtain 


534  MANUAL    OF    CHEMISTRY 

an  active  extract  of  the  pancreas.  In  aqueous  solution  it  is  decom- 
posed into  a  coagulated  albumen  and  peptone  by  addition  of  a  little 
acid  and  boiling.  The  relatively  pure  euzym  is  destroyed  in  five 
minutes  in  solution  containing  0.5%  NaHO,  at  50°.  In  neutral 
solution  it  is  destroyed  at  45°,  less  rapidly  in  presence  of  albumoses. 
The  characteristic  property  of  trypsin  is  its  power  of  dissolving  coagu- 
lated proteins  in  alkaline  or  in  extremely  faintly  acid  solution.  Its  ac- 
tion upon  fibrin  is  the  most  energetic,  but  it  also  dissolves  coagulated 
albumins  and  globulins  rapidly,  and  gelatin,  which  is  not  dissolved  by 
pepsin,  as  well.  It  acts  best  in  the  presence  of  3  to  4  p/m  of  Na2COa. 
Its  action  is  arrested  by  the  presence  of  even  very  small  quantities  of 
mineral  acids,  but  not  by  protein -hydrochloric  acid  (p.  522).  Or- 
ganic acids  cause  less  interference,  and  lactic  acid  in  the  proportion 
of  0.2  p/m  in  presence  of  bile  and  NaCl,  none  whatever.  Its  action 
is  diminished  by  accumulation  of  its  products.  It  is  very  prone  to 
putrefaction.  Trypsin  is  more  active  and  causes  greater  changes 
than  pepsin.  As  indicated  above  (p.  519),  it  decomposes  the  ampho- 
peptone  of  peptic  digestion  into  anti- peptone  and  hemi- peptone. 
Independently  of  peptic  action,  and  if  putrefaction  be  prevented  by 
operating  in  liquids  containing  a  little  thymol  or  chloroform,  it 
produces  from  albumin  or  fibrin  albumoses,  peptones,  leucin,  tyro- 
sin,  aspartic  acid,  and  even  lysin,  lysatinin,  arginin  and  histidin 
(p.  499).  During  the  action  of  trypsin  upon  albumin  a  substanee 
called  proteinochromogen,  or  tryptophan,  is  also  produced.  This 
body  produces,,  with  chlorin  or  bromin,  a  reddish -violet  derivative, 
proteinochrom,  which  is  very  unstable  and  highly  diffusible.  The 
bromin  derivative  is,  apparently,  related  to  haematoprophyrin  and 
to  bilirubin. 

Trypsin  in  alkaline  solution  coagulates  milk,  decomposes  the 
nucleins,  pseudonucleins,  glycoproteids  and  haemoglobins,  with 
solution  of  the  albumens  liberated,  and  converts  gelatin  into 
gelatopeptones.  Collagen  is  not  affected,  unless  previously  acted 
upon  by  acids  (p.  508).  It  does  not  act  upon  keratin  or  upon  chitin. 

Pancreatic  diastase,  also  called  amylopsin,  does  not  exist  in  the 
pancreatic  secretion  of  infants,  and  only  makes  its  appearance  after 
the  first  month  of  life.  It  is  very  similar  to  ptyalin,  but  probably 
not  identical  with  that  enzyin.  Its  action  upon  cooked  starch  is 
very  energetic,  and  it  also  decomposes  raw  starch  more  slowly  at 
37°  to  40°.  The  products  of  its  action  upon  starch  are  dextrin, 
isomaltose  and  maltose,  with  very  little  glucose. 

Steapsin  is  the  saponifying  enzym  of  the  pancreatic  secretion. 
It  decomposes  the  neutral  fats  into  glycerol  and  fatty  acid,  the 
latter  combining  with  the  alkalies  present  to  form  soaps.  It  is 
thus  also,  indirectly,  an  emulsifying  agent. 


INTESTINAL    SECRETIONS,   ETC.  535 


INTESTINAL    SECRETIONS. 


The  "intestinal  juice,"  succus  entericus,  is  the  product  of  a  great 
number  of  small  glands,  including  Brunner's  glands,  Lieberkiihn's 
follicles,  Peyer's  patches  and  the  solitary  glands.  Its  study  is  at- 
tended with  great  difficulty,  not  only  because  it  can  only  be  obtained 
from  portions  of  the  intestine,  by  isolating  a  portion  of  the  gut  in 
animals,  or  by  the  occurrence  of  artificial  anus  in  the  human  sub- 
ject, but  also  because  of  the  difficulty  in  determining  what  portion 
of  the  observed  actions  are  due  to  the  secretion  of  these  glands  and 
what  to  bacterial  action,  etc.  About  all  known  concerning  it  is 
that  it  has  an  alkaline  reaction  equivalent  to  4  to  5  p/m  of  Na2COs; 
that  it  contains  albumin,  albumoses  and  a  mucin;  that  it  does  not 
act  upon  the  proteins,  has  but  a  slight  action  upon  cooked  starch, 
and  does  not  saponify  fats.  Its  most  prominent  action,  supposed 
to  be  caused  by  an  enzym,  invertin,  is  that  of  inverting  the  disac- 
charids,  saccharose,  maltose  and  lactose  (p.  270).  It  also  aids  in 
the  emulsification  of  the  fats,  in  presence  of  proteins  and  of  an 
alkaline  reaction. 

CHEMICAL   CHANGES   OCCURRING  IN   THE   INTESTINE. 

The  changes  which  the  constituents  of  the  food  undergo  in  the 
alimentary  canal  are  the  sum  of  the  effects  produced  by  the  several 
digestive  secretions,  modified  by  their  influences  upon  each  other's 
actions,  and  the  chemical  reactions  set  up  by  bacterial  life,  constantly 
present  and  active.  The  changes  in  the  organic  food -constituents, 
carbohydrate,  fatty  and  protein,  are  briefly  the  following: 

Carbohydrates. — The  amylolytic  action  of  the  ptyalin  of  the  saliva 
upon  hydrated  starch  is  arrested  by  the  acid  reaction  of  the  gastric 
contents,  but  may  continue  for  some  little  time  in  the  stomach  in  the 
interior  of  difficultly  permeable  masses  of  starchy  foods,  particularly 
as  a  certain  degree  of  acidity  is  required  to  arrest  the  action.  But 
once  arrested,  it  is  not  reestablished,  so  far  as  salivary  action  is 
concerned,  when  the  reaction  returns  to  alkaline  in  the  intestine.  In 
the  intestine  the  powerful  diastatic  action  of  the  pancreatic  enzym, 
favored  by  the  presence  of  the  bile,  takes  the  place  of  salivary  action 
and  continues  the  amylolytic  hydrolysis  to  the  formation  of  disac- 
charids.  Inversion  of  the  disaccharids,  cane-sugar,  milk-sugar,  and 
maltose,  is  effected  by  the  invertin  of  the  intestinal  secretion,  and 
also  by  bacterial  action.  Even  cellulose,  if  finely  divided,  is  to  some 
extent  converted  into  soluble  derivatives  in  the  intestine,  but  by 
what  agency  is  unknown. 

Fats. — The  known  chemical  change  which  the  fats  undergo  during 


536  MANUAL    OF    CHEMISTRY 

digestion  is  limited  to  a  not  very  abundant  saponification,  caused  by 
the  pancreatic  enzym.  The  liberated  fatty  acids  combine  in  part  with 
the  alkali  of  the  bile  and  of  the  pancreatic  juice  to  form  soaps,  which 
favor  the  conversion  of  the  remainder  of  the  fats  into  the  form  of 
emulsion  in  which  they  are  absorbed  by  the  lacteals. 

Proteins. — The  chyme,  more  or  less  strongly  acid  in  reaction, 
and  rich  in  albumoses  and  ampho- peptones,  the  products  of  peptic 
digestion,  is  greatly  modified  shortly  after  its  passage  into  the  duo- 
denum, where  an  entirely  different  series  of  processes  are  begun. 
The  albumens  and  acid  albumens  of  the  gastric  contents  are  precipi- 
tated by  the  bile  in  acid,  not  in  alkaline  reaction,  that  is  by  the  free 
biliary  acids,  and  notably  by  taurocholic  acid,  but  not  by  the  biliary 
salts.  Peptones  are  not  so  precipitated.  But  the  protein  precipitate 
formed  by  the  bile  is  redissolved  by  an  excess.  It  is  doubtful 
whether  this  precipitation  occurs  to  any  considerable  extent  in  the 
human  subject,  in  whom  the  alkalinity  of  the  bile  and  pancreatic 
secretion,  discharged  into  the  intestine  by  a  common  opening,  soon 
overcomes  the  acidity  of  the  chyme.  So  soon  as  the  reaction  passes 
from  acid  to  alkaline,  peptic  digestion  ceases,  and  the  more  energetic 
tryptic  digestion  takes  its  place,  causing  the  t eduction  of  the  albu- 
moses and  ampho -peptones  to  simpler  forms  of  combination.  Here 
also  fermentative,  or  bacterial,  changes  begin,  to  continue  throughout 
the  intestinal  tract.  As  a  result  of  bacterial  action  upon  the  carbo- 
hydrates, lactic  acid  and  acids  of  the  acetic  series  are  produced, 
which,  in  their  turn,  gradually  overcome  the  alkalinity  caused  by  the 
bile  and  pancreatic  secretion,  until,  in  the  lower  ileum,  the  reaction 
again  becomes  acid,  to  continue  so  throughout  the  remainder  of  the 
intestine.  But  the  acids  here  generated  are  not  such  as  interfere 
with  tryptic  digestion,  in  the  amounts  in  which  they  are  formed 
(p.  534).  Bacterial  action  is  most  intense  in  the  upper  part  of  the 
large  intestine,  and  diminishes  as  water  is  removed  by  absorption. 
The  products  of  intestinal  putrefaction  (for  the  process  is  very  similar 
to  anaerobic  putrefaction  outside  the  body)  are:  albumoses,  peptones, 
amido-acids,  ammonia,  indole,  skatole,  phenol,  paracresol,  phenylic 
acids,  volatile  fatty  acids,  mercaptan,  hydrogen  sulfid,  carbon  dioxid, 
metharfe,  and  hydrogen.  These  are  partly  discharged  with  the  faeces 
and  intestinal  gases,  but  are  also  in  large  part  reabsorbed.  Several 
reappear  in  the  urine  in  forms  modified  by  oxidation,  or  by  synthetic 
processes.  Indole,  skatole,  and  phenol,  for  example,  exist  in  syn- 
thetic derivatives  in  the  urine,  and  the  amount  of  the  indole  deriva- 
tive, indican,  eliminated  by  the  urine,  is  an  index  of  the  extent  of 
reabsorption  of  the  products  of  intestinal  bacterial  action  occurring 
at  the  time.  Certain  constituents  of  the  digestive  secretions  are 
themselves  modified  by  bacterial  action.  Thus  the  biliary  pigments 


CHEMICAL    CHANGES    OCCURRING    IN    THE    INTESTINE        537 

are  converted  into  stercobilin  or  urobilin,  and  the  biliary  acids  are 
split  into  their  factors. 

The  intensity  of  bacterial  action  is  held  in  check  by  three  agencies : 
by  the  removal  of  water  and  of  the  products  of  digestion  by  absorp- 
tion, by  the  antiseptic  action  of  the  biliary  acids,  and  by  the  increase 
in  the  amount  of  lactic  acid.  Taurocholic  acid  prevents  putrefaction 
and  fermentation  when  present  in  the  proportion  of  0.2%  to  0.5%. 
Glycocholic  acid  is  much  less  active  in  this  respect. 

Intestinal  Gases. — The  gases  of  the  intestine  consist  largely  of 
nitrogen,  derived  from  swallowed  air.  Oxygen  exists  only  in  very 
small  amount,  having  been  absorbed  either  by  the  host  or  by  the 
bacteria.  Carbon  dioxid  is  constantly  present  in  notable  amount, 
produced  by  putrefaction  of  the  proteins,  by  fermentative  decom- 
position of  the  carbohydrates,  and  by  neutralization  of  the  sodium 
carbonate  of  the  bile  and  pancreatic  juice.  Hydrogen  is  formed  by 
bacterial  growth.  Minute  quantities  of  hydrogen  sulfid,  resulting 
from  decomposition  of  the  proteins;  and  of  methane,  from  decom- 
position of  both  proteins  and  carbohydrates,  are  also  present. 

Faeces.  —  All  substances  taken  into  the  mouth,  which  are  not 
either  dissolved  and  absorbed,  or  vomited,  must  appear  in  the  faeces. 
These  are,  therefore,  the  more  abundant  the  greater  the  amount  of 
indigestible  material,  cellulose,  keratin,  etc.,  contained  in  the  food. 
The  fasces  may  also  contain  slowly  digestible  material,  shreds  of 
muscular  tissue,  starch,  coagulated  casein,  fat,  which  have  escaped 
digestion  by  a  too  rapid  passage  through  the  alimentary  canal,  or 
from  having  been  taken  in  excessive  amount.  Besides  the  undigested 
food  residues,  the  fseces  contain  substances  formed  in  the  body 
either  by  its  own  action  or  that  of  the  fauna  and  flora  inhabiting 
the  alimentary  canal.  These  consist  of  morphological  elements  de- 
rived from  the  mucous  membranes  and  glands;  mucins,  cholesterol 
(excretin,  stercorin),  cholic  acid,  dyslysin,  stercobilin  and  mineral 
salts  derived  from  the  bile  and  other  secretions;  indole,  skatole  and 
other  products  of  bacterial  life,  and  the  micro-organisms  themselves; 
sometimes,  also,  entozoa  or  their  ova,  pathogenic  microbes,  and  in- 
soluble residues  of  medicinal  substances.  The  reaction  of  the  faeces 
of  adults  is  alkaline,  the  acidity  due  to  the  volatile  fatty  acids  and 
lactic  acid,  produced  by  putrefactive  changes,  having  been  more  than 
overcome  by  the  alkalinity  of  the  ammonia  and  amins,  produced  by 
ammoniacal  fermentations.  In  nursing  infants,  in  whom  a  consid- 
erable quantity  of  lactic  acid  is  formed  from  the  milk-sugar,  the 
reaction  is  acid.  The  normal  color  of  the  faeces  is  due  to  stercobilin 
(hydrobilirubin),  derived  from  the  biliary  pigments.  When  the  bile 
is  deficient,  the  faeces  are  pale  in  color,  and  contain  a  large  quantity 
of  fat.  The  faeces  are  sometimes  almost  black  in  color,  either  from 


538  MANUAL    OP    CHEMISTRY 

the  presence  of  hasmatin  or  haematoidin  after  haemorrhages,  or  from 
the  presence  of  dark -colored  metallic  sulfids  after  administration  of 
the  salts  of  iron,  bismuth  or  lead.  When  these  sulfids  are  present 
they  frequently  deposit  as  heavy,  dark -colored  powders  at  the  bot- 
tom of  the  vessel.  The  faecal  odor  is  largely  that  of  indole  and 
skatole,  somewhat  modified  by  the  odors  of  ammonia  and  of  hydrogen 
sulfid. 

Meconium  —  the  contents  of  the  lower  intestine  of  the  foetus 
at  birth — is  dark  brown  or  green  in  color,  almost  odorless,  acid  in 
reaction,  and  semi- solid  in  consistency.  It  contains  epithelial  cells, 
frequently  stained  green,  fat  globules,  crystals  of  cholesterol  and  of 
bilirubiu.  In  chemical  composition  it  consists  of  about  80%  water 
and  20%  solids.  The  solids  consist  of  mucin,  biliary  acids  and  pig- 
ments, cholesterol,  fat,  soaps,  peptones,  leucin,  tyrosin  and  salts, 
notably  calcium  and  magnesium  phosphates.  Stains  produced  by 
meconium  may  be  distinguished  from  faecal  stains  by  the  fact  that 
the  former  give  Gmelin's  and  Pettenkofer's  reactions,  while  the 
latter  do  not. 

Intestinal  Concretions.  —  Besides  gall-stones,  the  intestine  may 
contain  true  intestinal  concretions,  which  Ibe,  however,  of  much 
rarer  occurrence  in  the  human  subject  than  in  the  lower  animals. 
They  usually  consist  of  concentric  layers  of  calcium  carbonate  or 
of  tricalcic  phosphate,  with  a  little  fat  and  pigment,  deposited  upon 
some  insoluble  foreign  substance  as  a  nucleus,  or  they  may  be  formed 
in  the  vermiform  appendix  without  a  nucleus.  The  intestines  of 
horses  and  cattle  frequently  contain  large  calcic  calculi,  sometimes 
weighing  several  pounds  (16  Ibs.  in  a  horse);  or  "hair-balls,"  con- 
sisting of  masses  of  hair  agglutinated  into  hard  balls.  Bezoar  stones 
are  concretions  from  the  intestines  of  certain  goats  and  antelopes, 
which  contain  either  lithofellic  acid,  a  peculiar  acid  related  to  cholic 
acid,  or  ellagic  acid,  a  derivative  of  gallic  acid,  and  biliary  pigments. 
Ambergris  is  an  intestinal  concretion  of  the  whale,  containing  a 
non-nitrogenized  substance,  ambrain,  related  to  cholesterol. 

THE    BLOOD. 

The  blood  being  the  circulating  medium  by  which  oxygen  and 
the  products  of  digestion  are  carried  to  the  tissues,  and  by  which 
the  waste  products  of  tissue  metabolism  are  carried  -to  the  excretory 
organs,  varies  notably  in  composition  in  different  parts  of  the  cir- 
culation at  different  times  and  under  varying  conditions  of  health 
or  disease. 

The  living,  circulating  blood  consists  of  two  parts,  the  plasma, 
the  liquid  portion,  and  the  corpuscular  elements  suspended  therein. 


THE    BLOOD  539 

It  is  desirable  to  consider  the  chemistry  of  these  two  constituents 
of  the  blood  first,  and  subsequently  that  of  the  blood  as  a  whole. 

The  blood,  very  soon  after  being  removed  from  the  living  animal, 
undergoes  the  chemical  and  physical  change  of  coagulation,  involving 
modification  of  the  proteins  of  the  plasma,  and  the  separation  of  the 
blood  into  the  two  new  divisions  of  clot,  consisting  of  the  newly- 
formed  fibrin  and  the  corpuscles;  and  the  serum,  containing  those 
constituents  of  the  plasma  not  concerned  in  the  formation  of  fibrin. 
In  order,  therefore,  to  obtain  the  plasma  and  corpuscles  free  from 
each  other  some  method  must  be  adopted  to  prevent  the  occurrence 
of  coagulation  during  the  separation.  Several  methods  have  been 
used  for  this  purpose  : 

(1)  By  taking  advantage  of  the  fact  that  the  blood  of  the  horse 
coagulates  very  slowly  at  low  temperatures.     Horse's  blood  is  col- 
lected in  a  tall,  narrow  glass  vessel,  surrounded  by  a  freezing  mixture 
of  ice  and  salt,  which  is  then  maintained  at  0°  until  the  corpuscles 
have  settled.     Coagulation  does  not  take  place  for  several  days. 

(2)  On  a  small  scale  the  corpuscles  may  be  separated  from  the 
plasma  by  increasing  the  rapidity  of  their  deposition  by  the  use  of 
the  haemat6crit.     This  is  simply  a  centrifuge  revolving  with  great 
rapidity  (3,000  to  5,000  revolutions  a  minute).     With  the  very  nar- 
row tubes  used,  the  separation  is  complete  in  about  two  minutes,  and 
before  coagulation  has  interfered. 

(3)  The  centrifuge,  revolved  at  a  lower  speed,  may  be  also  used 
with  larger  quantities  of  blood,  but  then  some  agency  must  be  used 
to  delay  coagulation.     One  method  consists  in  injecting  a  solution 
of  albumose  into  the  circulation  of  a  dog,  collecting  the  blood  and 
centrifugating  it.     The  plasma  so  obtained  is  known   as  peptone- 
plasma.     Or  an  infusion  of  the  mouth  of  the  leech  may  be  similarly 
used. 

(4)  If  the  blood,  as  it  flows  from  the  vessel  be  mixed  with  either 
an  equal  volume  of  saturated  solution  of  sodium  sulfate,  or  with  the 
same  quantity  of  a  10%  sodium  chlorid  solution,  or  with  one -third  its 
volume  of  a  saturated  solution  of  magnesium  sulfate,  and  the  mix- 
ture maintained  at  a  low  temperature,  coagulation  will  be  delayed 
sufficiently  to  permit  the  corpuscles  to  settle.     This  plasma  is  called 
salt  plasma. 

(5)  The  best  method  depends  upon  the  removal  of  the  calcium 
salts,  whose  presence  is  necessary  to  coagulation,  by  precipitation  as 
calcium  oxalate.     The  blood  is  received  in  a  dilute  solution  of  po- 
tassium oxalate  in  such  proportion  that  the  mixture  contains  0.1%  of 
oxalic  acid,  and  the  mixture  set  aside  until  the  corpuscles  deposit. 
The  plasma,  known  as  oxalate  plasma,  regains  its  power  of  coagula- 
tion on  restoration  of  the  calcium  salts. 


540  MANUAL    OF    CHEMISTRY 


PLASMA    AND    SERUM. 

The  plasma,  at  the  temperature  of  0°,  above  which  it  rapidly 
coagulates  into  clot  and  serum,  is  a  viscid  liquid,  yellowish,  or 
greenish -yellow  in  color,  strongly  alkaline  in  reaction. 

Composition. — But  few  complete  analyses  of  blood-plasma  have 
been  made.  Indeed,  considering  the  variations  in  its  quantitative 
composition,  above  referred  to,  the  results  of  such  analyses  can  only 
be  considered  as  applying  to  the  particular  sample  analyzed,  and  not 
as  representing  the  mean  composition  of  the  plasma  except  in  a 
general  way.  The  following  are  results  obtained  from  horse's  blood, 
the  first  an  analysis  by  Hoppe-Seyler,  the  latter  the  mean  of  three 
analyses  by  Hammarsten  : 

I.  II. 

Water 908.4      .    .  917.6 

Solids 91.6  .    .    .    82.4 

69.5 
6.5 

38.4 
24.6 


12.9 


Fibrinogen,  the  parent  substance  of  fibrin,  exists  in  the  plasma, 
chyle,  lymph,  and  in  transudates  and  exudates.  It  has  the  charac- 
teristic property  of  coagulating  in  presence  of  calcium  salts  and  an 
enzym  (thrombin),  with  formation  of  fibrin.  When  moist,  it  forms 
viscid,  elastic  masses  or  flocks,  which  readily  fuse  together.  It  has 
the  general  properties  of  the  globulins,  from  which  it  differs  in  that 
the  addition  of  calcium  chlorid  solution  to  its  very  faintly  alkaline 
and  salt -free  solution  causes  a  precipitate  which  contains  calcium, 
and  soon  becomes  insoluble.  This  precipitate  is  not  formed  in  pres- 
ence of  sodium  chlorid,  nor  with  an  excess  of  calcium  chlorid. 
Fibrinogen  is  soluble  in  dilute  sodium  chlorid  solution,  and  this 
solution,  neutral,  or  very  faintly  alkaline,  coagulates  at  56°.  Its 
solutions  are  precipitated  by  addition  of  an  equal  volume  of  satu- 
rated sodium  chlorid  solution,  and,  completely,  by  excess  of  the  solid 
salt;  in  which  latter  respect  it  differs  from  serum -globulin.  It  de- 
composes hydrogen  peroxid  energetically.  Its  solutions  are  laevo- 
gyrous,  [a]D=  — 52.2°.  It  is  obtained  from  salt-  or  oxalate- plasma 
by  precipitation  with  an  equal  volume  of  saturated  salt  solution  and 
purification. 


Fibrinogen  

10.1      .    . 

Serum  globulin               ..... 

)              (  - 

Serum  ftlbuTniTi 

\  67-5   ;  . 

Pat              

j       i  • 

1  2""! 

Extractives                   .       .... 

*•*  1 

4  0 

Soluble  salts     

*-v  I 
6.4  f*    ' 

Insoluble  salts. 

1.7 

THE    BLOOD  541 

Fibrin  is  the  substance  formed  in  the  so-called  spontaneous 
coagulation  of  blood,  lymph,  and  transudates,  or  by  the  addition  of 
serum,  or  of  thrombin,  to  a  solution  of  fibrinogen.  The  typical 
fibrin,  as  obtained  by  whipping  blood  with  a  bundle  of  twigs  or 
broom,  and  washing  until  white,  is  in  elastic  fibers,  insoluble  in 
water,  alcohol,  or  ether.  In  dilute  salt  solution,  putrefaction  being 
prevented,  it  dissolves  very  slowly  at  the  ordinary  temperature,  some- 
what more  rapidly  at  40°.  In  solution  of  HC1,  KHO,  or  NaHO  of 
1  p/m  it  swells,  gelatinizes,  and  slowly  dissolves  after  some  days.  It 
decomposes  hydrogen  peroxid  energetically,  but  not  after  having  been 
heated,  or  in  contact  with  alcohol. 

A  solution  of  pure  fibrinogen  does  not  coagulate  at  the  ordinary 
temperature,  but  it  does  so  very  soon  after  addition  of  a  little  blood- 
serum,  or  of  a  fragment  of  fibrin  washed  with  water  only.  These 
therefore  contain  a  substance,  an  enzym,  called  thrombin,  or  fibrin- 
ferment,  which  sets  up  the  conversion  of  fibrinogen  into  fibrin.  This 
substance  is  by  some  believed  to  be  a  globulin,  by  others  a  nucleo- 
proteid.  It  is  active  in  very  small  amount,  most  active  at  about 
40°  and  in  presence  of  calcium  salts.  It  does  not  act  in  the  absence 
of  neutral  salts,  and  its  power  is  completely  destroyed  by  a  tempera- 
ture of  70°.  The  coagulation  of  blood  is,  however,  a  more  complex 
process  than  the  coagulation  of  fibrinogen  alone,  and  in  it  the  cor- 
puscles play  a  part  (see  below).  The  plasma  is  believed  to  contain, 
not  thrombin,  but  its  zymogen,  prothrombin,  which  is  converted  into 
thrombin  by  the  soluble  calcium  salts. 

Serum-globulin  —  Paraglobulin  —  Fibrinoplastic  substance  — 
occurs  in  the  blood -plasma  and  serum,  and  in  the  red  and  white 
blood -corpuscles,  and  constitutes  more  than  half  of  the  total  proteins 
of  the  blood,  also  in  lymph,  in  transudates  and  exudates,  and  patho- 
logically in  the  urine.  It  is  probably  not  a  simple  substance,  but  a 
mixture  of  two  or  more  globulins.  It  has  the  general  properties  of 
the  globulins.  When  moist  it  forms  white  flocks,  not  elastic  or 
sticky.  It  differs  from  fibrinogen  in  not  being  precipitated  by  an 
equal  volume  of  saturated  sodium  chlorid  solution,  and  only  incom- 
pletely by  salting  with  sodium  chlorid  to  saturation.  It  is  completely 
precipitated  by  salting  with  magnesium  sulfate,  or  by  addition  of  an 
equal  volume  of  saturated  ammonium  sulfate  solution.  Its  coagulation 
temperature  in  solutions  containing  5  to  10%  of  sodium  chlorid  is 
75°.  Its  solutions  are  laevogyrous,  HD=  — 47.8°.  Serum -globulin, 
as  usually  obtained  from  blood,  when  boiled  with  dilute  acids,  yields 
a  reducing  substance.  A  glycoproteid,  or  jecorin,  is  therefore  con- 
tained in  it  or  carried  down  with  it. 

Serum -globulin  is  obtained  from  blood -serum  by  slight  acidula- 
tion  with  acetic  acid,  and  addition  of  from  10  to  20  volumes  of  water, 


542  MANUAL    OF    CHEMISTRY 

when  it  separates  as  a  flocculent  precipitate,  which  is  purified  by 
solution  in  dilute  salt  solution,  and  reprecipitation  by  water.  As 
so  obtained  it  is  not  free  from  lecithins  and  thrombin.  It  can  be 
obtained  free  from  the  latter  from  the  fluid  of  hydrocele. 

Serum-albumin — occurs  in  blood -plasma  and  serum,  in  lymph, 
in  transudates  and  exudates,  probably  in  many  tissues,  and,  patho- 
logically, in  the  urine.  When  moist  it  is  a  white,  flocculent  material; 
when  dry,  translucent,  gummy,  brittle,  and  hygroscopic.  It  has  the 
general  properties  of  the  albumins.  It  is  not  a  simple  substance,  but 
a  mixture  of  three  serines,  of  which  one  is  amorphous  and  two 
crystalline,  one  crystallizing  in  hexagonal  prisms,  the  other  in  long 
needles.  The  mixed  serum -albumin  has  a  coagulation  temperature 
varying  from  70°  to  85°,  depending  upon  the  quantity  of  NaCl 
present,  and  the  reaction.  It  is  Ia3vogyrous,  MD= — 62.6°  to  64.6°. 
It  has  not  been  obtained  entirely  free  from  salts.  From  solutions 
containing  the  minimum  amount  of  salts  it  is  not  coagulated  by  heat 
or  by  alcohol,  but  is  after  addition  of  NaCl. 

Blood-serum. — When  blood  is  drawn  from  the  blood-vessels  it 
soon  coagulates  into  a  jelly-like  mass,  occupying  the  volume  of  the 
original  liquid.  This  mass  soon  contracts  and  expels  a  liquid,  which 
is  the  serum,  and  which  differs  from  the  plasma  in  that  it  contains 
thrombin,  and  has  lost  flbrinogen.  In  other  respects  the  two  are 
qualitatively  alike.  It  is  a  sticky  liquid,  more  strongly  alkaline  than 
the  plasma,  sp.  gr.  1027  to  1032,  pale  yellow,  with  a  greenish  tinge, 
usually  clear,  but  opalescent  or  milky  during  digestion  of  fats. 

The  constituents  of  the  plasma  and  of  the  serum,  other  than 
the  proteins,  being  identical,  are  most  readily  studied  in  the  serum, 
which  is  more  easily  obtainable  than  the  plasma.  They  include  the 
fats,  carbohydrates,  extractives  and  mineral  salts.  The  term  "ex- 
tractives," in  an  analytical  statement,  is  the  equivalent  of  "miscel- 
laneous "  in  a  classification,  and  the  substances  arranged  under  this 
head  are  of  diverse  nature,  present  in  small  quantity,  and,  while  they 
are  not  separately  determined  in  the  particular  analysis  referred  to, 
some  of  them  are  of  great  physiological  interest. 

Fats  —  exist  in  the  plasma  or  serum,  suspended  in  minute  oil 
globules,  as  a  fine  emulsion.  They  are  present  during  fasting  in 
the  proportion  of  1  to  7  p/m,  and  are  greatly  increased  in  amount 
during  digestion  of  fats.  Soaps,  derived  from  the  fats,  are  also 
present.  Besides  the  true  fats  (p.  318),  the  plasma  contains  lecithins 
(p.  319),  cholesterol  and  cholesterol  esters  (p.  529). 

Carbohydrates. —  The  carbohydrates  of  the  blood  appear  to  exist 
almost  exclusively  in  the  plasma,  none  having  been  found  in  the 
corpuscles,  except  glycogen  in  the  leucocytes.  They  consist  of  glu- 
cose, glycogen  (?),  and  a  carbohydrate  in  some  form  of  nitrogenized 


THE    BLOOD  543 

or  phosphorized  combination.  Glucose  is  considered  to  be  a  con- 
stant constituent  of  the  plasma,  even  during  starvation,  and  to  be 
present  in  about  the  proportion  of  1  to  1.5  p/m,  without  any  notable 
variations  in  different  parts  of  the  circulation  under  normal  condi- 
tions, except  that  it  is*  greatly  increased  in  amount  in  the  portal 
blood  during  digestion  of  carbohydrates.  The  analytical  results  in 
this  regard,  however,  require  revision,  in  the  light  of  the  discovery  in 
the  blood  of  a  reducing  substance  other  than  glucose  (see  Jecorin, 
p.  544) .  The  amount  of  reducing  substance  in  the  blood  is  increased 
after  hasmorrhage,  and  in  diabetes.  When  the  proportion  of  sugar 
in  the  blood  exceeds  3  p/m  (hyperglykaemia),  either  from  excessive 
absorption,  or,  in  natural  or  experimental  diabetes,  it  is  eliminated 
by  the  urine  (glycosuria).  It  is  doubtful  whether  the  plasma  con- 
tains glycogen,  which  is  a  constituent  of  tissue  elements  rather  than 
of  fluids  in  the  body.  That  the  plasma  contains  small  quantities  of 
a  substance  which  does  not  reduce  Fehling's  solution,  but  which 
yields  a  reducing  substance  on  boiling  with  dilute  acids,  is  certain, 
but  whether  any  of  this  is  glycogen  or  not  remains  to  be  determined. 
The  whole  of  the  reducing  substance  so  produced  by  acids  is  not 
derived  from  glycogen.  A  part,  and  possibly  all,  is  derived  from  the 
decomposition  of  jecorin,  or  a  jecorin -like  substance,  present  in  the 
plasma.  This  may  also  be  the  origin  of  the  so-called  animal  gum, 
obtained  from  the  serum,  which  yields  a  reducing  substance  by  the 
action  of  boiling  dilute  acids,  is  said  to  have  the  formula  (CeHioOs)*, 
does  not  ferment,  and  is  optically  inactive. 

Enzymes. —  The  plasma  contains  several  enzymes  or  zymogens, 
which  are  probably  produced  by  the  corpuscular  elements:  (1)  Pro- 
thrombin,  the  zymogen  of  thrombin,  the  fibrin -forming  enzym; 
(2)  a  diastatic  enzym.  Blood  serum  or  lymph,  added  to  starch 
paste  or  glycogen  solution,  brings  about  the  formation  of  maltose 
and  isomaltose,  if  the  mixture  be  kept  at  about  40°;  (3)  a  glu- 
case,  or  inverting  enzym,  which  causes  the  inversion  of  the  product 
of  the  diastatic  action,  with  formation  of  glucose,  if  the  action  above 
mentioned  be  allowed  to  continue;  (4)  glycolyse.  The  proportion 
of  glucose  in  blood  serum  gradually  diminishes  on  standing,  even 
in  the  absence  of  all  organized  ferments.  This  glycolysis  is  due  to 
the  action  of  an  enzym  whose  function  is  destroyed  by  a  temperature 
of  54°,  and  which  apparently  originates  from  the  leucocytes;  (5)  a 
lipolytic  enzym,  which  saponifies  neutral  fats.  Besides  the  above, 
the  blood  contains  substances,  probably  enzymes,  existing  in  or  de- 
rived from  the  corpuscular  elements,  which  bring  about  the  conver- 
sion of  the  emulsified  fats  into  some  unknown  form  of  soluble 
combination,  and  which  arrest  the  action  of  the  pepsin,  trypsin  and 
chymosin  absorbed  from  the  intestine. 


544  MANUAL    OF    CHEMISTRY 

Jecorin  —  is  a  substance  obtained  from  the  liver,  spleen,  muscle, 
brain  and  blood,  more  abundantly  from  venous  than  from  arterial, 
and  probably  existing  in  many  cellular  structures,  whose  composition 
is  undetermined,  although  it  is  known  to  contain  sulfur  and  phos- 
phorus. It  is  soluble  in  ether,  but  insoluble  in  alcohol,  which 
precipitates  it  from  its  ethereal  solution.  It  reduces  Fehling's  solu- 
tion, and  glucose  has  been  obtained  from  it  in  the  form  of  its 
osazone.  By  heating  with  alkaline  solutions  and  cooling  it  solidifies 
to  a  jelly. 

The  yellow  coloring  matter  of  the  plasma  and  serum  appears  to 
belong  to  the  class  of  luteins,  or  lipochroms,  which  exist  in  fats, 
corpora  lutea,  egg-yolks,  etc.  A  coloring -matter  has  been  obtained 
from  the  serum  of  ox  blood,  which,  in  amylic  alcohol  solution, 
gives  a  spectrum  of  two  bands,  one  covering  F,  the  other  between 
F  and  G. 

Extractives. —  The  most  abundant  are  urea,  creatin,  and  salts  of 
uric,  carbamic,  paralactic  and  hippuric  acids;  also,  pathologically, 
xanthin  bases,  leucin,  tyrosin  and  biliary  salts  and  pigments.  Urea 
is  present  in  human  blood  in  the  proportion  of  0.14  to  0.4  p/m; 
more  abundant  in  the  blood  of  the  splenic,  portal  and  hepatic  veins 
than  in  that  of  the  carotid  artery;  more  abundant  in  placental 
blood,  0.28  to  0.62  p/m.  In  animals  the  proportion  rapidly  increases 
after  nephrectomy,  reaching  2.06  to  2.76  p/rn  in  27  hours.  In 
human  blood  the  amount  is  greatly  increased  in  cholera,  2.4  to  3.6 
p/m,  and,  particularly,  in  nephritis,  15.0  p/m. 

Mineral  Salts. — The  serum  contains  a  somewhat  smaller  quantity 
of  mineral  material  than  the  plasma,  a  part  of  the  calcium  salts 
having  passed  into  the  clot.  The  total  ash  of  the  serum  equals  8.3 
to  9.2  p/m.  In  composition  it  does  not  vary  greatly  in  different 
animals.  In  1000  parts  of  human  blood  serum  there  are:  K2O-0.387 
to  0.401,  Na2O-i.290,  CaO-0.155,  MgO-0.101,  Cl-3.565  to  3.659, 
besides  phosphoric  acid,  and  traces  of  silicon,  fluorin,  iron,  man- 
ganese, copper  and  ammoniacal  compounds.  The  most  abundant 
constituent  of  the  ash  is  sodium  chlorid,  60  to  70  per  cent,  of  the 
ash.  The  calcium  and  magnesium  are  probably  present  as  phos- 
phates, and  the  former  also  as  chlorid,  the  sodium  and  potassium  as 
chlorids,  phosphates  and  carbonates  or  bicarbonates.  The  amount  of 
base  present  is  in  excess  of  the  amount  of  acid,  therefore  a  part  of 
the  bases  must  be  present  as  carbonates  or  in  organic  combination. 
The  presence  of  carbonates  is  demonstrated.  The  organic  acids  above 
mentioned  are  contained  in  the  plasma  in  saline  combination;  and 
the  existence  of  mineral  elements  in  protein  combination  is  shown 
by  the  fact  that  the  mineral  constituents  are  not  completely 
removable  by  dialysis. 


THE    BLOOD  545 


BLOOD   CORPUSCLES. 

The  corpuscular  elements  of  the  blood  are  of  three  kinds:  the 
red  corpuscles,  the  white  corpuscles,  or  leucocytes,  and  the 
plaques,  or  platelets. 

The  red  corpuscles  are  separated  from  the  plasma  by  the 
methods  given  above.  As  they  are  heavier,  they  sink  more  rapidly 
than  the  other  corpuscular  elements,  and  are  consequently  found  in 
the  lower  part  of  the  deposit.  Their  variations  in  size,  shape  and 
number  have  been  the  subject  of  much  careful  study.  Suffice  it  to 
say  here  that  in  man  they  are  rounded  bi- concave  discs,  non- 
neucleated,  having  an  average  diameter  of  7  to  8  /*  (/A=micro-milli- 
meter=0.001  mm.),  and  existing  in  the  blood  in  the  average  number 
of  4  to  5  millions  in  1  cubic  millimeter.  In  other  mammals,  except 
camels,  they  have  the  same  shape  as  in  man,  but  differ  in  size,  while 
in  camels,  birds,  fishes  and  reptiles,  they  are  oval  and  neucleated. 

Composition. — Analyses  of  human  blood  corpuscles  show  them 
to  contain  681.63  to  687.86  p/m  of  water,  and  318.37  to  312.14  of 
solids.  The  corpuscles  of  animals  contain  a  larger  proportion  of 
solids:  pig— 374.38  p/m,  ox— 408.14,  horse— 386.82,  dog— 372.85.  In 
the  solids  the  proportion  of  organic  constituents  to  mineral  salts  is 
much  greater  in  the  corpuscles  than  in  the  plasma.  The  318.37  and 
312.14  p/m  of  solids  in  the  above  analyses  contain  respectively  311.1 
and  303.17  of  organic  constituents  and  7.36  and  8.97  of  mineral. 
The  solids  consist  of  a  proteid  coloring  matter,  containing  iron, 
haemoglobin;  albumens,  including  a  nucleoalbumen  and  a  globulin; 
lecithins,  cholesterol,  fatty  acids,  and  salts. 

On  contact  with  water,  by  alternate  freezing  and  thawing,  by 
agitation  with  ether  or  with  chloroform,  or  by  the  action  of  bile,  the 
corpuscles  swell  and  give  up  their  coloring  matter,  which  goes  into 
solution,  leaving  the  stroma,  a  colorless  mass,  which  may  be  made 
to  retract  to  the  original  size  and  shape  of  the  corpuscle  by  the 
action  of  carbon  dioxid,  dilute  acids,  acid  salts  and  other  agents. 
This  liberation  of  the  pigment  is  referred  to  as  "lakeing,"  or  "lake 
coloring"  (lakfarben),  from  the  resemblance  of  the  product  to  the 
pigments  called  lakes. 

Blood  Coloring  Substances. — The  red  color  of  the  blood  depends 
upon  the  presence  in  the  red  corpuscles  of  a  coloring  matter,  haemo- 
globin, which  exists  in  the  two  forms  of  haemoglobin  and  oxy- 
haemoglobin.  In  what  condition  this  pigment  exists  in  the  cor- 
puscles is  not  clearly  established.  That  it  exists  in  some  form  of 
combination  may  be  inferred  from  the  facts  that  in  the  corpuscles  it 
is  insoluble  in  water,  while  free  haemoglobin,  that  of  many  animals 
at  all  events,  is  readily  soluble;  that  hemoglobin  is  crystalline,  while 
35 


546  MANUAL    OF    CHEMISTRY 

no  crystalline  structure  can  be  made  out  in  the  corpuscles;  that  the 
oxy- compound  in  the  corpuscles  gives  off  its  oxygen  in  a  vacuum 
more  readily  than  ordinary  oxyha3moglobin  does;  that  the  pigment 
in  the  corpuscles  decomposes  hydrogen  peroxid  without  itself  suffer- 
ing oxidation,  which  is  not  the  case  with  haemoglobin;  and  that  the 
native  substance  is  more  resistant  to  the  action  of  reagents  than  free 
hemoglobin.  It  certainly  exists  in  the  corpuscles  in  two  forms  of 
oxidation,  one  yielding  hemoglobin,  and  largely  predominating  in 
the  blood  in  asphyxia,  the  other  yielding  oxyhemoglobin,  and 
largely  predominating  in  arterial  blood;  the  proportion  of  the  two  in 
venous  blood  being  intermediate  between  the  above.  To  the  former 
of  these  combinations  the  name  phlebin  has  been  given,  to  the  latter 
the  name  arterin. 

Haemoglobin  —  Reduced  Haemoglobin  —  exists  in  very  small 
amount  in  arterial  blood,  and  almost  exclusively  in  the  blood  after 
death  from  asphyxia.  It  is  more  soluble  and  more  difficultly  crystal- 
lizable  than  oxyhaemoglobin,  but  isomorphous  with  it,  although  the 
crystals  are  darker  in  color.  Its  aqueous  solution  is  purple,  and  gives  a 
spectrum  of  a  single  broad  band,  covering  D,  and  about  three-fourths 
of  the  space  between  D  and  E.  The  violet  end  of  the  spectrum  is 
less  absorbed  than  with  oxyhemoglobin  solutions  of  corresponding 
concentration  (No.  1,  Fig.  37,  p.  547).  It  absorbs  oxygen  rapidly 
from  air,  with  formation  of  oxyhemoglobin.  Hemoglobin  is  ob- 
tained from  oxyhemoglobin  by  bringing  its  solution  into  a  vacuum, 
by  passing  indifferent  gases  through  it,  or  by  the  action  of  reducing 
agents,  such  as  Stokes'  reducing  reagent,  consisting  of  an  ammoniacal 
solution  of  ferrous  tartrate. 

Oxyhaemoglobin — is  the  form  in  which  the  blood -coloring  matter 
is  usually  obtained.  The  haemoglobins  from  the  blood  of  different 
animals  differ  from  each  other  in  several  particulars ;  in  crystalline 
form,  in  solubility,  and  in  chemical  composition.  The  most  usual 
crystalline  form,  including  that  of  human  hemoglobin,  is  in  rhombic 
prisms  or  needles,  but  hemoglobin  from  guinea  pig's  blood  crystal- 
lizes in  rhombic  octahedra,  and  that  from  the  squirrel  in  hexagonal 
plates.  They  differ  also  in  the  facility  with  which  the  crystals  are 
formed,  which  is  inversely  as  their  solubilities.  The  hemoglobin  of 
the  blood  of  the  horse  and  guinea-pig  are  sparingly  soluble  and  crys- 
tallize easily,  those  of  human  blood,  ox  blood  and  pig's  blood  are 
very  soluble,  and  crystallize  with  difficulty.  The  crystals  of  oxyhemo- 
globin  are  bright -red  in  color,  and  are  doubly  refracting.  They  con- 
tain from  3  to  10%  of  water  of  crystallization.  In  some  hemoglobins 
there  are  two  atoms  of  sulfur  to  each  atom  of  iron,  in  others  there 
are  three.  The  hemoglobins  of  most  animals  contain  carbon,  hy- 
drogen, nitrogen,  iron,  sulfur,  and  oxygen;  but  those  of  certain  birds 


THE    BLOOD 


547 


40 


8. 


9. 


ao. 


PIG.  37.  Spectra  of  :  (1)  Reduced  haemoglobin;  (2)  Oxyhaemoglobin,  concentrated;  (3)  Same, 
dilute;  (4)  Same,  very  dilute;  (5)  Metheemoglobin,  in  faintly  alkaline  solution;  (6)  Carbon  mon- 
oxid  haemoglobin;  (7)  Hsemochromogen,  in  alkaline  solution;  (8)  Heematin,  in  acid  solution; 
(9)  Hsematin,  in  alkaline  solution;  (10)  Haematoporphyrin,  in  acid  solution, 


548  MANUAL    OF    CHEMISTRY 

also  contain  phosphorus,  probably  in  the  form  of  a  nucleic  acid. 
The  molecular  weight  of  haemoglobin  is  certainly  very  large;  a  for- 
mula for  that  from  dog's  blood  has  been  given  as  CeseH^sNieiFeSa- 
Oisi,  corresponding  to  a  molecular  weight  of  14,129;  which  must, 
however,  be  accepted  with  some  reserve.  Oxyhaemoglobin  is  more 
readily  soluble  in  dilute  acids  and  alkalies  than  in  pure  water,  insol- 
uble in  alcohol,  ether,  chloroform,  benzene,  or  carbon  disulfid. 
When  dried  in  vacuo  at  the  ordinary  temperature,  it  may  be  heated 
to  115°  without  suffering  decomposition. 

When  haemoglobin  from  the  blood  of  the  ox  absorbs  oxygen  to 
form  oxyhaemoglobin,  it  does  so  in  the  proportion  of  1.34  cc.  of 
oxygen  for  each  gram  of  haemoglobin  (at  0°  and  760  mm.),  which, 
calculated  for  weight,  is  equal  to  five  atoms  of  oxygen  for  three 
molecules  of  hemoglobin.  The  combination  is  a  "loose  "one,  in 
that  the  combined  gas  is  readily  given  off  in  a  vacuum,  or  by  passage 
of  an  indifferent  gas  through  the  solution.  Haemoglobins,  when 
heated  in  solution  to  60°  to  70°,  or  when  acted  upon  by  acids,  alka- 
lies, or  certain  metallic  salts,  are  decomposed  into  a  protein  and  a 
colored  derivative  containing  iron.  The  protein,  called  globin,  is 
probably  a  globulin,  insoluble  in  water,  but  very  soluble  in  dilute 
acids  or  alkalies,  insoluble  in  ammonia  in  presence  of  ammonium 
chlorid.  It  is  coagulated  by  heat,  but  the  coagulum  is  soluble  in 
acids.  Nitric  acid  precipitates  it  in  the  cold,  but  not  from  warm 
solutions.  The  ferruginous  pigment  resulting  from  the  decompo- 
sition differs  according  to  the  degree  of  oxidation  of  the  haemoglobin. 
If  oxygen  be  excluded,  the  product  is  haemochromogen,  but  in 
presence  of  oxygen  haematin  (p.  550)  is  formed. 

The  spectrum  of  oxyhaemoglobin  varies  with  the  degree  of  con- 
centration of  the  solution.  When  a  solution,  sufficiently  concentrated 
to  be  opaque  when  observed  spectroscopically  in  a  layer  of  a  given 
thickness,  is  gradually  diluted  it  first  allows  portions  of  the  red  and 
orange  to  pass.  On  further  dilution,  light  appears  in  the  green, 
leaving  a  single  broad  band  extending  from  about  midway  between 
C  and  D  to  beyond  b  (No.  2,  Fig.  37).  On  still  further  dilution  this 
band  divides  into  two,  giving  the  characteristic  oxyhaemoglobin  spec- 
trum, consisting  of  two  bands,  one  (a)  between  D  and  E,  and  resting 
on  D,  the  other  (ft)  extending  from  about  midway  between  D  and  b 
to  b.  The  band  a  is  narrower,  darker  and  more  sharply  defined  than 
ft  (No.  3,  Fig.  37).  This  spectrum  is  still  visible  with  a  solution  of 
0.1  p/m  in  a  layer  1  cm.  thick.  With  further  dilution  the  band  ft 
disappears  first  (No.  4,  Fig.  37).  On  addition  of  reducing  agents  the 
spectrum  changes  to  that  of  haemoglobin  (No.  1,  Fig.  37). 

Pseudohaemoglobin. — When  a  solution  of  oxyhaemoglobin  is 
reduced  by  ammonium  sulfid  until  it  gives  the  spectrum  of  haemo- 


THE    BLOOD  549 

globin,  it  will  still  give  off  oxygen  in  the  vacuum.  In  this  condition 
it  is,  therefore,  not  completely  reduced,  and  the  intermediate  form 
of  oxidation  which  is  supposed  to  exist  in  the  solution  has  been 
called  pseudohaemoglobin. 

Methaemoglobin  —  is  a  product  of  oxidation  of  haemoglobin, 
containing  the  same  proportion  of  oxygen  as  oxyhaemoglobin,  but 
in  state  of  firmer  chemical  union,  which  may  be  expressed  by  writing 

/° 
the  formula  of   oxyhaemoglobin  as  Hb\  I  ,  and  that  of  methaemo- 

globin  as  Hb^Q.     Methaemoglobin  occurs  in  transudates  and  exu- 

dates,  and  in  the  urine  in  haematuria  and  haemoglobinuria,  and, 
particularly,  in  poisoning  by  poisons  such  as  potassium  chlorate, 
amyl  nitrite  and  the  alkaline  nitrites.  It  is  formed  from  haemo- 
globins when  blood  is  kept  in  hermetically  sealed  vessels,  or  by  the 
action  upon  them  of  many  oxidizing  agents,  ozone,  permanganates, 
chlorates,  nitrites,  etc.  It  crystallizes  in  red-brown,  hexagonal 
prisms,  needles  or  plates,  which  form  a  brown-red  solution  with 
water,  which  changes  to  bright -red  with  alkalies.  It  is  very  soluble 
in  water.  Its  neutral,  or  faintly  alkaline  or  acid,  solutions  give  a 
spectrum  of  a  single  band  between  C  and  D,  nearer  to  C  and  united 
by  a  space  of  partial  absorption  with  the  <*  band  of  the  oxyhaemo- 
globin spectrum,  which  is  also  present  (No.  5,  Fig.  37).  By  the 
action  of  reducing  agents  upon  faintly  alkaline  solutions  the  spec- 
trum changes  to  that  of  reduced  haemoglobin. 

Carbon  Monoxid  Haemoglobin  —  is  a  form  of  combination  of 
haemoglobin  existing  in  the  blood  of  those  poisoned  by  carbon  mon- 
oxid,  or  by  illuminating  gas,  and  whose  production  is  the  cause  of 
death  by  that  poison.  It  is  a  definite  compound,  containing  one 
molecule  of  CO  for  each  molecule  of  haemoglobin,  and,  being  more 
stable  than  oxyhaemoglobin,  is  not  oxidized  in  the  lungs,  and  thus 
destroys  the  oxygen -carrying  function  of  the  blood  coloring -matter. 
It  is  formed  by  passing  CO  through  blood,  or  through  a  solution 
of  haemoglobin  or  of  oxyhaemoglobin.  It  crystallizes  readily  in 
forms  isomorphous  with  oxyhaamoglobin ,  but  more  bluish  in  color, 
more  stable,  and  less  soluble.  Its  solutions  are  bright -red  in  color 
and  give  a  spectrum  of  two  bands,  resembling  that  of  oxyhaemo- 
globin, but  differing  therefrom  in  that  the  two  bands  are  of  equal 
intensity,  are  somewhat  differently  placed  (No.  6,  Fig.  37),  and 
also  in  that  reducing  agents  do  not  change  the  spectrum  to  that 
of  reduced  haemoglobin.  Carbon  inonoxid  blood,  when  mixed  with 
an  equal  volume  of  NaHO  solution  (sp.  gr.  1.3)  forms  a  b  right - 
red  mass,  while  normal  blood,  similarly  treated,  forms  a  dirty-brown 
mass  with  a  greenish  tinge. 


550  MANUAL    OP    CHEMISTRY 

Carbon  Dioxid  Haemoglobin. — A  solution  of  haemoglobin  shaken 
with  a  mixture  of  oxygen  and  carbon  dioxid  takes  up  both  gases, 
forming  molecular  combinations  with  each.  It  is  supposed  that 
the  carbon  dioxid  combines  with  the  protein  factor  of  the  coloring 
matter.  Carbon  dioxid  alone  is  also  absorbed  by  hemoglobin  solu- 
tions, and  the  spectrum  is  then  that  of  reduced  haemoglobin,  while 
a  part  of  the  coloring  matter  is  decomposed  with  separation  of  globin. 

Haemochromogen  —  is  formed  by  the  action  of  NaHO  upon 
haemoglobin  in  complete  absence  of  oxygen,  or  by  the  action  of 
reducing  agents  upon  haematin  in  alkaline  solution.  It  gives  a 
spectrum  of  two  bands,  resembling  the  oxyhaemoglobin  bands  in 
relative  intensity,  but  placed  nearer  to  the  violet  end  of  the  spectrum 
(No.  7,  Fig.  37). 

Haematin  —  is  produced  by  decomposition  of  oxyhaemoglobin  by 
alkalies.  It  exists  in  old  transudates,  is  formed  by  the  action  of 
the  gastric  and  pancreatic  secretions  upon  haemoglobin,  and  is  met 
with  in  the  urine  in  poisoning  by  hydrogen  arsenid.  It  is  amor- 
phous, blue -black,  insoluble  in  water,  dilute  acids,  alcohol,  ether,  or 
chloroform,  sparingly  soluble  in  hot  glacial  acetic  acid,  soluble  in 
acidulated  alcohol  or  ether,  very  soluble  in  dilute  alkalies.  Its  al- 
kaline solutions  are  dichroic,  red  by  reflected  light,  green  by  trans- 
mitted; its  acid  solutions  are  brown.  The  formula  usually  ascribed 
to  it  is  C32H32N4FeO4.  In  acid  solution  in  alcohol  or  ether  it  gives 
a  spectrum  of  four  bands  (No.  8,  Fig.  37) :  a?  the  darkest,  near  to  C, 
and  extending  about  one -third  to  D;  ft  resting  on  D,  narrower  and 
paler  than  a;  y  between  D  and  E,  nearer  to  E,  broader  and  paler 
than  a;  8  the  broadest  of  the  four,  a  pale  band  whose  center  is 
midway  between  b  and  F,  and  covering  about  three-quarters  of  the 
space.  The  interval  between  y  and  8  is  partly  absorbed.  In  al- 
kaline solution  haematin  gives  a  spectrum  of  a  single  band,  extending 
from  near  C  to  beyond  D  (No.  9,  Fig.  37). 

Haemin — is  a  compound  of  haematin  with  chlorin  or  iodin,  whose 
formation  is  utilized  as  the  most  characteristic  test  for  blood.  It 
forms  red-brown  crystals,  which,  when  perfect,  are  rhombic  prisms, 
insoluble  in  water,  alcohol,  ether,  dilute  acids  or  chloroform,  soluble 
without  decomposition  in  hot  glacial  acetic  acid,  soluble  with  decom- 
position in  acidulated  alcohol  or  in  dilute  NaHO  solution.  The 
crystals,  known  also  as  Teichmann's  crystals,  are  best  obtained  as 
follows:  a  fragment  of  the  dried  stain  is  placed  upon  a  glass  slide, 
upon  which  a  very  minute  drop  of  dilute  sodium  chlorid,  or  iodid, 
solution  has  been  previously  evaporated,  and  covered  with  a  cover- 
glass.  Glacial  acetic  acid  is  then  run  in  beneath  the  cover,  and  the 
slide  cautiously  heated  over  a  very  small  flame  until  bubbles  just 
begin  to  appear,  when  the  slide  is  raised  about  three  inches  above 


THE    BLOOD  551 

lame  and  kept  warm  for  a  few  minutes,  while  the  loss  of  acid  by 
evaporation  is  supplied  by  fresh  glacial  acetic  acid  placed  at  the  edge 
of  the  cover  with  a  slender  glass  rod.  The  slide  is  now  allowed  to 
cool,  and,  during  cooling  and  evaporation  of  the  acid,  examined  with 
a  one -fifth  inch  objective.  The  crystals  are  usually  found  near  the 
edge  of  the  cover,  or  imprisoned  in  the  remains  of  the  clot,  and  are 
generally  all  in  a  small  space,  while  the  remainder  of  the  preparation 
is  free  from  them.  The  acid  must  not  be  allowed  to  boil,  or  the 
crystals  may  be  mechanically  carried  out  from  under  the  cover.  The 
formation  of  the  crystals  under  these  conditions  may  be  accepted  as 
certain  evidence  of  the  presence  of  blood -pigment,  but  their  non- 
formation  is  not  evidence  of  its  absence.  They  cannot  be  obtained 
if  the  stain  contains  iron -rust,  or  has  been  treated  with  chlorin  or 
with  certain  kinds  of  soap. 

Haematoporphyrin  —  is  an  isomere  of  bilirubin  (pp.  528,  531), 
therefore  containing  no  iron,  CieHig^Os,  and  is  derived  from  ha3- 
matin:  C32H32N4FeO4+2H2O==2Ci6Hi8N203H-Fe.  It  occurs  normally 
in  urine  in  minute  quantity,  and  is  notably  increased  in  poisoning 
by  sulfonal.  It  forms  a  compound  with  HC1  which  crystallizes  in 
long,  red -brown  needles,  and  is  precipitated  from  its  HC1  solution 
by  partial  neutralization  and  addition  of  sodium  acetate,  as  an  amor- 
phous, brown  powder.  It  is  soluble  in  dilute  acids  or  alkalies,  the 
acid  solutions  having  a  purple  color,  and  the  alkaline  solutions  being 
red.  Reducing  agents  convert  it  into  urobilin,  and  when  injected 
into  the  circulation  of  rabbits  it  is  partly  eliminated  in  that  form. 
In  acid  solution  it  gives  a  spectrum  of  two  bands  (No.  10,  Fig.  37), 
/?,  the  narrower  and  less  intense,  between  C  and  D,  nearer  to  D;  and 
«,  much  darker  and  broader,  about  midway  between  D  and  E,  with  a 
space  of  less  complete  absorption  extending  nearly  to  D.  In  alkaline 
solution  it  gives  a  four-band  spectrum,  one  (a)  between  C  and  D,  a 
broader  one  (/3)  over  D,  a  third  (y)  between  D  and  E,  extending 
nearly  to  E,  and  a  fourth  (8)  between  b  and  F.  On  addition  of 
alkaline  zinc  chlorid  solution  the  bands  a  and  8  gradually  fade  out, 
leaving  ft  and  y. 

Hsematoidin  —  another  decomposition -product  of  hemoglobin,  is 
identical  with  bilirubin  (p.  528). 

The  stroma  (p.  545)  of  the  red  corpuscles  contain  the  constit- 
uents other  than  the  coloring  matter,  and  probably  a  portion  of  the 
salts.  The  principal  organic  constituents  are:  a  globulin,  which  has 
been  called  cell -globulin,  and  a  nucleoalbumen.  The  non- nucleated 
corpuscles  of  the  mammalia  contain  no  nucleoproteid,  although  the 
nucleated  corpuscles  of  the  birds  and  fishes  contain  a  nuclein  and  a 
nucleoproteid,  which  forms  a  mucilaginous  solution  with  a  10  per 
cent.  NaCl  solution.  The  proportion  of  albumens  to  haemoglobin  is 


552  MANUAL    OF    CHEMISTRY 

much  greater  in  nucleated  than  in  non- nucleated  corpuscles.  Thus 
human  corpuscles  contain  in  1000  parts  868  to  943  of  haemoglobin 
against  122  to  51  parts  of  albumens,  while  in  serpents7  blood  the 
proportion  is  467  haemoglobin  to  525  of  albumens.  The  red  cor- 
puscles of  frogs '  blood  also  appear  to  contain  fibrinogen,  or  a  related 
protein.  Lecithins  exist  in  human  corpuscles,  in  the  proportion  of 
3.5  to  7.2  p/m,  and  cholesterol  to  the  amount  of  about  2.5  p/m.  The 
total  ash  of  human  corpuscles,  including  the  iron  derived  from  the 
haemoglobin  and  the  phosphoric  acid  derived  from  the  lecithins,  con- 
stitute 3.5  to  3.7  p/m  of  their  weight.  The  salts  vary  in  different 
animals.  In  the  corpuscles  of  the  pig,  ox,  horse  and  dog  the  sodium 
compounds  are  notably  more  abundant  than  those  of  potassium ,  while 
human  corpuscles  contain  sodium  compounds  equivalent  to  0.24  to 
0.65  Na2O,  and  potassium  compounds  equivalent  to  1.41  to  1.59  K2O. 
The  mineral  salts  present  are  potassium  and  sodium  chlorids  and 
phosphates,  with  mere  traces  of  magnesium  salts.  Calcium  com- 
pounds, so  important  in  the  serum,  are  entirely  absent  from  the 
corpuscles. 

The  leucocytes,  or  white  corpuscles,  are  rounded,  colorless  pro- 
toplasmic masses,  endowed  with  the  power  of  amoeboid  movement, 
having  no  limiting  membrane,  which,  on  addition  of  water  or  of  1% 
acetic  acid,  are  seen  to  have  from  one  to  four  nuclei,  round  or 
irregular  in  outline.  They  are  less  numerous  than  the  red  corpus- 
cles, the  average  proportion  between  the  two  being  from  1:350  to 
1:500;  but  their  number  varies  greatly  under  varying  normal,  as 
well  as  pathological,  conditions.  Histologically  they  are  divided  into 
several  groups,  the  members  of  which  differ  from  each  other  in  size, 
in  appearance,  and  in  their  behavior  towards  staining  agents.  Al- 
though no  differences  in  chemical  composition  between  these  several 
kinds  of  white  corpuscles  are 'known  to  exist,  the  differences  in  their 
behavior  towards  stains,  which  are  in  reality  chemical  reagents, 
render  it  highly  probable  that  they  are  not  chemically  identical. 
Indeed  our  knowledge  of  the  chemical  composition  of  the  leucocytes 
is  fragmentary.  The  constituents  of  the  protoplasm  differ  from  those 
of  the  nuclei.  The  bulk  of  the  protoplasm  consists  of  proteins, 
among  which  are  a  substance,  probably  a  nucleoproteid,  nucleohis- 
ton,  soluble  in  water  and  precipitated  by  acetic  acid;  another  nucleo- 
proteid which  swells  to  a  mucilaginous  mass  on  contact  with  alkalies 
or  salt  solution,  and  is  very  similar  to,  if  not  identical  with,  the 
hyaline  substance  of  Rovida,  which  exists  in  pus  cells;  and  a 
globulin,  supposed  to  be  serum -globulin.  Among  these  proteins  is 
the  zymogen  of  thrombin,  which  probably  is  one  of  the  nucleopro- 
teids.  Glycogen  and  fat  are  also  present  in  small  amount.  A 
phosphorized  and  nitrogenized  body  has  also  been  obtained  from  the 


THE  BLOOD  553 

leucocytes,  and  probably  exists  in  their  protoplasm,  which  is  one 
of  the  protagons,  important  constituents  of  nerve  and  brain  tissues, 
which,  on  boiling  with  baryta  water,  are  decomposed  into  cerebrins, 
nitrogenized  but  non-phosphorized  bodies,  and  the  constituents  of 
the  lecithins:  fatty  acids,  glycerophosphoric  acid  and  cholin. 

The  nuclei  of  the  leucocytes  are  rich  in  nucleoproteids,  and  also 
contain  nucleins  and  nucleic  acids. 

But  little  is  known  of  the  chemical  composition  of  the  plaques 
beyond  the  probability  that  they  consist  largely  of  a  combination  of 
albumen  and  nuclein. 


THE    BLOOD    AS    A   WHOLE. 

The  color  of  the  blood  is  bright -red  if  arterial,  bluish -red  if 
venous,  bright  cherry-red  in  poisoning  by  carbon  monoxid,  brownish- 
red  in  poisoning  by  potassium  chlorate,  anilin,  or  nitro- benzene, 
dark  purple -red  after  death  from  asphyxia.  It  is  opaque,  even  in 
thin  layers.  It  is  salty  in  taste;  and  its  odor  is  similar  to  that  of 
the  animal,  being  more  pronounced  after  addition  of  H2S04;  sp.  gr. 
1,045  to  1,075;  reaction  alkaline.  The  alkalinity  of  the  blood  de- 
pends in  part  upon  the  presence  of  alkaline  bicarbonates  (p.  565) 
and  phosphates,  and  in  part  upon  alkaline  protein  compounds.  The 
normal  degree  of  alkalinity  of  human  blood  has  been  given  by  dif- 
ferent observers  as  equal  to  from  3.38  to  5.95  p/m  of  sodium  car- 
bonate, or  2.55  to  4.5  p/m  of  sodium  hydroxid.  Usually  the  limits 
of  normal  variation  are  placed  at  3.3  to  5.3  p/m  Na2CO3,  or  2.5  to 
4.0  p/m  NaHO.  The  alkalinity  of  the  blood  rapidly  diminishes  after 
its  removal  from  the  circulation,  by  reason  of  the  generation  of  acids, 
which  has  led  to  results  lower  than  the  above,  some  authors  giving 
the  normal  limits  as  low  as  1.8  to  3.0  p/m  NaHO.  Normally  the 
degree  of  alkalinity  is  greater  in  men  than  in  women  and  children; 
and  is  diminished  after  violent  muscular  activity.  It  increases  with 
activity  of  the  stomach  digestion,  and  subsequently  diminishes  from 
absorption  of  hydrochloric  acid  and  peptones  from  the  intestine. 
Pathologically,  it  is  diminished  in  anaemia,  leukaemia,  uraemia,  dia- 
betes, hepatic  diseases,  high  fevers,  and  in  acidism  due  to  adminis- 
tration of  mineral  acids  or  to  the  generation  of  organic  acids  in  the 
body.  It  is  increased  by  administration  of  alkalies,  by  cold  baths, 
and  in  phthisis,  erysipelas,  and  septicaemia  (p.  555). 

The  change  of  coagulation,  which  the  blood  undergoes  shortly 
after  being  drawn  from  the  blood-vessels,  is  a  chemical  phenomenon 
dependent  upon  physical  conditions,  the  precise  nature  of  which  has 
not  been  satisfactorily  explained.  Coagulation  takes  place  with  dif- 


554  MANUAL    OP    CHEMISTRY 

ferent  degrees  of  rapidity  in  the  blood  of  different  animals,  and  with 
different  individuals  of  the  same  race.  In  human  blood  it  usually 
begins  in  2-3  minutes  after  the  blood  is  drawn,  and  it  results  in 
the  formation  of  a  jelly-like  mass  in  7-8  minutes.  If  it  take  place 
rapidly  the  clot  is  uniform  in  appearance,  but  if  it  be  delayed  the 
corpuscles  sink,  the  red  more  rapidly  than  the  white,  and  the  upper 
part  of  the  clot,  the  "buffy  coat"  or  "crusta  phlogistica,"  is  pale  in 
color,  and  contains  few  red  corpuscles  and  many  white  ones.  Coag- 
ulation is  delayed  by  cold,  diminished  oxygen -content,  increased 
carbon  dioxid,  the  presence  of  acids,  alkalies,  ammoniacal  salts, 
oxalates,  fluorids,  egg-albumin,  sugar,  dextrin,  glycerol,  albumoses, 
snake -poison,  toxalbumins,  or  an  infusion  of  the  mouth  of  the  leech, 
or  by  collection  in  oil.  It  is  accelerated  by  warmth,  contact  with 
air,  whipping,  contact  with  solids  to  which  it  adheres,  or  addition  of 
leucocytes,  nucleoproteids,  or  extracts  of  lymphatic  glands,  testicles, 
or  thymus. 

As  to  the  cause  of  coagulation,  and  particularly,  its  non- coagula- 
tion in  the  vessels  during  life,  opinions  differ.  The  following  facts, 
in  addition  to  others  already  discussed,  bear  upon  the  question:  (1) 
the  blood  does  not  coagulate  while  in  contact  with  living,  healthy 
blood-vessels;  (2)  it  remains  fluid  in  a  ligated  section  of  a  vein, 
removed  from  the  body;  (3)  it  coagulates  rapidly  when  collected  in 
a  vacuum  over  mercury;  (4)  it  does  not  coagulate  when  collected 
through  an  oiled  or  vaselined  canula  into  a  similarly  prepared  vessel ; 
(5)  in  such  vessels  it  does  not  coagulate  when  stirred  with  an  oiled 
or  vaselined  glass  rod;  but,  (6)  it  does  coagulate  when  stirred  with 
an  unoiled  rod  ;  (7)  under  the  conditions  of  5  and  6,  coagulation 
begins  when  a  film  of  solid  forms  upon  the  surface  by  drying,  or  if  a 
small  quantity  of  dust  be  present  in  the  oil  or  vaseline;  (8)  it  coagu- 
lates in  living  blood-vessels  when  their  internal  surfaces  become 
roughened,  or  in  presence  of  foreign  material  with  rough  surfaces. 
From  these  facts  it  may  be  inferred  that  the  change  does  not  depend 
upon  the  presence  of  air,  but  that  it  does  depend  in  some  way  upon 
the  physical  condition  of  adhesion.  It  is  generally  admitted,  also, 
that  the  corpuscles,  particularly  the  leucocytes  and  plaques,  contain  a 
zyraogen,  prothrombin,  from  which  an  enzyrn,  thrombin,  is  derived 
in  the  presence  of  calcium  salts,  and  that  thrombin  in  some  unknown 
way,  possibly  by  hydrolytic  splitting,  produces  fibrin  from  fibrin- 
ogen.  It  is  known  that  during  coagulation  notable  destruction  of 
leucocytes  and  of  plaques  occurs,  and  it  is  believed  that  this  break- 
ing down  is  attended  by  a  chemical  action  between  the  nucleoproteid, 
prothrombin  (nucleohiston  ?),  and  the  calcium  compounds,  with 
formation  of  thrombin;  and  that  coagulation  does  not  occur  in  the 
healthy  vessels,  because  this  disintegration  of  corpuscular  elements 


THE   BLOOD  555 

only  takes  place  to  a  limited  extent,  and  the  small  amount  of  throm- 
bin  so  produced  is  destroyed,  probably  by  an  action  of  the  liver. 


CHEMICAL    EXAMINATION    OP    BLOOD. 

The  more  accurate  methods  of  blood  analysis,  including  those  for 
the  examination  of  the  blood -gases,  which  are  used  in  scientific  in- 
vestigation, are  quite  intricate,  and  demand  close  observance  of 
details  and  considerable  manipulative  skill.  As  their  description 
would  require  much  space,  and  as  they  are  not  used  for  clinical  pur- 
poses, the  student  is  referred  to  more  comprehensive  treatises  for  an 
account  of  them.  While  the  methods  of  microscopical  examination 
of  the  blood  for  clinical  purposes  have  been  greatly  perfected,  and 
have  led  to  valuable  results,  there  is  practically  nothing  worthy  of 
consideration  in  the  way  of  chemical  methods  for  this  use.  We  have 
accurate  methods  for  determining  the  physical  quality  of  specific 
gravity,  methods  of  determining  the  reaction,  which  leave  much  to 
be  desired,  and  methods  of  determining  the  quantity  of  haemoglobin, 
some  of  which  are  accurate  but  difficult,  others  more  easily  conducted, 
but  affected  with  large  factors  of  possible  error. 

Specific  Gravity. —  (1)  Htimmerschlag' s  method,  which  depends 
upon  the  fact  that  a  drop  of  an  immiscible  liquid  will  remain  sus- 
pended in  a  liquid  whose  sp.  gr.  is  equal  to  its  own.  A  mixture  is 
made  of  chloroform,  sp.  gr.  =1.526  and  benzene,  sp.  gr.  =0.889,  in 
such  proportions  that  the  sp.  gr.  of  the  mixture  is  about  1.050  to 
1.055,  and  a  drop  of  the  blood  is  allowed  to  fall  into  it.  If  the 
blood-drop  sink  more  benzene  is  added,  if  it  float,  more  chloroform, 
until  the  blood -drop  remains  suspended.  The  sp.  gr.  of  the  mixture 
is  then  determined,  and  is  equal  to  the  sp.  gr.  of  the  blood. 

(2)  By  direct  weighing. — Capillary  tubes  are  used,  drawn  out  at 
the  ends,  which  are  about  12  cm.  long,  and  have  internal  diameters 
of  1.5  mm.  in  the  middle,  and  0.75  mm.  at  the  ends.  These  are 
weighed  empty,  and  also  filled  with  water;  the  difference  being  the 
weight  of  water  which  the  tube  contains.  The  water  is  then  blown 
out,  and  the  tube  filled  with  blood  and  again  weighed.  Subtraction 
of  the  weight  of  the  empty  tube  from  this  last  weight  gives  the 
weight  of  the  blood.  The  sp.  gr.  is  calculated,  as  usual,  by  dividing 
the  weight  of  the  blood  by  that  of  the  water. 

Reaction. —  Determinations  of  the  degree  of  alkalinity  of  the 
blood  must  be  made  as  soon  as  possible  after  the  sample  is  removed 
from  the  circulation  to  avoid  as  much  as  possible  the  minus  error  due 
to  diminution  of  alkalinity  (p.  553).  Lowy's  method  is  probably  the 
least  open  to  objection.  A  flask  is  used  having  a  long  neck,  upon 


556  MANUAL    OP    CHEMISTRY 

which  are  two  marks,  one  at  45  cc.,  the  other  at  50  cc.  This  is 
filled  to  the  45  cc.  mark  with  a  one -fourth  per  cent,  solution  of 
ammonium  oxalate,  and  5  cc.  of  blood  are  drawn  directly  from  the 
blood-vessel  into  it  to  the  50  cc.  mark,  and  the  contents  mixed. 
The  liquid  is  then  titrated  with  a  N/25  solution  of  tartaric  acid 
(3  gm.  tartaric  acid  to  the  litre),  using  a  lacmoid  paper  saturated 
with  strong  magnesium  sulfate  solution  as  an  indicator.  One  cc.  of 
this  solution  is  equivalent  to  0.0016  gm.  of  NaHO;  therefore  the 
number  of  cc.  nsed,  multiplied  by  200,  gives  the  alkalinity  in  parts 
p/m  of  NaHO. 

Haemoglobin. — Of  the  chemical  methods  of  determination  of  the 
quantity  of  haemoglobin  the  best  consists  in  incinerating  the  dried 
blood  and  determining  the  quantity  of  iron,  from  which  the  propor- 
tion of  haemoglobin  is  calculated. 

Of  the  optical  methods  the  most  accurate  is  probably  the  spectro- 
photometric  method  of  Vierordt,  or  one  of  its  modifications,  which 
depends  upon  measurement  of  the  proportion  of  light  of  a  certain 
wave-length  absorbed  in  passing  through  a  layer  of  a  definite  thick- 
ness of  the  blood,  diluted  in  known  proportion.  This  method, 
besides  yielding  accurate  results,  has  the  advantage  that  by  it  the 
proportions  of  oxyhaeinoglobin,  reduced  haemoglobin  and  carbon 
monoxid  haemoglobin  may  be  determined  in  the  same  sample.  It 
requires,  however,  a  spectroscope  specially  adapted  to  the  purpose. 
(See  Neubauer  and  Vogel,  Harnanalyse,  10th  ed.  pp.  680-696.) 

Colorometric  methods  depend  upon  comparison  of  depth  of  color 
of  the  specimen  of  unknown  content  with  standards  of  known  con- 
tent or  value.  When  such  comparisons  are  made  between  layers  of 
equal  thickness  of  solutions  equal  in  transparency  of  the  same  sub- 
stance, very  slight  differences  in  shade  may  be  easily  distinguished, 
and  accurate  results  may  be  obtained.  These  conditions  are  fulfilled 
in  the  haematinometer  of  Hoppe-Seyler  and  its  modifications,  in 
which  the  depth  of  color  of  the  blood,  diluted  in  known  proportion, 
is  imitated  in  the  comparison  apparatus,  with  a  solution  of  pure, 
crystallized  hemoglobin  of  known  strength.  When  the  two  samples 
have  precisely  the  same  shade,  the  proportion  of  haemoglobin  in  the 
comparison  sample  of  known  content  will  equal  that  in  the  diluted 
blood.  To  avoid  the  inconvenience  of  preparing  the  haemoglobin 
solution,  which  does  not  keep,  a  solution  of  carbon  monoxid  haemo- 
globin of  known  content,  which  is  permanent,  may  be  used,  if  the 
precaution  be  taken  of  converting  the  haemoglobin  in  the  blood 
sample  into  carbon  monoxid  haemoglobin  by  passing  CO  through  it 
before  making  the  comparison. 

The  different  forms -of  clinical  colorimeters,  known  as  haemo- 
globinometers,  such  as  FleishPs,  Oliver's,  Taylor's  and  Gower's,  are 


THE    BLOOD 

all  open  to  the  objection  that  the  comparison  of  tint  is  made  with 
colored  glasses,  or  with  solutions  of  colored  substances  other  than  the 
blood -coloring  matter,  and  consequently  not  identical  in  quality  with 
it.  While  these  instruments,  and  to  a  less  degree,  the  forms  of 
clinical  blood -testers  depending  upon  determinations  of  opacity  or 
of  specific  gravity,  may  afford  comparative  results  of  value  to  the 
clinician,  they  are  not  to  be  depended  upon  for  accurate  work.  For 
the  technique  of  clinical  blood  examination  the  student  is  referred  to 
the  excellent  article  by  Dr.  Camac  in  Wood's  Handb.  of  the  Med.  Sc. 
2d  Ed.  II.  37-71. 


CHANGES    IN    COMPOSITION    OF    THE    BLOOD    IN    DIFFERENT    PARTS  OF 

THE   CIRCULATION. 

As  the  blood -circulation  is  the  channel  through  which  the  mate- 
rials for  the  nutrition  and  functioning  of  the  different  parts  of  the 
body  are  carried  to  them,  and  by  which  the  waste  products  of  their 
activity  are  removed,  a  study  of  the  variations  in  the  composition  of 
the  circulating  medium  in  its  passage  through  different  organs  under 
varying  conditions  may  well  be  expected  to  throw  light  upon  the 
nature  of  normal  and  pathological  chemical  processes.  Unfor- 
tunately, the  difficulties  in  the  way  of  experimentation  are  great,  and 
but  little  has  yet  been  accomplished;  the  chief  impediment  being  the 
difficulty  of  obtaining  specimens  of  blood  from  the  two  sides  of  the 
organ  under  investigation,  which  are  comparable  with  each  other. 
The  abstraction  of  any  notable  quantity  of  blood  from  the  circulation 
at  a  given  point,  or  the  ligation  of  an  efferent  vessel  and  the  con- 
sequent stasis  in  the  organ  at  once  produce  pathological  conditions. 

The  situations  which  have  been  the  most  frequently  under  inves- 
tigation in  this  regard  are  the  hepatic,  the  pulmonary  and  the  renal 
circulations.  Changes  in  the  blood  in  the  last  named  may  be  inferred 
from  changes  in  the  composition  of  the  urine,  and  will  be  considered 
under  that  head.  The  chemistry  of  the  blood  changes  in  the  lungs 
is  a  portion  of  that  of  respiration  (see  pp.  560,  566). 

Changes  in  the  Liver. — As  all  the  products  of  digestion  which 
are  absorbed  from  the  alimentary  canal  by  the  blood  are  carried  by 
the  portal  vein  to  the  liver,  mixed  with  the  venous  blood  from  the 
spleen  and  pancreas,  and,  after  passage  through  the  hepatic  circu- 
lation, are  discharged  into  the  general  circulation  by  the  hepatic 
veins,  and  as,  moreover,  the  liver  is  furnished  with  blood  for  its  own 
nutrition  by  a  separate  supply  through  the  hepatic  artery,  it  would 
seem,  a  priori,  that  the  liver  should  act  as  an  adjunct  to  the  digestive 
apparatus  in  being  the  seat  of  further  chemical  changes  in  the 


558  MANUAL    OF    CHEMISTRY 

products  of  digestion,  preparatory  to  their  utilization  in  the  tissues. 
That  substances  absorbed  from  the  intestine  are  modified  chemically 
in  their  passage  through  the  liver  is  shown  by  the  fact  that  many 
poisons,  not  only  metallic  poisons,  such  as  arsenic,  copper,  and  lead, 
but  also  alkaloidal  poisons,  such  as  morphin,  strychnin,  atropiu, 
etc.,  when  injected  into  the  portal  vein,  act  with  only  one-half  to  one- 
third  the  intensity  as  when  injected  in  like  amount  into  the  jugular 
vein.  The  putrid  products  of  intestinal  origin  are  also  modified  in 
the  liver.  The  normal  portal  blood  of  the  dog  has  double  the  toxic 
power  of  the  blood  of  the  hepatic  veins  of  the  same  animal  when  in- 
jected into  the  peripheral  circulation  of  rabbits.  That  synthetic 
chemical  actions  take  place  in  the  liver  is  undoubted.  The  phenols 
produced  in  intestinal  putrefaction  there  combine  to  form  the  more 
complex  ester -sulf uric  acids,  certain  ammoniacal  compounds  are 
converted  into  urea,  and,  probably,  into  uric  acid.  Little  or  nothing 
is,  however,  known  of  the  nature  of  the  processes  to  which  the  pro- 
teins and  fats  are  subjected  in  the  liver;  or  of  the  products  of  such 
actions,  if  any  such  occur.  The  action  of  the  liver  upon  the  carbo- 
hydrates has  been  better  studied,  and  the  glycogenic  function  of  that 
organ  is  well  established. 

Glycogen  is  a  substance  closely  related  chemically  to  starch 
(p.  275)  which  exists  in  many  situations  in  the  body,  notably  in 
the  liver,  in  muscular  tissue,  and  in  embryonic  tissues,  in  each  of 
which  it  is  formed.  The  quantity  of  glycogen  in  the  liver  tissue  is 
influenced  by  several  conditions.  The  nature  of  the  diet  has  an 
influence  upon  the  quantity  of  glycogen,  not  only  in  the  liver,  but 
also  in  the  muscles.  The  usual  proportion  in  the  liver  is  12  to  40 
p/m.  With  a  diet  rich  in  carbohydrates  it  may  rise  to  120  to  160 
p/m.  In  starvation  it  disappears  from  the  liver  first,  and  subse- 
quently from  the  muscles;  and  that  more  rapidly  in  animals  of  small 
size  than  in  large  ones.  When  food  is  taken  the  glycogen -content 
increases,  to  reach  its  maximum  about  14  to  16  hours  after  the  meal. 
The  proportion  of  glycogen  in  the  liver  is  inversely  proportionate  to 
the  amount  of  muscular  activity,  and  with  violent  exertion  it  disap- 
pears entirely.  This  result  is  reached  in  rabbits  under  the  influence 
of  strychnin,  administered  to  the  extent  of  causing  tetanic  convul- 
sions, in  from  3  to  5  hours.  In  fevers,  also,  the  glycogen -content  of 
the  liver  is  diminished. 

Bearing  upon  the  origin  of  liver -glycogen,  it  has  been  found  to 
be  increased  in  amount  after  administration  of  monosaccharids  and 
disaccharids,  particularly  the  former,  dextrins,  starches,  glycerol, 
gelatin,  arbutin,  erythrite,  quercite,  dulcite,  mannite,  inosite,  glycols, 
saccharin,  glycocoll,  ammonium  salts,  amids,  narcotics,  hypnotics, 
and  antipyretics.  The  principal  glycogen -formers  are  undoubtedly 


THE   BLOOD  559 

the  carbohydrates,  although  it  is  also  formed  from  proteins.  The 
form  in  which  the  carbohydrate  material  is  utilized  by  the  liver  is 
that  of  the  three  monosaccharids,  glucose,  fructose,  and  galactose, 
which  are  the  products  of  intestinal  digestion.  Of  the  three  disac- 
charids,  cane  sugar  and  milk  sugar  are  eliminated  unchanged  if  in- 
jected into  the  circulation,  and  consequently  require  the  inversion  to 
which  they  are  subjected  in  the  intestine  before  they  can  be  utilized. 
Maltose,  on  the  other  hand,  is  inverted  in  the  blood,  and  is  probably 
absorbed  from  the  intestine  in  its  own  form.  The  conversion  of  the 
hexoses  into  glycogen  is  a  simple  process  chemically:  wCeH^Oe — nH^O- 
^/iCeHioOs,  but  by  what  mechanism  it  is  brought  about  in  the  liver 
cells  is  not  known.  That  glycogen  also  originates  from  some  proteins 
is  demonstrated  by  the  fact  that,  not  only  is  glycogen  produced,  but 
the  urine  also  contains  sugar  in  diabetics  from  whose  diet  carbo- 
hydrates have  been  completely  excluded;  although  glycogen  may  also 
be  produced  from  the  fats  in  the  animal  economy,  as  it  certainly  is  in 
the  vegetable.  Probably  a  part,  at  least,  of  this  glycogen  has  its 
origin  in  the  decomposition  of  glycoproteids,  but  possibly,  by  some 
unknown  processes  of  decomposition  and  synthesis,  other  proteins 
may  be  decomposed  into  a  carbohydrate  and  a  nitrogenized  factor. 
The  glycogen  existing  in  the  muscles  is  probably  not  carried  to  them 
by  the  blood  but  formed  in  them.  This  is  certainly  the  case  in  the 
embryonic  tissues,  which  are  very  rich  in  glycogen. 

That  glycogen  is  converted  into  glucose  in  the  liver  after  death  is 
certain,  and  that  a  similar  change  occurs  during  life,  probably  under 
the  influence  of  a  diastatic  enzym,  is  believed  by  most  observers, 
though  doubted  by  some.  When  the  liver  is  more  or  less  completely 
excluded  from  the  circulation,  in  geese,  the  sugar  rapidly  disappears 
from  the  blood,  or  is  at  least  diminished  by  one -half  or  one -third. 

The  part  played  by  the  liver,  if  any,  in  the  different  forms  of 
glycosuria  (p.  607)  is  still  an  open  question,  although  it  is  certain 
that  it  is  not  the  same  in  all  the  conditions  in  which  that  symptom 
exists.  The  blood  normally  contains  1.5  p/m  of  glucose,  which  is 
also  present  in  traces  in  normal  urine  (pp.  543,  596).  but  when  the 
proportion  in  the  blood  reaches  3  p/m  the  urine  contains  notable 
quantities  of  sugar;  glycosuria  exists.  The  power  of  the  kidneys  to 
prevent  the  passage  into  the  urine  of  more  than  traces  of  sugar  is 
therefore  limited;  and  glycosuria  may  be  caused  either  by  a  diminu- 
tion of  this  power  below  the  normal,  or  by  an  increase  of  sugar  in  the 
blood.  The  former  condition  is  known  to  exist  only  in  a  form  of 
artificial  diabetes,  produced  by  the  administration  of  phloridzin, 
which  is  a  glucosid  yielding  a  hexose  other  than  glucose  (p.  413)  on 
its  decomposition,  and  causing  the  formation  in  the  system  of  glucose 
from  protein  material.  Other  glycosurias  depend  upon  hypergly- 


560  MANUAL    OF    CHEMISTRY 

keemia.  This  may,  in  turn,  be  due  to  one  of  three  causes,  either  (1) 
the  passage  from  the  alimentary  canal,  through  the  liver,  and  into 
the  general  circulation  of  an  abnormally  large  amount  of  sugar;  (2) 
the  formation  in  the  liver,  or  elsewhere  in  the  system,  of  an  increased 
quantity  of  sugar;  and,  (3)  an  inability  on  the  part  of  the  system  to 
utilize  the  amount  of  sugar  normally  produced.  The  first  cause  is 
certainly  operative  in  alimentary  glycosuria,  due  to  a  diet  inordinately 
.rich  in  assimilable  carbohydrates.  It  is  probable  that,  even  under 
normal  conditions,  a  portion  of  the  sugars  of  the  portal  blood  pass 
through  the  liver  unchanged,  and  with  an  increased  richness  of  the 
portal  blood  in  carbohydrates  a  larger  proportion  will  naturally  escape 
the  retaining  action  of  the  perfectly  normal  liver.  Or  this  power  may 
be  pathologically  diminished,  as  is  probably  the  case  in  the  milder 
forms  of  diabetes,  in  which  the  glycosuria  readily  disappears  upon  reg- 
ulation of  the  diet,  and  also  in  some  forms  of  chronic  poisoning.  The 
second  cause  is  operative  in  glycosuria  attending  cerebral  ai\d  nervous 
lesions,  including  the  artificial  diabetes  caused  by  puncture  of  the 
floor  of  the  fourth  ventricle.  It  is  not  possible  to  exclude  this  cause 
also,  as  one  of  the  factors  in  the  severer  forms  of  true  diabetes,  in 
which  the  daily  elimination  of  sugar  may  go  as  high  as  500  to  1,000 
grams.  There  is  also  diminution  in  the  power  of  the  system  to  con- 
sume the  carbohydrates  in  true  diabetes,  as  well  as  in  the  glycosuria 
attending  diseases  of  the  pancreas,  and  in  the  severe  artificial  diabetes 
following  extirpation  of  that  organ.  It  has  even  been  suggested  that 
the  pancreas  produces  a  glycolytic  enzym,  by  which  glucose  is  nor- 
mally decomposed. 


CHEMISTRY    OF    RESPIRATION. 

The  function  of  respiration  is  a  physico-chemical  one,  the  purpose 
of  which  is  the  introduction  of  oxygen  into  the  system,  and  the  re- 
moval of  carbon  dioxid  and  water  therefrom.  In  so  far  as  it  is 
chemical,  the  subject  maybe  considered  under  the  following  heads: 
(1)  changes  in  composition  of  the  air;  (2)  changes  in  composition 
of  the  blood -gases  in  the  lungs;  (3)  tissue -respiration. 

Changes  in  Air.  —  The  average  composition  of  dry  atmospheric 
air,  in  volumes,  corrected  for  0°  and  760mm.  barometric  pressure, 
is:  Oxygen — 20.95,  nitrogen — 79.02,  carbon  dioxid — 0.03,  disregard- 
ing traces  of  other  gases.  The  proportion  of  carbon  dioxid  varies 
from  the  above  percentage  in  confined  spaces  (p.  306),  and  the  air 
always  contains  varying  quantities  of  vapor  of  water  (p.  103).  The 
expired  air  varies  somewhat  in  the  relative  proportions  of  its  con- 
stituents. Its  average  composition  is,  however:  oxygen  — 16.03, 


CHEMISTRY   OF   RESPIRATION  561 

nitrogen — 79.59,  carbon  dioxid — 4.38;  and  it  is  saturated  with  vapor 
of  water  at  the  temperature  of  the  body,  about  36°,  and  the  baro- 
metric pressure.  It  will  be  seen  that  the  proportion  of  nitrogen, 
which  is  a  mere  diluent,  remains  practically  unchanged,  and  that 
the  changes  which  the  air  undergoes  in  respiration  consist  of  the 
subtraction  of  4.92  volume -per  cent,  of  oxygen,  and  the  addition  of 
4.35  volume -per  cent,  of  carbon  dioxid  and  of  a  quantity  of  vapor  of 
water,  varying  with  the  degree  of  saturation  of  the  inspired  air. 
With  an  increased  degree  of  humidity  of  the  inspired  air  the  elim- 
ination of  water  by  the  skin  and  kidneys  is  increased. 

That  the  oxygen  taken  into  the  system  is  utilized  in  processes 
of  oxidation  which  take  place  in  the  tissues,  and  only  to  a  limited 
extent  in  the  lungs  and  blood,  is  now  generally  admitted.  If  the 
oxygen  taken  in  were  entirely  used  for  the  oxidation  of  carbon, 
and  if  there  were  no  source  of  oxygen  other  than  the  inspired  air, 
the  volume  of  oxygen  removed  from  the  inspired  air  should  equal 
the  volume  of  carbon  dioxid  added  to  it,  as  one  molecule  of  oxygen 
produces  one  molecule  of  carbon  dioxid.  But  the  volumes  are  not 
equal,  and  neither  of  the  above  conditions  exists.  All  tissues  and 
organic  food  constituents  contain  hydrogen  as  well  as  carbon,  and 
a  portion  of  the  oxygen  is  used  to  oxidize  this  to  water.  On  the 
other  hand,  they  all  contain  oxygen,  as  well  as  carbon  and  hydrogen, 
which  supplements  the  oxygen  derived  from  the  air.  Thus  180  grams 
of  glucose  produces  by  complete  oxidation  264  grams  of  carbon  di- 
oxid, and  108  grams  of  water,  for  which  288  grams  of  oxygen  are 
required,  of  which  the  glucose  itself  furnishes  96  grams,  or  one- third 
of  the  amount: 

C6H1206  •      +        602        =        6C02        +        6H20 
180  192  264  108 

Moreover,  carbon  dioxid  and  water  are  not  the  only  products  of 
oxidation  formed  in  the  body:  urea,  for  example,  is  a  product  of 
oxidation  of  the  proteins.  Thus  the  relation  of  oxygen  consumed 
to  carbon  dioxid  produced  depends  upon  many  conditions,  and  there 
is  always  an  apparent  loss  of  oxygen.  This  relation  is  known  as 
the  respiratory  quotient,  and  is  obtained  by  dividing  the  C02  pro- 
duced by  the  62  consumed.  Thus  in  the  above  proportions:  £#-= 

0.88.  The  fats  contain  10.73  to  11.91%  of  oxygen,  the  proteins 
21.5  to  23.5%,  and  the  carbohydrates  51.17  to  53.33%,  while  the 
amount  of  oxygen  required  for  the  oxidation  of  their  hydrogen  is, 
for  100  parts  each:  of  fats,  97.3  to  98.8;  of  proteins,  52.0  to  58.4, 
and  of  carbohydrates,  51.17  to  53.3.  It  is  clear,  therefore,  that 
the  carbohydrates  contain  sufficient  oxygen  for  the  oxidation  of  their 
hydrogen,  while  the  proteins  and  fats  require  additional  oxygen 

36 


562  MANUAL    OF    CHEMISTRY 

for  that  purpose,  and  that,  consequently,  the  respiratory  quotient 
will  vary  with  the  composition  of  the  diet.  It  also  varies  with  the 
amount  of  muscular  activity,  increase  of  which  is  attended  with  in- 
crease of  protein  oxidation,  and  with  marked  increase  of  production 
of  carbon  dioxid. 

In  considering  the  method  of  interchange  between  the  gases  of 
the  blood  and  those  of  the  air,  it  must  be  remembered  that  this 
exchange  takes  place  between  the  blood  and  the  air  contained  in 
the  alveoli,  and  that  this  is  not  completely  changed  in  respiration. 
Therefore,  the  composition  of  the  alveolar  air,  which  is  the  mixture 
formed  by  diffusion  between  the  air  remaining  in  the  alveoli  after 
expiration  with  that  taken  in  during  inspiration,  is  of  importance 
in  connection  with  the  method  of  gas  interchange.  The  composition 
of  alveolar  air  in  the  human  subject  can  only  be  implied  by  calcu- 
lation; but  experiments  upon  animals  have  shown  it  to  contain  3.6 
to  3.8  volume-per  cent,  of  carbon  dioxid  and  about  16  volume-per 
cent,  of  oxygen,  corrected  for  0°  and  760mm. 

Gases  of  the  Blood. — The  gases  which  the  blood  gives  off  when 
it  is  brought  into  a  vacuum  consist  of  oxygen,  carbon  dioxid,  nitro- 
gen, and  traces  of  argon.  The  amount  of  nitrogen,  including  argon, 
is  about  the  same  in  arterial  and  venous  blood  in  different  parts  of 
the  circulation,  i.e.,  from  1  to  2  volumes  in  100  volumes  of  blood. 
It  probably  takes  no  part  in  the  chemical  processes  of  the  body. 
The  blood -gases  in  which  interest  centers  are,  therefore,  oxygen 
and  carbon  dioxid.  The  methods  of  absorption  or  elimination  of 
these  gases,  and  the  form  in  which  they  exist  in  the  blood  may  be 
either  physical  or  chemical.  That  is  to  say,  they  may  pass  between 
blood  and  air  by  simple  diffusion,  or  by  a  so-called  "vitalistic" 
process,  which,  if  it  be  not  physical,  must  be  chemical ;  and  they 
may  exist  in  the  blood  in  simple  physical  solution,  or  in  a  form  of 
chemical  combination.  To  determine  which  of  these  methods  are 
operative,  and  in  what  degree,  is  a  subject  requiring  both  physical 
and  chemical  investigation.  We  briefly  recall  here  the  laws  gov- 
erning the  absorption  of  gases  by  liquids: 

When  a  gas  is  in  contact  with  a  liquid  it  may  either  dissolve  in 
or  combine  chemically  with  the  liquid.  In  either  case  it  is  said  to  be 
absorbed.  If  in  physical  solution  it  is  said  to  be  dissolved,  if  in 
chemical  combination  it  is  said  to  be  combined. 

The  co-efficient  of  absorption  of  a  gas  is  the  volume  of  that  gas, 
reduced  to  0°  and  760  mm.  Hg,  absorbed  by  unity  volume  of  the 
liquid  under  a  pressure  of  760  mm.;  and  it  varies  with  the  tempera- 
ture. Thus  the  coefficient  of  absorption  of  carbon  dioxid  in  water 
is  1.185  at  10°,  which  means  that  1  cc.  of  water  at  that  temperature, 
will  absorb  1.185  cc.  of  carbon  dioxid. 


CHEMISTRY  OF  RESPIRATION  563 

The  weight  of  gas  which  a  given  volume  of  liquid  will  dissolve  at 
a  given  temperature  is  directly  proportionate  to  the  pressure.  But 
as  the  volume  of  a  gas,  at  a  given  temperature,  varies  inversely  as 
the  pressure,  the  volume  of  gas  dissolved  is  independent  of  the  pres- 
sure; and  the  density  of  the  dissolved  gas  is  in  constant  relation  to 
that  of  the  undissolved  gas  in  contact  with  it.  Or,  in  other  words, 
the  pressure  or  tension  of  the  dissolved  gas  is  the  same  as  that  of  the 
free  gas  in  contact  with  it.  If  this  equality  be  disturbed  from  any 
cause,  as  by  variation  of  temperature,  the  gas  passes  into  or  out  of 
solution,  from  the  higher  to  the  lower  pressure. 

The  quantity  of  gas  dissolved  diminishes  with  increase  of  tem- 
perature, as  the  elastic  force  of  the  gas  increases. 

When  several  gases  are  dissolved  in  the  same  liquid,  each  is  dis- 
solved as  if  it  were  alone,  its  volume  being  estimated  at  the  pressure 
which  belongs  to  that  gas  in  the  mixture.  This  partial  pressure  is 
to  the  total  pressure  as  the  volume  of  the  gas  in  question  is  to  that 
of  the  mixture  under  the  same  conditions.  The  partial  pressure  may 

VXP 
be  calculated  by  the  formula  PP=  10Q  ,  in  which  V  is  the  volume- 

per  cent.* of  the  gas  in  question  in  the  mixture,  and  P  the  total 
pressure  in  mm. 

The  pressure  (tension)  of  a  gas  in  solution  may  be  experimentally 
determined  by  bringing  the  solution  in  contact  with  gaseous 
mixtures  containing  known  and  varying  proportions  of  the  gas  in 
question.  If  the  pressure  in  the  solution  be  less  than  the  partial 
pressure  in  the  mixture,  gas  will  be  dissolved,  while  gas  will  be  given 
off  from  the  solution  if  the  reverse  be  the  case.  By  analyzing  the 
gaseous  mixtures,  that  one  is  found  in  which  the  gas  under  investi- 
gation has  neither  increased  nor  diminished,  and  the  partial  pressure 
of  the  gas  in  it  equals  the  pressure  of  the  gas  in  the  solution. 

Oxygen. —  The  proportion  of  oxygen  in  arterial  blood  is  about 
21.6  volume -per  cent.  That  in  venous  blood  differs  in  different 
parts  of  the  venous  system.  An  average  of  many  analyses  of  the 
blood  of  the  right  heart  gives  its  oxygen -content  as  14.85  volume - 
per  cent.  As  the  coefficient  of  absorption  of  oxygen  in  water  at 
35°,  the  body  temperature,  is  0.0277,  the  maximum  amount  of  that 
gas  that  could  exist  in  solution  in  water  is  2.77  volume -per  cent., 
and  it  may  be  assumed  that  for  simple  solution  the  action  of  the 
blood  plasma  is  the  same  as  that  of  water.  Indeed,  analyses  of  the 
gases  from  blood -plasma  and  blood -serum  have  shown  the  presence 
of  0.26  volume -per  cent,  of  oxygen. 

It  follows  that  almost  all  of  the  oxygen  in  the  blood  exists  in 
some  form  of  chemical  combination  in  the  blood -corpuscles;  and  we 
have  seen  that  haemoglobin  is  capable  of  forming  such  a  combina- 


564  MANUAL    OF    CHEMISTRY 

tion.  It  has  also  been  shown  that  a  solution  of  freshly  prepared, 
pure,  crystallized  oxyheemoglobin  behaves  in  the  same  manner  as 
fresh,  defibrinated  blood  under  the  influence  of  reduced  pressures. 
The  dissociation  of  oxyhaemoglobin,  whether  in  solution  or  in 
defibrinated  blood,  under  reduced  pressures  also  shows,  by  the 
manner  in  which  it  takes  place,  that  the  oxygen  is  present  in  a 
"loose"  form  of  chemical  combination.  The  disengagement  of 
oxygen  does  not  begin  immediately  with  reduction  of  pressure, 
indeed,  this  may  be  reduced  to  about  half  an  atmosphere  without  any 
notable  disengagement  of  oxygen.  Operating  at  35°  to  39°,  the 
pressure  may  be  lowered  to  410  mm.  Hg  without  any  reduction  of 
the  oxygen -content  of  the  arterial  blood,  at  375  to  365  mm.,  it  is 
slightly  reduced,  at  300  mm.,  the  reduction  is  notable,  and  in  the 
vacuum  of  the  mercury  pump  the  oxygen  is  completely  given  off. 

As  to  the  process  by  which  the  oxygen  passes  from  the  alveoli 
into  the  blood:  if  the  oxygen  pressure  in  the  blood  be  less  than  the 
oxygen  partial  pressure  in  the  alveoli  the  physical  action  of  diffusion 
is  sufficient  to  transfer  the  gas  in  the  direction  of  the  lower  pressure, 
but  if  the  reverse  be  the  case  some  other  force  must  be  in  operation. 
We  have  seen  that  the  volume -per  cent,  of  oxygen  in  alveolar  air 
is  16,  which,  at  760mm.,  represents  a  partial  pressure  of  121.6mm. 
The  oxygen  pressure  in  arterial  blood  has  not  been  determined  with 
equal  certainty.  By  some  observers  this  value  is  given  as  75  to 
80mm.,  but  others  have  obtained  results  as  high  as  110  to  144mm. 
The  weight  of  evidence  appears  to  be  in  favor  of  the  lower  figures, 
and  of  the  consequent  view  that  the  passage  of  oxygen  from  the 
alveoli  to  the  blood  is  a  purely  physical  process. 

Carbon  Dioxid.  —  The  proportion  of  carbon  dioxid  in  arterial 
blood  is  30  to  40  volume -per  cent.,  usually  nearer  40.  The  pro- 
portion in  venous  blood  is  about  48  volume -per  cent.,  and  in  as- 
phyxia it  may  rise  as  high  as  69.21  volume -per  cent.  If  the  plasma 
and  corpuscles  be  separately  examined,  both  are  found  to  give  off 
carbon  dioxid,  and  that  in  the  relative  proportion  of  one -third  of 
the  entire  amount  from*  the  corpuscles  and  two -thirds  from  the 
plasma.  If  blood  be  introduced  into  a  vacuum  it  bubbles  and  gives 
off  all  of  its  gas,  but  if  blood  serum  or  plasma  be  subjected  to 
the  vacuum  a  portion  of  their  carbon  dioxid  is  retained,  and  is  only 
liberated  upon  addition  of  an  acid.  Therefore,  a  part  of  the  carbon 
dioxid  of  the  blood  exists  in  the  corpuscles  in  "loose"  combination, 
while  in  the  plasma  a  part  exists  in  that  condition,  or  in  solution, 
and  a  part  in  "  firm  "  combination ;  and  the  blood  corpuscles  act  like 
the  acids,  in  that  they  liberate  this  latter  portion  from  its  combi- 
nation. Indeed  oxyhasmoglobin  is  capable  of  expelling  carbon  dioxid 
from  alkaline  carbonates  in  a  vacuum.  Carbon  dioxid  apparently 


CHEMISTRY  OF   RESPIRATION  565 

exists  in  the  corpuscles  in  two  forms  of  combination.  It  is  in 
part  combined  with  haemoglobin  (p.  550),  probably  with  its  protein 
factor.  Another  portion  enters  into  reaction  with  the  alkaline  phos- 
phates, which  are  present  in  sufficient  quantity  to  form  alkaline 
bicarbonates  and  monophosphates. 

The  proportion  of  carbon  dioxid  existing  in  the  plasma  in  "  firm  " 
combination  has  not  been  accurately  determined.  Undoubtedly  it 
represents  the  alkaline  carbonates  resulting  from  decomposition  of 
the  bicarbonates  (see  below),  but  the  quantity  of  these  cannot  be 
determined  either  from  the  quantity  of  carbonate  left  on  incineration, 
or  from  the  degree  of  alkalinity  of  the  plasma,  because  the  former 
result  in  part  from  the  combustion  of  other  organic  compounds  of 
the  alkaline  metals,  and  the  latter  is  due  in  part  to  the  presence  of 
other  alkaline  compounds.  Nor  can  the  amount  of  carbon  dioxid 
which  is  not  removed  by  the  vacuum,  and  only  after  addition  of  an 
acid,  be  considered  as  representing  the  whole  of  the  firmly  combined 
carbon  dioxid,  because  other  substances  exist  in  the  plasma,  such 
as  the  globulins,  which  decompose  a  part  of  the  alkaline  carbonates 
in  a  vacuum.  It  can  only  be  stated  that  of  the  20  to  32  volume -per 
cent,  of  carbon  dioxid  in  the  plasma,  from  5  to  9  volume -per  cent, 
is  retained  in  a  vacuum,  and  probably  represents  a  large  part  of 
the  alkaline  carbonates  existing  in  the  blood  as  bicarbonates.  Such 
being  the  case,  a  notable  proportion,  at  least,  of  the  loosely  com- 
bined carbon  dioxid  must  exist  in  the  plasma  in  the  form  of  bicar- 
bonates (2NaHCO3=Na2CO3+CO2+H2O),  from  which  it  is  liberated 
in  vacuo  by  the  action  of  weakly  acid  substances,  such  as  the  glob- 
ulins. Indeed,  the  greater  part  of  the  carbon  dioxid  in  the  plasma 
is  probably  present  in  the  form  of  bicarbonates,  a  view  which  is 
further  supported  by  the  notable  diminution  in  the  amount  of  carbon 
dioxid  in  the  plasma  in  acidism  (diminished  alkalinity  of  the  blood), 
caused  either  by  administration  of  mineral  acids,  or  by  increased 
acid  formation  in  diabetic  coma,  in  which  the  total  carbon  dioxid 
in  the  plasma  may  fall  as  low  as  2  to  3  volume -per  cent,,  the  excess 
of  acid  taking  up  the  bases. 

A  portion  of  the  carbon  dioxid  of  the  plasma  is  also  in  simple 
solution.  By  the  method  described  on  page  563  the  carbon  dioxid 
pressure  in  arterial  blood  has  been  found  to  be  2.8%  of  an  atmos- 
phere, equivalent  to  a  pressure  of  21mm.,  of  Hg,  while  in  the  blood 
of  the  right  heart  3.81%=28.95mm.  Hg,  and  5.4%=41.04mm.  Hg 
have  been  found.  Comparative  results  between  the  carbon  dioxid 
pressures  in  the  blood  and  in  the  alveolar  air  are,  however,  not 
concordant.  According  to  some  observers,  the  blood  carbon  dioxid 
pressure  is  the  higher,  and  the  exit  of  carbon  dioxid  is  consequently 
a  purely  physical  process;  while,  according  to  others,  the  alveolar 


566  MANUAL    OP    CHEMISTRY 

partial  pressure  is  the  higher,  and  a  "vitalistic"  action  of  the  epi- 
thelial cells  is  invoked  to  overcome  the  higher  pressure.  The  oxygen 
entering  the  blood  is  also  supposed  to  play  a  part  in  expelling  carbon 
dioxid  from  its  chemical  combinations. 

Tissue  Respiration,  or  internal  respiration,  takes  place  between 
the  blood  in  the  capillaries  and  the  tissues,  through  the  lymph,  and 
consists  in  the  passage  of  oxygen  from  the  blood  to  the  tissues,  in 
which  the  oxidations  of  the  body  occur,  and  the  passage  of  the  car- 
bon dioxid  and  water  resulting  from  such  oxidations  in  the  opposite 
direction.  As  oxygen  enters  into  combination  in  the  tissues,  and  is 
thereby  removed  from  solution,  and  as  carbon  dioxid  is  there  pro- 
duced, it  is  clear  that  the  oxygen  pressure  in  the  tissues  must  become 
less  than  that  in  the  blood,  while  the  carbon  dioxid  pressure  in  the 
tissues  must  tend  to  increase,  and  therefore  the  simple  physical 
process  of  passage  from  the  greater  to  the  lesser  pressure  must  be  in 
operation. 

URINE. 

The  urine  is  the  only  pure  excretion  of  the  body,  its  formation 
has  but  one  object,  the  removal  of  waste  material,  and  it  is  the  prin- 
cipal channel  of  exit  from  the  body  of  water,  of  solid  products  of  dis- 
assimilation,  and  of  foreign  substances,  medicines,  poisons,  etc.,  more 
or  less  altered  by  the  chemical  change  in  the  body.  As  the  urine  is 
obtainable  without  difficulty,  and  as  it  varies  in  composition  with 
variations  in  the  chemical  processes  of  the  body,  analysis  of  the  urine 
affords  the  readiest  means  of  obtaining  insight  into  the  nature  of 
normal  chemical  processes  in  the  body,  and  of  pathological  departures 
therefrom.  The  form  in  which  medicinal  substances  are  eliminated 
in  the  urine  is  also  of  interest  to  the  pharmacologist,  as  indicating 
the  changes  which  they  have  undergone  in  their  passage  through  the 
system,  and  their  probable  method  of  action.  The  toxicologist  finds 
in  the  urine  the  last  traces  of  poison  undergoing  elimination. 


PHYSICAL    CHARACTERS. 

Consistency. — The  normal  urine  of  man  and  of  the  carnivora  is 
clear  and  transparent  when  voided.  On  standing  it  usually  soon  be- 
comes cloudy,  and  a  light  flocculent  cloud  of  "mucus,"  the  "nubecula" 
of  older  authors  which  contains  epithelium,  mucus  corpuscles,  and 
urates,  separates  and  remains  suspended  in  the  liquid.  The  urine  of 
the  herbivora  is  cloudy  when  voided  and  is  alkaline  in  reaction,  and 
human  urine  when  alkaline  in  reaction  is  also  cloudy.  When  the 


0 


URINE  567 

urine  is  not  perfectly  transparent  its  cloudiness  may  be  due  to  the 
presence  of  morphological  elements  and  casts  in  suspension,  or  to  the 
presence  of  phosphates  or  urates  which  have  become  insoluble. 
Phosphates  thus  separate  from  the  urine  when  the  reaction  becomes 
subacid,  and  they  disappear  on  addition  of  an  acid.  Urates  are  de- 
posited from  hyperacid  urines  and  do  not  dissolve  on  addition  of  acid 
to  the  urine.  Generally  the  urine  has  no  viscidity,  but  alkaline  urines 
containing  pus  are  sometimes  thick  and  "stringy."  When  shaken 
with  air,  the  bubbles  soon  disappear  from  the  surface  of  normal  urine, 
but  in  urines  containing  sugar  or  bile  the  froth  persists  for  quite  a 
time.  In  the  rare  condition  of  chyluria,  depending  upon  the  presence 
of  filaria  in  the  blood,  the  urine  is  turbid  and  has  the  appearance 
f  milk. 

Quantity. — The  average  normal  quantity  of  urine  passed  by  an 
adult  in  24  hours  is  1,200  to  1,500  cc.,  being  somewhat  less  in  the 
female  than  in  the  male;  and  in  children  absolutely  less,  but  rela- 
tively to  weight  more  than  in  adults.  The  quantity  is  increased  with 
increase  of  the  amount  of  liquids  ingested,  and  diminished  when  the 
secretion  of  perspiration  is  increased.  Polyuria,  i.  e.,  increased 
quantity  of  urine,  occurs  pathologically  in  diabetes  mellitus,  in  which 
it  is  frequently  3,000  to  5,000  cc.,  sometimes  10,000  to  25,000  cc., 
and  even  more,  in  diabetes  insipidus,  during  absorption  of  large  effu- 
sions, in  granular  atrophy  of  the  kidneys,  and  in  nervous  diseases, 
such  as  hysteria,  chorea,  and  epilepsy.  Oliguria,  i.  e.,  diminished 
quantity  of  urine,  occurs  in  continued  fevers,  in  acute  nephritis,  in 
chronic  parenchymatous  nephritis,  in  cardiac  diseases,  towards  the 
fatal  termination  of  all  diseases,  in  surgical  shock,  and  under  all 
conditions  in  which  water  is  otherwise  disposed  of,  as  in  diarrhoea, 
after  hemorrhages,  and  during  formation  of  dropsical  effusions. 

Specific  Gravity.  —  The  specific  gravity  of  the  mixed  urine  of 
24  hours,  when  the  amount  is  normal,  is  1,015  to  1,025.  The 
"corrected"  specific  gravity  is  the  observed  sp.  gr.,  corrected  to 
what  it  would  be  if  the  quantity  were  the  normal  amount  of  1,200 

cc.,  and  is  obtained  by  the  formula  D  =  p^-,  in  which  Q  is  the 

quantity  of  urine  in  24  hours,  and  d  the  last  two  figures  of  the 
observed  sp.  gr.  Example:  Q  =  600  cc.,  d  =20,  then  600  X  20  -*- 
1200  =  10;  sp.  gr. =1,010.  The  sp.  gr.  gives  a  rough  indication  of 
the  quantity  of  total  solids.  The  last  two  figures  of  the  sp.  gr., 
multiplied  by  2.33  gives,  in  normal  urine,  approximately  the  amount 
of  total  solids  p/m.  Example:  sp.  gr.  =  1,017,  17X2.33=39.61 
grams  of  solids  in  l,000cc.  This  rule  does  not  hold  good  if  the 
urine  contains  sugar  or  albumin.  Generally  the  sp.  gr.  varies 
inversely  as  the  quantity.  But  in  diabetes  mellitus  the  quantity 


568  MANUAL    OF    CHEMISTRY 

is  large  and  the  sp.  gr.  high.  The  quantity  is  diminished  and 
the  sp.  gr.  is  low  in  obstructive  suppression,  in  the  later  stages 
of  fatal  diseases  attended  with  defective  elimination  of  solids,  in 
oedema,  and  in  diseases  attended  with  copious  diarrhoea,  vomiting 
or  sweating.  For  methods  of  determining  sp.  gr.,  see  page  5. 

Color. — The  color  of  the  normal  urine  varies  from  a  very  pale 
yellow  to  a  brownish -orange,  being  darker  when  concentrated  than 
when  dilute,  and  also  darker  when  strongly  acid.  Clinically,  urines 
may  be  divided,  according  to  color,  into  pale,  normal,  high-colored, 
and  dark.  The  urine  is  pale  when  its  quantity  is  increased.  Nor- 
mally-colored urines  are  of  negative  significance  only.  High-colored 
urines  owe  their  color  to  the  presence  of  the  normal  urinary  coloring- 
matters  in  increased  amount  (p.  591).  They  occur  in  all  forms  of 
acute  febrile  disease,  and  indicate  increased  activity  of  tissue  change. 
Concentrated  urines  are  high-colored.  Dark  urines  vary  in  color 
from  orange -red  to  black.  Exceptionally  the  urine  may  be  dark 
from  the  presence  of  greatly  increased  quantity  of  normal  coloring- 
matter,  as  in  beri-beri;  but  usually  a  dark  urine  owes  its  color  to 
the  presence  of  an  abnormal  pigment:  red  or  reddish -brown  from 
the  presence  of  blood- pigment;  brownish -yellow,  greenish -brown  or 
dark -brown  from  bile  coloring -matters;  smoky,  violet  or  black  from 
derivatives  of  carbolic  acid,  resorcinol,  salol,  or  salicylic  acid;  golden- 
yellow  from  santonin;  yellow,  changing  to  blood -red  with  alkalies, 
from  chrysophanic  acid  (rhubarb,  cascara,  senna) .  In  chyluria  the 
urine  is  white  and  milky. 

Odor. — When  freshly  voided,  the  odor  of  the  urine  is  faint  and 
aromatic,  but  on  standing  it  rapidly  develops  the  urinous  odor,  and 
finally  that  of  ammonia.  Certain  food  and  medicinal  substances, 
such  as  asparagus,  copaiba  and  turpentine,  communicate  peculiar 
odors  to  the  urine.  In  diabetes  the  urine  has  a  faint,  but  distinct, 
"sweet"  odor. 

Reaction. —  The  reaction  of  the  urine  depends  largely  upon  the 
nature  of  the  diet.  In  herbivora  it  is  neutral  or  alkaline;  in  the 
carnivora  strongly  acid.  The  urines  of  suckling  herbivorous  animals 
and  that  of  adults  during  starvation,  conditions  in  which  the  animals 
are  practically  carnivorous,  are  acid.  The  reaction  of  the  normal 
human  mixed  urine  of  24  hours  is  always  acid.  Samples  collected 
at  different  times  of  the  day  may  be  normally  acid,  alkaline  or 
amphoteric.  After  meals  the  acidity  of  human  urine  diminishes, 
and,  during  the  period  of  greatest  activity  of  stomach  digestion,  it 
may  even  become  alkaline  (p.  516).  If  the  urine,  after  having  been 
voided,  is  kept  at  the  ordinary  temperature,  its  acidity  rapidly  dimin- 
ishes, and  it  becomes  alkaline  and  ammoniacal  from  decomposition 
of  the  urea.  It  then  becomes  cloudy,  from  deposition  of  phosphates, 


URINE  569 

sometimes  of  calcium  oxalate,  and  later  of  ammonium  urate.  The 
acidity  of  the  urine  may  be  increased  by  administration  of  dilute 
mineral  acids,  but  not  beyond  a  certain  degree.  It  may  be  dimin- 
ished by  administration  of  dilute  alkalies  or  of  vegetable  acids  or 
their  salts,  which  are  oxidized  in  the  system  to  carbonates.  The 
acid  reaction  of  the  urine  is  due,  to  some  extent,  to  the  presence 
of  carbonic  acid,  but  principally  to  that  of  monometallic  phosphates. 
Uric  acid  does  not  occur  free,  but  in  combination,  in  normal  urine; 
therefore  it  does  not  contribute  directly  to  the  acidity,  but  indirectly 
it  is  largely  concerned  in  the  production  of  the  acid  reaction.  The 
alkaline  phosphates  of  the  blood  are  converted  into  acid  phosphates 
and  urates  by  reaction  with  uric  acid  :  Na2HP(>4  +  CsEL^Oa  = 
NaH2PO4+NaC5H3N403;  and  a  further  formation  of  acid  phosphate 
from  alkaline  phosphate  results  from  the  action  of  sulfuric  acid, 
produced  by  oxidation  of  the  sulfur  of  the  proteins,  and  of  hydro- 
chloric acid  reabsorbed  with  the  peptones. 

The  acidity  is  more  intense  than  normal  in  concentrated  urines, 
in  fevers,  gout,  acute  articular  rheumatism,  leukaemia,  scurvy,  and 
sometimes  in  diabetes.  The  acidity  of  diabetic  urine  frequently  in- 
creases after  it  is  voided,  with  separation  of  crystals  of  uric  acid, 
from  the  formation  of  acids  by  fermentation.  The  reaction  may 
become  alkaline  from  the  presence  of  fixed  alkalies,  carbonates,  or 
alkaline  phosphates,  or  of  volatile  alkali,  ammonium  carbonate. 
Physiological  subacidity  or  alkalinity  is  always  due  to  the  former, 
which  are  also  the  cause  of  the  alkalinity  occurring  in  anaemia, 
after  cold  baths,  after  absorption  of  alkaline  transudates,  and  after 
administration  of  organic  acids  or  mineral  alkalies.  Alkalinity  from 
volatile  alkali  always  results  from  decomposition  of  urea,  which 
takes  place  in  the  bladder  in  cystitis. 

The  reaction  of  the  urine  has  an  important  bearing  upon  the 
formation  of  calculi.  Much  the  larger  proportion  of  urinary  calculi 
are  either  phosphatic  or  uric  acid,  and  the  conditions  of  reaction 
under  which  the  two  kinds  are  formed  are  the  diametrical  opposites; 
the  deposition  of  uric  acid  requires  a  strongly  acid  urine,  while  the 
phosphates  are  deposited  from  subacid  or  alkaline  urines.  Uric 
acid  calculi  and  "gravel"  are  more  usually  of  renal  origin,  phosphatic 
calculi  never.  When,  as  frequently  occurs,  a  uric  acid  calculus  forms 
the  nucleus  of  a  large  phosphatic  calculus,  the  uric  acid  nucleus 
was  formed  in  the  kidney  in  a  strongly  acid  urine,  and,  coming 
down  into  the  bladder,  has  been  the  cause  of  a  cystitis  by  mechanical 
irritation,  which,  in  turn,  has  produced  an  alkaline  or  subacid  urine, 
from  which  the  phosphates  have  been  deposited  upon  the  uric  acid 
nucleus. 

The  quality  of  the  reaction  is  best  determined  in  the  usual  way, 


570  MANUAL    OF    CHEMISTRY 

with  litmus  paper.  If  the  reaction  be  alkaline  the  blued  red  litmus  is 
allowed  to  dry  in  a  place  protected  from  acid  fumes.  If  the  color 
returns  to  red  on  drying  the  alkalinity  is  due  to  volatile  alkali,  while 
if  the  blue  color  persists,  it  is  due  to  fixed  alkali. 

The  determination  of  the  degree  of  acidity  cannot  be  accomplished 
in  the  usual  way,  by  titration  with  standard  alkaline  solutions.  As 
stated  above,  the  acidity  of  the  urine  is  due  almost  entirely  to  the 
presence  of  acid  phosphates,  notably  of  acid  sodium  phosphate,  or 
monosodic  phosphate,  NaH2PO4.  But  the  urine  also  contains  disodic 
(and  dipotassic)  phosphate,  Na2HP(>4,  whose  reaction  is  faintly  alka- 
line, the  two  salts  being  in  varying  proportion  to  each  other.  If 
now  an  alkaline  solution,  such  as  a  N/10  solution  of  caustic  soda  be 
added  to  the  mixture  of  the  two  salts  in  solution,  the  monosodic  salt 
is  converted  into  the  disodic  :  NaH2PO4+NaHO=Na2HPO4+H2O, 
and  a  time  is  reached  when  the  proportion  of  the  two  is  such  that  the 
reaction  is  not  neutral,  i.  e.,  without  influence  upon  the  indicator, 
but  amphoteric,  i.  e.,  turning  red  litmus  blue  and  blue  litmus  red. 
As  the  measure  of  the  degree  of  acidity  of  the  urine  is  the  amount  of 
phosphoric  acid  (P20s)  present  in  monometallic  phosphates,  the  de- 
termination of  the  acidity  depends  upon  that  of  phosphoric  acid  in  its 
two  forms  of  combination,  as  monometallic  and  dimetallic  salts. 
This  is  done  by  the  Freund-Lieblein  method:  The  total  phosphoric 
acid  (T)  is  first  determined  by  the  method  described  on  p.  575.  To 
another  sample  of  75  cc.  of  urine,  15  cc.  of  barium  chlorid  solution 
(100  gm.  BaCl2.2H20  to  the  litre)  are  added,  by  which  the  dimetallic 
phosphates  (M)  are  precipitated,  while  the  monometallic  phosphates 
(D)  remain  in  solution.  The  mixture  is  shaken,  and  filtered  and 
refiltered  until  the  filtrate  is  clear.  Sixty  cc.  of  the  clear  filtrate, 
representing  50  cc.  of  urine,  are  taken  for  a  second  phosphoric  acid 
determination  by  the  same  method.  As  in  the  treatment  with  barium 
chlorid,  there  occurs  a  partial  conversion  of  one  phosphate  into  an- 
other, by  reason  of  which  about  3%  of  the  phosphoric  acid  of  the 
dimetallic  phosphate  remains  in  solution  as  monometallic  salt,  a  cor- 
rection is  here  necessary,  and  is  made  by  subtracting  3%  from  the 
result  of  the  second  determination.  The  corrected  result  (D)  repre- 
sents the  phosphoric  acid  present  in  monometallic  phosphates. 

CHEMICAL    COMPOSITION. 

The  constituents  of  the  urine  may  be  divided  into  two  classes  : 
normal  and  abnormal.  Clinically  some  normal  constituents,  such  as 
sugar,  which  are  present  in  healthy  urine  in  quantities  so  small  as  1o 
escape  detection  by  the  tests  customarily  used,  but  are  greatly  in- 
creased in  disease,  are  ranked  as  abnormal  constituents.  It  is  clear 


that,  as  the  normal  constituents  are  constantly  present,  we  can  only 
obtain  indications  of  clinical  value  by  their  variations  in  quantity. 
The  mere  presence  in  detectable  quantity  of  the  abnormal  constituents 
indicates  a  pathological  condition,  the  gravity  of  which  is  frequently 
proportionate  to  the  quantity  of  the  abnormal  constituents  voided. 
Quantitative  determinations  of  both  normal  and  abnormal  constit- 
uents therefore  constitute  a  large  part  of  urine -analysis.  As  it  has 
been  found  that  the  elimination  of  all  constituents  of  the  urine  is 
subject  to  variation  at  different  times  of  the  day  under  different  con- 
ditions of  eating,  sleeping,  exercise,  etc.,  quantitative  results  ob- 
tained with  the  morning  urine  are  not  comparable  with  those  obtained 
from  afternoon  urine,  indeed  the  only  quantities  which  are  com- 
parable with  each  other  are  the  amounts  excreted  in  24  hours,  and  no 
quantitative  determination  should  be  made  except  with  samples  of  the 
mixed  and  measured  urine  of  24  hours. 

The  normal  constituents  of  the  urine  are  classified  into  the  two 
groups  of  mineral  and  organic. 


Th, 


MINERAL    CONSTITUENTS. 


ie  mineral  salts  are  chlorids,  sulfates,  and  phosphates  of  potas- 
sium, sodium,  ammonium,  calcium,  and  magnesium,  with  traces  of 
silicic  acid.  Of  the  bases  sodium  and  potassium  are  the  most 
abundant,  and  of  the  acidulous  factors  chlorin.  In  the  urine  of  24 
hours  the  quantity  of  acid  present  is  in  excess  of  that  required  to 
completely  neutralize  the  amount  of  base  present,  and  that,  notwith- 
standing the  fact  that  a  portion  of  the  bases  exist  in  organic  combi- 
nations not  here  considered;  from  which  it  follows  that  a  portion  of 
the  salts  must  be  incompletely  saturated,  or  acid  salts,  such  as  acid 
sodium  phosphate,  NaH2PO4,  and  it  is  to  these  that  the  urine  owes 
its  acidity.  It  is  convenient  to  classify  the  salts  of  the  urine  accord- 
ing to  their  acids,  rather  than  according  to  their  bases,  into  chlorids, 
sulfates  and  phosphates. 

Chlorids. — The  chlorids  present  are  those  of  all  the  bases  men- 
tioned above,  but  sodium  chlorid  largely  predominates,  and  it  is  usual 
to  calculate  all  of  the  chlorin  found  on  analysis  as  sodium  chlorid. 
The  usual  amount  of  chlorids  eliminated  is  from  10  to  15  gms.  NaCl 
in  24  hours.  It  is,  however,  subject  to  great  variations,  chiefly  due 
to  differences  in  the  quantity  of  salt  taken  with  the  food  by  different 
individuals.  The  elimination  is  less  during  the  night  than  during  the 
daytime.  When  NaCl  is  excluded  from  the  diet  its  elimination  by 
the  urine  ceases  before  it  disappears  from  the  blood.  Numerous  de- 
terminations of  chlorids  in  various  diseased  conditions  have  been 
made,  but  it  must  be  remembered  that  the  observed  departures  from 


572  MANUAL    OF    CHEMISTRY 

the  normal  may  be  due  in  large  part,  if  not  entirely,  to  variations  in 
the  amount  of  salt  ingested,  or  to  removal  of  chlorids  by  other 
channels.  The  extremes  of  reported  variations  are  from  0  to  50  gms. 
in  24  hours.  Diminished  elimination  has  been  observed  in  acute 
febrile  diseases,  scarlatina,  roseola,  variola,  typhus,  typhoid  pneu- 
monia, yellow  atrophy,  in  all  acute  renal  diseases  with  albuminuria, 
in  carcinoma  of  the  stomach,  gastric  ulcer,  anaemic  conditions, 
rickets,  melancholia,  idiocy,  dementia,  chorea,  paralysis,  impetigo, 
pemphigus,  during  formation  of  exudates,  with  diarrhoea,  and  in 
chronic  lead  poisoning.  Increased  elimination  occurs  in  acute  dis- 
eases during  reabsorption  attended  with  diuresis,  in  diabetes  insipi- 
dus,  during  the  polyuria  following  attacks  of  epilepsy,  and  in  general 
paresis  when  large  amounts  of  food  are  taken. 

The  usual  methods  of  quantitative  determination  of  chlorids 
are  by  titration  with  silver  nitrate  solution,  either  by  Mohr's  or  Vol- 
hard's  method.  The  former  is  the  most  generally  applicable  if  inter- 
fering substances  be  first  removed.  If  the  urine  contain  albumin, 
this  is  first  removed  by  coagulation  and  filtration.  Ten  cc.  of  the 
albumin -free  urine  are  placed  in  a  platinum  crucible  along  with  about 
1  gm.  of  pure  (Cl-free)  Na2COs  and  about  2  gm.  pure  KN03,  and 
evaporated  to  dryness.  The  residue  is  cautiously  heated  to  fusion, 
cooled,  dissolved  in  water,  and  faintly  acidulated  with  HNOs.  If 
bromids  or  iodids  be  present  they  must  be  removed  at  this  point 
by  adding  dilute  H2SO4  and  a  little  sodium  nitrite  to  the  solution,  and 
shaking  it  with  successive  portions  of  carbon  disulfid  until  colorless. 
The  aqueous  solution  is  placed  in  a  porcelain  dish,  with  a  similar  dish 
containing  an  equal  quantity  of  water  alongside  for  comparison  of 
tint;  a  few  drops  of  neutral  potassium  chromate  solution  are  added 
to  the  contents  of  each  dish;  and  the  silver  solution  is  gradually 
added  to  the  chlorid  solution  until,  after  stirring,  it  has  a  faint  red- 
dish tinge  as  compared  with  the  contents  of  the  second  dish.  The 
silver  solution  used  may  be  either  a  N/10  solution,  containing  17.00 
gm.  of  pure,  crystallized  AgNOs  to  the  litre,  each  cc.  of  which  repre- 
sents 0.00585  gm.  NaCl  in  the  10  cc.  of  urine  used;  or  a  solution 
containing  29.054  gm.  AgNOa  to  the  Hire,  each  cc.  of  which  repre- 
sents 0.01  gm.  NaCl.  The  result,  multiplied  by  1/10  the  quantity  of 
urine  in  24  hours,  gives  the  daily  elimination. 

Volhard's  method  consists  in  precipitating  the  chlorids  completely 
by  an  excess  of  silver  nitrate  (20  cc.  of  the  second  silver  solution 
mentioned  above)  filtering,  and  determining  the  excess  of  silver  salt 
in  a  portion  of  the  filtrate  by  titration  back  with  a  solution  of  potas- 
sium thiocyanate  containing  8.3  gm.  KCNS  to  the  litre  (2  cc.  of 
which  =1  cc.  AgNOa  solution)  using  a  solution  of  ammonio- ferric  alum 
as  an  indicator,  and  subtracting  this  from  the  total  AgNOa  added. 


URINE  573 

Sulfates. — The  sulfates  of  the  urine,  sodium  and  potassium  sul- 
Fates,  are  contained  only  in  small  amount  in  the  food;  they  are  in 
great  part  produced  in  the  system,  as  products  of  oxidation  of  the 
sulfur  contained  in  the  proteins.  The  average  daily  elimination  is 
equivalent  to  2.3  to  2.5  gm.  of  sulfuric  acid  (SO3).  The  relation  of 
nitrogen  to  sulfuric  acid  contained  in  the  urine  is  quite  constant  at 
5  N  to  1  SOa.  Sulfuric  acid  exists  in  urine  in  two  distinct  forms  of 
combinations:  as  "mineral  sulfates,"  i.  e.,  K2SO4,  and  Na2SO4,  (A), 
and  as  "ether  sulfates,"  i.  e.,  the  Na  and  K  salts  of  ester -sulfuric 
acids  corresponding  in  constitution  to  ethyl -sulfuric  acid  (p.  312)  but 
containing  phenolic  or  indolic  residues  (p.  589),  derived  from  intes- 
tinal putrefaction  (B).  The  relation  between  the  quantities  of  A 
and  B  are  quite  variable,  and  the  proportion  of  B  present  indicates 
the  degree  of  activity  of  putrefactive  changes  in  the  intestine,  or  of 
retention  and  reabsorption  of  their  products,  in  the  absence  of  admin- 
istration of  phenolic  compounds.  Under  normal  conditions  the  rela- 
tion is  about  A:B  ::  10:1.  The  proportion  of  B  is  increased  in  faecal 
retention,  in  obstructive  jaundice  (p.  536),  and  in  hypochlorhydria 
(p.  520).  In  poisoning  by  phenols  A  is  reduced  to  zero.  In  diar- 
rhoea both  A  and  B  are  diminished,  while  in  acute  leukaemia  both  are 
increased. 

The  quantity  of  sulfates  is  best  determined  gravimetrically.  The 
total  sulfates  A  +  B,  are  first  determined  as  follows:  8  cc.  of  strong 
HC1  are  added  to  100  cc.  of  urine  and  the  mixture  heated  to  boiling. 
While  still  hot  about  20  cc.  of  saturated  BaCb  solution  are  added, 
and  the  mixture  kept  on  the  water-bath  until  the  precipitate  has 
completely  subsided.  The  clear  liquid  is  decanted  off  through  a  small 
filter,  and  the  precipitate  washed  with  hot  water  three  or  four  times 
by  decantation,  and  finally  brought  upon  the  filter  and  there  washed, 
first  with  hot  water  until  the  washings  no  longer  become  cloudy  with 
dilute  H2SO4,  then  three  or  four  times  with  hot,  strong  alcohol,  and 
finally  twice  with  ether.  The  filter  and  precipitate  are  then  dried, 
the  precipitate  transferred  as  completely  as  possible  to  a  weighed 
platinum  crucible,  the  filter  burnt  upon  the  lid,  the  ash  added  to  the 
crucible,  which  is  then  heated  to  moderate  redness,  cooled  and 
weighed.  This  weight,  minus  that  of  the  empty  crucible,  is  the 
weight  of  BaSOifrom  100  cc.  of  urine;  which,  multiplied  by  0.34301, 
gives  the  amount  of  SOa  in  100  cc.,  and  this  multiplied  by  1/100  the 
quantity  of  urine,  gives  the  daily  elimination  of  total  sulfuric  acid 
(S03). 

For  the  determination  of  the  relation  of  A  to  B  another  sample 
of  100 cc.  is  mixed  with  100  cc.  of  an  alkaline  solution  of  BaH202+ 
BaCl2,  which  precipitates  A,  but  not  B.  The  mixture  is  stirred, 
allowed  to  settle  a  few  minutes,  and  filtered  through  a  dry  filter 


574  MANUAL    OF    CHEMISTRY 

into  a  diy  stoppered  graduate,  and  the  filter  washed  with  cold  water 
until  the  graduate  contains  100  cc.  The  contents  of  the  graduate, 
representing  50  cc.  of  urine,  are  transferred  to  a  beaker,  strongly 
acidulated  with  HC1,  and  heated  to  boiling,  by  which  B  is  decom- 
posed, with  formation  of  metallic  sulfates,  which  are  then  determined 
as  above.  The  amount  of  SOa  found,  multiplied  by  inr  the  quantity 
of  urine  in  24  hours,  gives  the  daily  elimination  of  sulfuric  acid 
(SOa)  in  ester -sulfates. 

Phosphates. — The  phosphates  present  in  the  urine  are  those  of 
sodium,  potassium,  calcium  and  magnesium.  The  Na  and  K  phos- 
phates are  known  as  alkaline  phosphates  (p.  570),  those  of  Ca 
and  Mg  as  earthy  phosphates.  About  two -thirds  of  the  total  phos- 
phoric acid  is  contained  in  the  alkaline  phosphates,  of  which  the 
sodium  salt  is  greatly  in  excess  of  the  potassium,  and  one -third  in 
the  earthy  phosphates.  The  average  elimination  of  phosphoric  acid 
(P2Os)  is  2.5  to  3  gm.  per  diem,  but  it  may  vary  within  normal 
limits  from  1  to  5  gm.  a  day.  This  variation  depends  largely  upon 
the  nature  of  the  diet,  the  amount  being  larger  with  an  animal  than 
with  a  vegetable  diet.  A  notable  quantity  of  phosphates  are  con- 
tained in  food  articles,  both  in  alkaline  and  in  earthy  combination, 
of  which  the  former  are  readily  absorbed,  while  the  latter,  being 
soluble  only  in  acid  liquids,  are  in  large  part  passed  with  the  faeces. 
A  part  of  the  urinary  phosphates  are  also  formed  in  the  system  as 
products  of  oxidation  of  the  phosphorus  existing  in  the  albumens, 
nucleoproteids,  nucleins,  protagon  and  the  lecithins.  The  propor- 
tion between  the  amounts  of  nitrogen  and  of  phosphoric  acid  elim- 
inated, sometimes  called  the  "relative  value"  of  phosphoric  acid,  is 
calculated  by  the  formula  N:P2O5:  :100:#.  Normally  the  value  of  x 
is  from  17  to  20;  thus,  taking  the  average  elimination  of  nitrogen 
as  14  gm.,  and  of  phosphoric  acid  as  2.5,  the  value  of  x  would  be 
17.85.  While  variations  in  this  relation  depend,  in  some  measure, 
upon  differences  in  the  composition  of  food  articles  ingested,  they 
also  depend  upon  differences  in  the  character  of  tissue  changes  which 
may  be  exaggerated.  The  value  of  x,  obtained  by  the  above  for- 
mula, would  differ  notably  according  as  the  N  and  P2O5  are  derived 
by  oxidation  of  albumens,  on  the  one  hand,  or  of  other  phosphorus- 
containing  substances  on  the  other: 

N  P          P2o5  x 

Albumens   .  .  /  15.CO  .    .0.42.    .    0.96.  .  .  N:P2Ofl:  :100:     6.40 

\17.60.    .0.85.    .    1.95.  .  .  N:P2O5:  :100:  11.07 

Nucleohiston  .    .    .    .16.86.    .3.03.    .    6.93.  .  .  N:P2O5:  :100:  41.10 

Protagon 2.80.    .1.23.    .    2.82.  .  .  N:P2O5:  :100:100.71 

Bone 6.44 26.76.  .  .  N:P2O5:  :100:415.52 

Lecithins 1.73.    .3.84.    .    8.79.  .  .  N:P2O5: :  100:508. 09 


URINE  575 

It  is  evident  from  the  above  that  an  increase  in  the  relative 
value  of  phosphoric  acid  may  be  expected  under  conditions  involving 
either  an  increased  tissue  change  in  bone,  with  elimination  of  its 
phosphates,  or  increased  metabolism  of  tissues  rich  in  nucleated  cells. 
Such  is  the  case  in  starvation,  in  which  both  the  absolute  and  rela- 
tive elimination  of  phosphoric  acid,  as  well  as  that  of  calcium  com- 
pounds, are  notably  increased.  With  increased  mental  activity,  also, 
the  elimination  of  earthy  phosphates  is  increased,  and  that  of  alka- 
line phosphates  diminished. 

Pathologically  the  elimination  of  phosphoric  acid  is  diminished 
in  acute  febrile  diseases,  chronic  nephritis,  amyloid  degeneration  of 
the  kidney,  hysteria,  Addison's  disease,  acute  yellow  atrophy  of  the 
liver,  and  in  lead  poisoning.  It  is  increased  in  convalescence  from 
acute  diseases,  meningitis,  epilepsy  and  leukasmia,  and,  particularly, 
in  "phosphatic  diabetes,"  in  which  the  elimination  of  phosphoric 
acid  may  reach  8  to  9  gm.  in  24  hours,  and  in  which  the  other 
symptoms  of  diabetes  are  present,  but  there  is  no  glycosuria.  In 
diabetes  mellitus  the  quantity  of  phosphoric  acid  is  subnormal,  par- 
ticularly when  the  quantity  of  sugar  is  large. 

The  earthy  phosphates  only  are  concerned  in  the  formation  of 
calculi.  So  long  as  the  reaction  of  the  urine  (p.  569)  remains  acid 
they  are  held  in  solution,  but  when  the  reaction  becomes  alkaline, 
or  even  on  loss  of  CO2  on  exposure  to  air,  the  insoluble  trimetallic 
salts  are  formed  and  deposited.  Alkaline  urines  are,  for  this  reason, 
almost  always  turbid,  and  become  clear  upon  addition  of  an  acid. 
It  is  in  such  urine  that  phosphatic  calculi  are  always  formed, 
usually  about  a  nucleus  of  uric  acid,  or  of  a  foreign  body.  If  the 
alkalinity  be  due  to  the  formation  of  ammonia,  the  ammonio  -  mag- 
nesium phosphate,  or  triple  phosphate,  Mg(NH4)P04,  is  produced, 
either  in  the  form  of  large,  tubular  crystals,  or  as  a  fusible  calculus. 

A  process  for  the  quantitative  determination  of  phosphoric  acid 
in  the  urine  is  based  upon  the  formation  of  the  insoluble  uranium 
phosphate,  and  upon  the  production  of  a  brown  color  when  a  solution 
of  a  uranium  salt  is  brought  in  contact  with  a  solution  of  potassium 
ferrocyanid.  Four  solutions  are  required:  (1)  a  standard  solution  of 
disodic  phosphate,  made  by  dissolving  10.085  grams  of  crystallized, 
non- effloresced  H.Na2PO4  in  H2O,  and  diluting  to  a  litre;  (2)  an  acid 
solution  of  sodium  acetate,  made  by  dissolving  100  grams  sodium  ace- 
tate in  H2O,  adding  100  cc.  glacial  acetic  acid,  and  diluting  with  B^O 
to  a  litre;  (3)  a  strong  solution  of  potassium  ferrocyanid;  (4)  a 
standard  solution  of  uranium  acetate,  made  by  dissolving  20.3  grains 
of  yellow  uranic  oxid  in  glacial  acetic  acid,  and  diluting  with  H^O  to 
nearly  a  litre.  Solution  1  serves  to  determine  the  true  strength  of  this 
solution,  as  follows:  50  cc.  of  Solution  1  are  placed  in  a  beaker,  5  cc. 


576  MANUAL    OF    CHEMISTRY 

of  Solution  2  are  added,  the  mixture  heated  on  a  water- bath,  and  the 
uranium  solution  gradually  added,  from  a  burette,  until  a  drop  from 
the  beaker  produces  a  brown  color  when  brought  in  contact  with  a 
drop  of  the  ferrocyanid  solution.  At  this  point  the  reading  of  the 
burette,  which  indicates  the  number  of  cc.  of  the  uranium  solution, 
corresponding  to  0.1  — P205,  is  taken.  A  quantity  of  H2O,  deter- 
mined by  calculation  from  the  result  thus  obtained,  is  then  added  to 
the  remaining  uranium  solution,  such  as  to  render  each  cc.  equivalent 
to  0.005  gram  P205. 

To  determine  the  total  phosphates  in  a  urine:  50  cc.  are  placed 
in  a  beaker,  5  cc.  sodium  acetate  solution  are  added;  the  mixture  is 
heated  on  the  water -bath,  and  the  uranium  solution  delivered  from  a 
burette,  until  a  drop,  removed  from  the  beaker  and  brought  in  con- 
tact with  a  drop  of  ferrocyanid  solution,  produces  a  brown  tinge. 
The  burette  reading,  multiplied  by  0.005,  gives  the  amount  of  P205 
in  50  cc.  urine;  and  this,  multiplied  by  -gV  the  amount  of  urine  passed 
in  24  hours,  gives  the  daily  elimination. 

To  determine  the  earthy  phosphates,  a  sample  of  100  cc.  urine  is 
rendered  alkaline  with  NHJiO,  and  set  aside  for  12  hours.  The 
precipitate  is  then  collected  upon  a  filter,  washed  with  ammoniacal 
water,  brought  into  a  beaker,  dissolved  in  a  small  quantity  of  acetic 
acid;  the  solution  diluted  to  50  cc.  with  H2O,  treated  with  5  cc. 
sodium  acetate  solution,  and  the  amount  of  P2(>5  determined  as 
above. 

Metallic  Elements. — The  metallic  elements  of  urinary  salts  are 
sodium,  potassium,  calcium,  and  magnesium.  Sodium  and  potassium 
are  present,  not  only  in  combination  with  mineral  acids,  but  also  in 
organic  combination,  as  in  the  urates.  The  daily  elimination  is  equal 
to  2-3  gm.  K2O,  and  4-6  gm.  Na2O;  or  K:Na  ::  2.5:5.  Calcium  and 
magnesium  are  present  principally  in  their  phosphates,  in  less  amount 
as  chlorids,  and  occasionally  their  urates  are  met  with  in  calculi. 
About  1  gm.  of  Ca  and  Mg  is  eliminated  in  24  hours,  in  the  propor- 
tion of  2/3  Mg  and  1/3  Ca. 

NORMAL   ORGANIC    CONSTITUENTS    OF   THE    URINE. 

Urea  — Carbamid  — H2N-CO-NH2— (p.  348)— is  the  most  abun- 
dant of  the  organic  constituents  of  the  urine,  and  is  the  chief  end- 
product  of  the  metabolism  of  the  proteins  of  the  body.  Normally, 
in  the  urine  of  adults  84  to  91%,  and  in  that  of  infants  73  to  76% 
of  the  total  nitrogen  of  the  urine  is  contained  in  urea,  the  remainder 
entering  into  the  composition  of  creatinin,  uric  acid,  xanthin  bases, 
ammoniacal  compounds,  carbamates,  hippuric  acid,  indoxyl-  and 
skatoxyl-sulfates  and,  exceptionally,  of  allantoin,  leucin  and  tyrosin. 


URINE  577 

It  is  highly  improbable  that  urea  is  formed  by  any  simple  tran- 
sition from  protein  substances  in  the  body.  Indeed  it  is  doubtful 
whether  it  can  be  produced  from  protein  material  outside  of  the 
body  by  a  single  reaction.  It  is  derived  from  both  the  "circulating" 
proteins,  i.e.,  those  contained  in  the  blood  and  lymph,  and  the 
"tissue"  proteins,  i.  e.,  those  which  exist  in  the  tissues,  and,  as  these 
include  almost  all  of  the  animal  proteins,  differing  from  each  other 
notably  in  structure,  it  is  probable  that  urea  is  produced  in  the 
system  by  more  than  one,  and  probably  by  several,  series  of  re- 
actions. 

The  formation  of  urea  from  ammonium  carbonate,  and  from 
other  ammoniacal  salts  convertible  into  the  carbonate,  is  a  simple 

dehydration:  OrC^Nn!  ~  2H2O  =  O:C  <JJ!;;,  which  is  readily 
effected  outside  of  the  body,  and  which  has  been  shown  to  take 
place  in  the  liver.  This  method  of  production  of  urea,  and  this 
seat  of  its  formation,  are  the  only  ones  which  have  been  positively 
demonstrated,  but  the  ammoniacal  compounds  are  far  removed  from 
the  proteins  in  the  scale  of  decomposition,  and  it  is  not  presumable 
that  urea  is  formed  in  the  liver  exclusively. 

Another  direct  progenitor  of  urea  by  simple  dehydration  is  am- 
monium carbamate:  O:C<^ON2H4 — H2O  =O:C\^NHJ,  which  has  been 

found  to  be  a  constant  constituent  of  the  blood  and  urine,  and  to 
be  greatly  increased  in  the  latter  after  the  ingestion  of  large  quan- 
tities of  calcic  hydroxid.  In  support  of  the  view  that  ammonium 
carbamate  is  converted  into  urea,  or,  at  all  events,  into  some  other 
substance,  in  the  liver,  it  is  stated  that  in  dogs  in  which  the  portal 
vein  has  been  made  to  empty  directly  into  the  vena  cava,  the  admin- 
istration of  ammonium  carbamate  produces  symptoms  of  carbamate 
poisoning,  which  are  not  observed  when  the  same  salt  is  administered 
to  animals  not  so  operated  upon. 

Carbamic  acid  is  amido-formic  acid  (p.  346),  the  first  term  of 
series  of  mono -amido- fatty  acids.  Other  amido-acids  of  the  same 
series,  such  as  glycocoll  and  leucin,  and  of  the  succinic  series,  as 
aspartic  acid,  are  also  undoubtedly  intermediate  products  in  the 
formation  of  urea.  On  oxidation  in  alkaline  solution  these  sub- 
stances yield  carbarnic  acid,  and,  on  the  other  hand,  they  are  con- 
stant products  of  decomposition  of  albumens  by  the  action  of 
oxidizing  agents,  or  of  mineral  acids,  as  well  as  by  that  of  proteo- 
lytic  enzymes  (p.  499),  but  to  what  extent  they  are  thus  formed 
in  the  system  is  undetermined.  It  cannot  be  doubted,  however, 
that  the  amido-acids  are  decomposed,  with  formation  of  urea,  prob- 
ably with  ammonium  carbamate  as  an  intermediate  product,  and 
that  such  formation  takes  place  to  a  notable  extent  in  the  liver. 

37 


578  MANUAL    OF    CHEMISTRY 

It  has  been  shown  that  glycocoll,  leucin  and  aspartic  acid,  contained 
in  arterial  blood,  which  is  made  to  traverse  the  isolated  livers  of 
dogs,  are  converted  into  urea  or  into  some  substance  closely  related 
to  it.  Another  fact  in  support  of  the  view  that  urea  is  produced 
from  leucin  in  the  liver  is  that,  while  this  amido-acid  is  not  found  in 
normal  urine,  it  makes  its  appearance  there  in  notable  quantity,  while 
the  proportion  of  urea  is  correspondingly  diminished,  in  yellow 
atrophy  and  in  acute  phosphorus  poisoning,  in  both  of  which  condi- 
tions the  function  of  that  organ  is  seriously  interfered  with. 

Another  method  of  formation  of  urea  is  through  creatin  (p.  336), 
which  is  known  to  be  a  product  of  the  metabolism  of  muscular  tissue, 
and  through  the  allied  hexon  bases,  lysatin,  arginin,  etc.,  which  are 
products  of  the  tryptic  digestion  of  proteins,  and  which  yield  urea 
under  the  influence  of  hydrolyzing  agents  (p.  499).  Creatin  is 
methyl -guanidin  acetic  acid  (p.  336),  and,  by  hydrolysis  it  readily 

/NH2 
yields  sarcosin,  or  methyl -glycocoll,  and  urea:   HN:C\     /CH2.COOH 

NN-CH3 

-j-H2O  =  HN<(cH3'C()OH+H2N-CO-NH2-  Tt  must  be  admitted,  how- 
ever, that  sarcosin  is  not  known  to  exist  in  the  body  in  its  own  form, 
and  that  a  large  part,  at  least,  of  the  creatin  formed  in  the  system  is 
eliminated  as  creatinin  (p.  585). 

Chemically  a  logical  method  of  formation  of  urea  is  that  from  the 
nucleoproteids,  through  the  xanthin  bases  and  uric  acid  by  pro- 
gressive oxidation  (p.  356).  That  the  nucleoproteids  yield  nucleins, 
and  that  the  purin  bases,  including  uric  acid,  are  derived  from  these 
cannot  be  doubted,  but  the  formation  of  urea  from  uric  acid  in  the 
system  has  been  questioned,  and  even  denied.  Yet  it  is  highly  prob- 
able that  such  formation  does  take  place.  The  constitution  of  uric 
acid  and  the  methods  of  its  synthesis,  notably  that  from  urea  and 
glycocoll  (p.  358)  indicate  that  by  hydrolysis  it  should  produce  urea 
and  a  monureid  (p.  351),  and  this  reaction  does  occur  outside  of  the 
body,  as  when  uric  acid  is  decomposed  into  urea  and  alloxan  by 
hydrolytic  oxidation  :  Cs^N^+^O+O^CO^H^CJ^C^.  It 
has  also  been  shown  experimentally  that  uric  acid  administered  to 
animals  is  in  large  part  eliminated  as  urea. 

The  quantitative  relations  of  the  several  nitrogenous  constituents 
of  the  urine  vary  greatly  under  different  conditions,  normal  and 
pathological.  Thus  the  amount  of  uric  acid  normally  varies  from 
1/35  to  1/60  of  the  amount  of  urea,  and,  as  stated  above,  under  patho- 
logical conditions,  urea  is  to  a  great  extent  replaced  by  leucin  and 
tyrosin,  which  are  not  present  in  normal  urine.  The  observed  varia- 
tions in  the  proportion  of  the  amount  of  nitrogen  contained  in  the 
urea  to  the  total  nitrogen,  have  extended  from  50  to  90%. 


UEINE  579 

Ithough  countless  so-called  quantitative  determinations  of  urea 
have  been  made,  very  little  is  known  of  the  actual  quantities  of  urea 
present  in  the  urine  under  different  conditions  of  health  and  disease. 
This  is  because  almost  all  of  the  processes  used,  and  all  of  those  in 
general  use,  include  in  their  results,  not  only  urea,  but  all  the  nitro- 
gen of  the  creatinin  and  a  part  of  that  of  the  uric  acid,  calculated  as 
urea.  Nor  do  the  results  of  these  methods  indicate  the  total  nitrogen. 
Therefore  in  the  statements  below,  relating  to  the  "quantity  of  urea," 
that  expression  must  be  considered  as  referring  to  this  large  fraction 
of  the  total  nitrogen,  including  all  of  that  contained  in  urea,  calcu- 
lated as  urea. 

In  the  present  condition  of  our  knowledge  more  valuable  results 
are  to  be  expected  from  determinations  of  total  nitrogen  (by  the 
Kjeldahl  method)  than  from  determinations  of  urea,  either  absolute 
or  in  the  sense  as  above  limited.  The  quantity  of  nitrogen  in  various 
food  articles  can  be  obtained  from  Konig's  tables,  and  from  these 
figures  the  quantity  of  nitrogen  ingested  in  a  weighed  dietary  can  be 
calculated.  On  the  other  hand,  determinations  of  the  total  nitrogen 
in  faeces  and  urine  for  the  same  period  will  give  the  amount  of  nitro- 
gen eliminated.  When  these  two  quantities  equal  each  other  the 
system  is  said  to  be  in  a  condition  of  "nitrogenous  equilibrium,"  a 
condition  which  is  approximately  fulfilled  in  health.  But  if  the 
amount  of  nitrogen  eliminated  exceeds  that  ingested,  the  excess  has 
its  origin  in  abnormal  protein  metabolism.  But  little  has  as  yet  been 
accomplished  along  this  line.  The  results  are  best  expressed  as 
nitrogen,  not  either  as  urea,  or,  as  has  been  proposed,  in  terms  of 
the  amount  of  nitrogen  contained  in  lean  meat  (3.4%).  The  normal 
elimination  of  nitrogen  is  from  10  to  16  gm.,  equivalent  to  21.4  to 
34.3  gm.  urea.  As  60  parts  of  urea  contain  28  parts  by  weight  of 
nitrogen:  urea  X0.467=nitrogen;  and  nitrogen  X2.143=urea. 

The  quantity  of  urea  eliminated  in  24  hours  is  subject  to  normal 
variations  according  to  age,  sex,  diet,  and  exercise:  In  new-born 
children  the  elimination  of  urea  is  insignificant.  By  growing  chil- 
dren the  amount  voided  is  absolutely  less  than  that  discharged  by 
adults,  but,  relatively  to  their  weight,  considerably  greater ;  thus, 
Harley  gives  the  following  amounts  of  urea  in  grams  for  each  pound 
of  body- weight  in  twenty-four  hours  :  Boy,  eighteen  months,  0.4; 
girl,  eighteen  months,  0.35;  man,  twenty-seven  years,  0.25;  woman, 
twenty-seven  years,  0.20.  During  adult  life  the  mean  elimination 
of  urea  remains  stationary,  unless  modified  by  other  causes  than 
age.  In  old  age  the  amount  sinks  to  below  the  absolute  quantity 
discharged  by  growing  children. 

At  all  periods  of  life  females  eliminate  less  urea  than  males. 
The  proportion  given  by  Beigel  differs  slightly  from  that  of  Harley, 


580 


MANUAL    OF    CHEMISTRY 


viz.:  one  kilo  of  male,  0.35  gram  urea  in  twenty-four  hours;  one 
kilo  of  female,  0.25  gram.  During  pregnancy  females  discharge 
more  urea  than  males;  but  very  shortly  after  delivery  the  amount 
sinks  to  the  normal,  below  which  it  passes  during  lactation. 

The  quantity  of  urea  eliminated  is  in  direct  proportion  to  the 
amount  of  nitrogen  contained  in  the  food.  The  ingestion  of  large 
quantities  of  watery  drinks  increases  the  amount,  and  a  contrary 
effect  is  produced  by  tea,  coffee,  and  alcohol.  With  insufficient 
food  the  excretion  of  urea  is  diminished,  although  not  arrested, 
even  in  extreme  starvation. 

The  question  whether  the  elimination  of  urea  is  increased  during 
violent  muscular  exercise  is  one  which  has  been  the  subject  of  many 
observations  and  of  much  discussion.  An  examination  of  the  vari- 
ous results  shows  that,  while  the  excretion  of  urea  is  slightly  greater 
during  violent  exercise  than  during  periods  of  rest,  the  increase  is 
so  insignificant  in  comparison  to  the  work  done,  and,  in  some  in- 
stances, to  the  loss  of  body -weight,  as  to  render  the  assumption 
that  muscular  force  is  the  result  of  the  oxidation  of  the  nitrogen ized 
constituents  of  muscle  improbable.  (See  Gamgee,  "Physiological 
Chemistry,"  I,  pp.  385-401,  for  a  full  review  of  the  subject.) 

The  percentage  of  urea  in  the  urine  of  the  same  individual  is 
not  the  same  at  different  times  of  the  day.  The  minimum  hourly 
elimination  is  in  the  morning  hours;  an  increase  begins  immediately 
after  the  principal  meal,  and  reaches  its  height  in  about  six  hours, 
when  a  diminution  sets  in  and  progresses  to  the  time  of  the  next 
meal.  Gorup-Besanez  gives  a  curve  representing  the  hourly  varia- 
tions in  the  elimination  of  urea,  which,  reduced  to  figures,  gives  the 
following: 


Hour. 

Urea  in 
Grams. 

Hour. 

Urea  in 
Grams. 

Hour. 

Urea  in 
Grams. 

8-  9  A.  M  
9-10  A.  M.   .     .     . 
10-11  A.  M  
11  A.  M.-12  M.       .     . 
12  M.-l  P.  M.    .     .     . 
1-2  P.  M  

1.5 
1.5 
1.4 
1.3 

1.8 
1  9 

4-  5  p.  M.     ... 
5-  6  p.  M.    .    . 
6-  7  P.  M.     ... 
7-  8  P.  M.     ... 
8-  9  P.  M.     ... 
9—10  P  M 

2.6 
3.1 
2.8 
2.5 
2.3 
2  0 

12-1  A.  M.  .  .  . 
1-2  A.  M.  .  .  . 
2-3  A.  M.  .  .  . 
3-4  A.  M.  ... 
4-5  A.M.  .  .  . 

5-6  A  M 

1.9 
1.9 
1.9 
1.8 
1.6 
1  G 

2-3  P.  M  

3  4  P.  M  

2.1 
2.3 

10-11  P.  M.      ... 
11-12  P   M       . 

2.0 
2  3 

6-7  A.  M.  .  .  . 

7-8  AM... 

1.6 
1  5 

The  total  of  which,  however,  represents  a  quantity  above  the 
normal. 

The  absolute  amount  of  urea  eliminated  in  twenty -four  hours 
is  increased  by  the  exhibition  of  diuretic's,  alkalies,  colchicum,  tur- 
pentine, rhubarb,  alkaline  silicates,  and  compounds  of  antimony, 


URINE  581 

arsenic,  and  phosphorus.  It  is  diminished  by  digitalis,  caffein, 
potassium  iodid,  and  lead  acetate;  not  sensibly  affected  by  quinin. 

In  acute  febrile  diseases  both  the  relative  and  absolute  amounts 
of  urea  eliminated  augment,  with  some  oscillations,  until  the  fever 
is  at  its  height.  There  is,  however,  no  constant  relation  be- 
tween the  amount  of  urea  eliminated  and  the  body  temperature. 
During  the  period  of  defervescence,  the  amount  of  urea  eliminated 
in  twenty -four  hours  is  diminished  below  the  normal;  during  con- 
valescence it  again  slowly  increases.  If  the  malady  terminate  in 
death  the  diminution  of  urea  is  continuous  to  the  end.  In  inter- 
mittent fever  the  amount  of  urea  discharged  is  increased  on  the 
day  of  the  fever  and  diminished  during  the  interval.  In  cholera, 
during  the  algid  stage,  the  elimination  of  urea  by  the  kidneys  is 
almost  completely  arrested,  while  the  quantity  in  the  blood  is  greatly 
increased.  When  the  secretion  of  urine  is  again  established,  the 
excretion  of  urea  is  greatly  increased  (60-80  grams  a  day),  and  the 
abundant  perspiration  is  also  rich  in  urea.  In  cardiac  diseases, 
attended  with  respiratory  difficulty,  but  without  albuminuria,  the 
elimination  of  urea  is  diminished  and  that  of  uric  acid  increased. 
In  nephritis,  attended  with  albuminuria,  the  elimination  of  urea  at 
first  remains  normal;  later  it  diminishes,  and  the  urea,  accumulating 
in  the  blood,  has  been  considered  by  many  as  the  cause  of  ura3mic 
poisoning.  It  appears  more  probable,  however,  that  the  symptoms 
of  uraBmia  are  due  to  the  retention  in  the  blood  of  alkaloidal  poisons 
normally  excreted  in  small  amount.  The  quantity  of  urea  in  the 
urine  is  also  diminished  in  all  diseases  attended  with  dropsical  effu- 
sions; but  is  increased  when  the  dropsical  fluid  is  reabsorbed.  In 
true  diabetes  the  amount  of  urea  in  the  urine  of  twenty -four  hours 
is  greater  than  normal.  In  chronic  diseases  the  elimination  of  urea 
is  below  the  normal,  owing  to  imperfect  oxidation. 

To  detect  the  presence  of  urea  in  a  fluid,  it  is  mixed  with  three 
to  four  volumes  of  alcohol,  and  filtered,  after  having  stood  several 
hours  in  the  cold;  the  filtrate  is  evaporated  on  the  water -bath,  and 
the  residue  extracted  with  strong  alcohol;  the  filtered  alcoholic  fluid 
is  evaporated,  and  the  residue  tested  as  follows: 

(1)  A  small  portion  is  heated  in  a  dry  test-tube  to  about  160° 
(320°  F.),  until  the  odor  of  ammonia  is  no  longer  observed;    the 
residue  is  treated  with  a  few  drops  of  caustic  potassa  solution  and 
one  drop  of  cupric  sulfate  solution.     If  urea  be  present,  the  biuret 
resulting  from  its  decomposition  by  heat  causes  the  solution  of  the 
cupric  oxid  with  a  reddish -violet  color.     The  same  appearance   is 
produced  in  solutions  containing  peptone  (Biuret  test). 

(2)  A  portion  of  the  residue  is  dissolved  in  a  drop  or  two  of 
,  and  an  equal  quantity  of  colorless  concentrated  HNOs  added;  if 


582  MANUAL    OF    CHEMISTRY 

urea  be  present  in  sufficient  quantity  there  appear  white,  shining, 
hexagonal  or  rhombic,  crystalline  plates  or  six-sided  prisms  of  urea 
nitrate  (Fig.  38). 

(3)  A  portion  dissolved  in  water,  as  in  (2)  is  treated  with  a  solu- 
tion of  oxalic  acid;  rhombic  plates  of  urea  oxalate  crystallize. 

Determination  of  Quantity  of  Urea  in  Urine. — It  must  not  be 
forgotten  that,  in  all  quantitative  determinations  of  constituents  of 

the  urine,  the  question  to  be  solved  is  not 
how  much  of  that  constituent  is  contained 
in  a  given  quantity  of  urine,  but  how 
much  of  that  substance  the  patient  is  dis- 
charging in  a  given  time,  usually  twenty- 
four  hours.  Quantitative  determinations 
are,  therefore,  in  most  cases,  barren  of 
useful  results,  unless  the  quantity  of  urine 
passed  by  the  patient  in  twenty -four  hours 

is  known;  and,  in  view  of  diurnal  variations  in  elimination,  unless 
the  urine  examined  be  a  sample  taken  from  the  mixed  urine  of 
twenty -four  hours. 

The  process  giving  the  most  accurate  results  is  that  of  Bunsen,  in 
which  the  urea  is  decomposed  into  C(>2  and  NHa,  the  former  of  which 
is  weighed  as  barium  carbonate.  Unfortunately,  this  process  requires 
an  expenditure  of  time  and  a  degree  of  skill  in  manipulation  which 
render  its  application  possible  only  in  a  well-appointed  laboratory. 

A  process  which  is  described  in  most  text -books  upon  urinary 
analysis,  and  which  is  much  used  by  physicians,  is  that  of  Liebig. 
As  this  method  is  one,  however,  which  contains  more  sources  of 
error  than  any  other,  and  as  it  can  only  be  made  to  yield  approxi- 
mately correct  results  by  a  very  careful  elimination,  as  far  as  pos- 
sible, of  those  defects,  it  is  not  one  which  is  adapted  to  the  use  of  the 
physician. 

Probably  the  most  satisfactory  process  in  the  hands  of  the  prac- 
titioner is  that  of  Hiifner,  based  upon  the  reaction,  to  which  atten- 
tion was  first  called  by  Knop,  of  the  alkaline  hypobromites  upon  urea 
(p.  349);  using,  however,  Dietrich's  apparatus,  or  the  more  simple 
modification  suggested  by  Rumpf ,  in  place  of  that  of  Hiifner.  The 
apparatus  (Fig.  39)  consists  of  a  burette  of  30-50  cc.  capacity,  im- 
mersed in  a  tall  glass  cylinder  filled  with  water,  and  supported  in 
such  a  way  as  to  admit  of  being  raised  or  lowered  at  pleasure.  The 
upper  end  of  the  burette  communicates  with  the  evolution  bottle  a, 
which  has  a  capacity  of  75  cc.,  by  means  of  a  rubber  tube. 

The  reagent  required  is  made  as  follows:  27  cc.  of  a  solution 
of  caustic  soda,  made  by  dissolving  100  grams  NaHO  in  250  cc. 
H2O,  are  brought  into  a  stoppered,  graduated  cylinder,  2.5  cc.  bromin 


are  added 


URINE 


583 


ire  added,  the  mixture  shaken,  and  diluted  with  water  to  150  cc. 
The  caustic  soda  solution  may  be  kept  in  a  bottle  having  a  rubber 
stopper,  but  the  mixture  must  be  made  up  as  required,  a  fact 
which,  owing  to  the  irritating  character  of  the  bromin  vapor, 
renders  the  use  of  this  reagent  in  a  physician's  office  somewhat 
troublesome.  The  bromin  is  best  measured  by  a  pipette  of  suit- 
able size,  having  a  compressible  rubber  ball  at 
the  upper  end. 

To  conduct  a  determination,  about  20  cc. 
of  the  hypobromite  solution  are  placed  in  the 
bottle  a;  5cc.  of  the  urine  to  be  examined  are 
placed  in  the  short  test-tube,  which  is  then 
introduced  into  the  position  shown  in  the 
figure,  care  being  had  that  no  urine  escapes. 
The  cork,  with  its  fittings,  is  then  introduced, 
the  pinchcock  6  opened,  and  closed  again  when 
the  level  of  liquid  in  the  burette  is  the  same 
as  that  in  the  cylinder.  The  decomposing  ves- 
sel a  is  then  inclined  so  that  the  urine  and 
hypobromite  solution  mix;  the  decomposition 
begins  at  once,  and  the  evolved  N  passes  into 
the  burette,  which  is  raised  from  time  to  time, 
so  as  to  keep  the  external  and  internal  levels 
of  water  about  equal;  the  CO2  formed  is  re- 
tained by  the  soda  solution.  In  about  half  an 
hour  (the  decomposition  is  usually  complete  in 
ten  minutes,  but  it  is  well  to  wait  half  an 
hour)  the  height  is  so  adjusted  that  the  inner 
and  outer  levels  of  water  are  exactly  even, 
and  the  graduation  is  read,  while  the  standing 
of  the  barometer  and  thermometer  are  noted 
at  the  same  time. 

In  calculating  the  percentage  of  urea  from 
the  volume  of  N  obtained,  it  is  essential  that 
a  correction  should  be  made  for  differences  of  temperature  and 
pressure,  without  which  the  result  from  an  ordinary  sample  of  urine 
may  be  vitiated  by  an  error  of  10  per  cent.  If,  however,  the  tem- 
.  peratnre  and  barometric  pressure  have  been  noted,  the  correction 
is  readily  made  by  the  use  of  the  table  (see  Appendix  B,  III), 
computed  by  Dietrich,  giving  the  weight  of  Ice.  N  at  different 
temperatures  and  pressures. 

In  the  square  of  the  table  in  which  the  horizontal  line  of  the 
observed  temperature  crosses  the  vertical  line  of  the  observed  baro- 
metric pressure  will  be  found  the  weight,  in  milligrams,  of  a  cc. 


PlO.  39. 


584  MANUAL    OF    CHEMISTRY 

of  N;  this,  multiplied  by  the  observed  volume  of  N,  gives  the  weight 
of  N  produced  by  the  decomposition  of  the  urea  contained  in  5  cc. 
urine.  But  as  60  parts  urea  yield  28  parts  N,  the  weight  of  N, 
multiplied  by  2.143,  gives  the  weight  of  urea  in  milligrams  in  5cc. 
urine.  This  quantity,  multiplied  by  twice  the  amount  of  urine  in  24 
hours,  and  divided  by  10,000,  gives  the  amount  of  urea  eliminated 
in  24  hours  in  grams.  If  the  result  be  desired  in  grains  the  amount 
in  grams  is  multiplied  by  15.432. 

Example. — Five  cc.  urine  decomposed;  barometer  =  736  mm.; 
thermometer  =  10°  ;  burette  reading  before  decomposition  =  64.2; 
same  after  decomposition  =  32.6;  cc.  N  collected  =  31.6.  From  the 
table  1  cc.  N  at  10°  and  736  mm.  BP  weighs  1.1593.  The  patient 
passes  1500  cc.  urine  in  24  hours  : 

31.6  XL  1593  =  36.6339  =  milligr.  N  in  5  cc.  urine. 
36.0339  X  2.14  =  78.3965  =  milligr.  urea  in  5  cc.  urine. 

78.3965X3000       _0 
—        P =  23.519  =  grams  urea  in  24  hours. 

23.519  X  15.432  =  362.94=  grains  urea  in  24  hours. 

In  using  this  process  it  is  well  to  have  the  urea  solution  as  near 
the  strength  of  one  per  cent,  as  possible;  therefore  if  the  urine  be 
concentrated,  it  should  be  diluted.  Even  when  carefully  conducted, 
the  process  is  not  strictly  accurate;  creatinin  and  uric  acid  are  also 
decomposed  with  liberation  of  N,  thus  causing  a  slight  plus  error;  on 
the  other  hand,  a  minus  error  is  caused  by  the  fact  that  in  the  decorn 
position  of  urea  by  the  hypobromite,  the  theoretical  result  is  never 
obtained  within  about  eight  per  cent,  in  urine.  These  errors  may  be 
rectified  to  a  great  extent  by  multiplying  the  result  by  1.044. 

A  process  which  does  not  yield  as  accurate  results  as  the  pre- 
ceding, but  which  is  more  easy  of  application,  is  that  of  Fowler, 
based  upon  the  loss  of  sp.  gr.  of  the  urine  after  the  decomposition  of 
its  urea  by  hypochlorite.  To  apply  this  method  the  sp.  gr.  of  the 
urine  is  carefully  determined,  as  well  as  that  of  the  liq.  sodae  chlo- 
rinatae  (Squibb's).  One  volume  of  the  urine  is  then  mixed  with 
exactly  seven  volumes  of  the  liq.  sod.  chlor.,  and,  after  the  first  vio- 
lence of  the  reaction  has  subsided,  the  mixture  is  shaken  from  time 
to  time  during  an  hour,  when  the  decomposition  is  complete;  the  sp. 
gr.  of  the  mixture  is  then  determined.  As  the  reaction  begins 
instantaneously  when  the  urine  and  reagent  are  mixed,  the  sp.  gr.  ot 
the  mixture  must  be  calculated  by  adding  together  once  the  sp.  gr.  of 
the  urine  and  seven  times  the  sp.  gr.  of  the  liq.  sod.  chlor.,  and  divid- 
ing the  sum  by  8.  From  the  quotient  so  obtained  the  sp.  gr.  of  the 
mixture  after  decomposition  is  subtracted;  every  degree  of  loss  in 
sp.  gr.  indicates  0.7791  gram  of  urea  in  100  cc.  of  urine.  The  sp. 


URINE  585 

•.  determinations  must  all  be  made  at  the  same  temperature;  and 
that  of  the  mixture  only  when  the  evolution  of  gas  has  ceased 
entirely. 

Finally,  when  it  is  only  desired  to  determine  whether  the  urea  is 
greatly  in  excess  or  much  below  the  normal,  advantage  may  be  taken 
of  the  formation  of  crystals  of  urea  nitrate.  Two  samples  of  the 
urine  are  taken,  one  of  5  drops  and  one  of  10  drops;  the  latter  is 
evaporated,  at  a  low  temperature,  to  the  bulk  of  the  former,  and 
cooled;  to  each,  three  drops  of  colorless  HNOs  are  added.  If  crystals 
do  not  form  within  a  few  moments  in  the  concentrated  sample,  the 
quantity  of  urea  is  below  the  normal;  if  they  do  in  the  unconcen- 
trated  sample,  it  is  in  excess.  In  using  this  very  rough  method, 
regard  must  be  had  to  the  quantity  of  urine  passed  in  24  hours;  the 
above  applies  to  the  normal  amount  of  1200  cc.;  if  the  quantity  be 
greater  or  less,  the  urine  must  be  concentrated  or  diluted  in  pro- 
portion. The  amorphous  white  ppt.  caused  by  HNOs  in  albuminous 
urine  must  not  be  mistaken  for  the  crystalline  deposit  of  urea 
nitrate. 

For  the  determination  of  total  nitrogen  5  cc.  of  urine  are  placed 
in  a  long -necked  Kjeldahl  digesting  flask  along  with  0.5  gm.  of 
CuSC>4  and  15  cc.  of  concentrated  H2S04.  The  flask  is  supported  at 
45°  to  the  horizontal  and  gradually  heated  until  white  fumes  are 
given  off;  10  gm.  of  K^SO*  are  then  added,  and  the  contents  of  the 
flask  heated  just  short  of  boiling  until  almost  colorless.  After  cool- 
ing, the  contents  of  the  digesting  flask  are  transferred  and  washed 
into  a  distilling  flask;  the  acid  is  nearly  neutralized  by  the  slow 
addition  of  NaHO  solution  (sp.  gr.  1.24) ;  a  few  pieces  of  granulated 
zinc  are  added,  and  then  a  moderate  excess  of  NaHO  solution,  where- 
upon the  flask  is  immediately  connected  with  a  bulb  tube  and  con- 
denser, so  arranged  as  to  deliver  the  distillate  into  a  recipient  con- 
taining 30  cc.  of  N/5  H2SO4  and  a  little  lacmoid  as  an  indicator.  The 
distillation  is  continued  until  about  2/3  of  the  liquid  have  passed 
over,  when  the  excess  of  H^SCU  remaining  in  the  recipient  is  deter- 
mined by  titration  with  N/5  NaHO  solution.  Each  cc.  of  N/5  acid 
neutralized  by  the  ammonia  formed  in  the  process  corresponds  to 
0.0028  gm.  of  nitrogen  in  the  5  cc.  of  urine  used.  A  blank  process 
must  be  conducted  with  reagents  alone  to  guard  against  error  from 
nitrogen  compounds  in  the  reagents  or  in  the  air. 

Creatinin  —  (p.  336)  is  the  lactam  of  creatin,  or  methyl- 
guanidin  acetic  acid,  from  which  it  is  derived  in  the  body  by  dehy- 
/NH2  /H-C° 

dration:  HN:C<    /CH2.COOH-H2O=HN:C<   /&„  and  extete  in 

~CH3  N-CH3 

the  blood  and  urine  of  adults,  and  in  traces  in  milk,  although  it  is 


586  MANUAL    OF    CHEMISTRY 

absent  in  the  urine  of  nursing  infants.  The  quantity  eliminated  is 
slightly  greater  than  that  of  uric  acid,  1.7  to  2.1  gm.  in  24  hours. 
It  appears  to  follow  the  same  variations  as  urea,  and  to  be  formed  in 
slightly  greater  amount  with  increased  muscular  activity.  But  little 
is  known  of  its  pathological  variations,  except  that  it  is  diminished 
in  amount  in  progressive  muscular  atrophy,  in  other  diseases  of  the 
muscles,  and  in  paralyses. 

It  is  quantitatively  determined  as  its  zinc  chlorid  compound:  240 
cc.  of  the  urine,  freed  from  albumin  and  sugar,  if  present,  by  coagu- 
lation and  fermentation,  are  placed  in  a  300  cc.  cylinder,  rendered 
alkaline  with  milk  of  lime,  precipitated  with  CaCl2  solution,  made  up 
to  300  cc.,  mixed  and  filtered.  Of  the  filtrate  250  cc.  (=200  cc. 
urine)  are  acidulated  with  acetic  acid,  and  evaporated  to  20  cc.  The 
residue  is  mixed  with  absolute  alcohol,  the  solution  made  up  to  100 
cc.,  allowed  to  stand  24  hours  and  filtered.  Of  the  filtrate  80  cc. 
(=160  cc.  urine)  are  placed  in  a  beaker  with  1  cc.  of  an  acid-free 
solution  of  zinc  chlorid,  sp.  gr.  1.2,  and  allowed  to  stand,  covered, 
in  a  cool  place  for  two  days.  The  crystalline  zinc-creatinin  com- 
pound is  collected  on  a  small,  weighed  filter,  washed  with  a  little 
alcohol  until  the  washings  are  free  from  chlorin,  dried  at  100°  and 
weighed.  The  weight  obtained,  minus  that  of  the  filter,  multiplied 
by  0.6243  gives  the  weight  of  creatinin  in  160  cc.  urine.  If  the  de- 
posit contain  sodium  chlorid,  recognizable  by  the  cubical  shape  of  the 
crystals,  it  is  treated  with  HNOs,  which  is  then  evaporated,  and  the 
residue  of  zinc  oxid  is  ignited,  washed  with  water,  dried  and  weighed. 
The  weight  of  zinc  oxid,  multiplied  by  0.244,  gives  the  weight  of 
creatinin. 

Uric  Acid  (p.  354) — is  present  in  the  urine  of  man  and  of  the 
carnivora,  and  is  particularly  abundant  in  the  solid  urine  of  birds 
and  reptiles,  which  consists  almost  entirely  of  ammonium  urate.  In 
the  urine  of  the  herbivora  it  exists  only  in  traces,  being  replaced  by 
hippuric  acid. 

With  regard  to  the  formation  of  uric  acid  in  the  system  it  may  be 
added  to  what  has  been  already  said  (see  Urea),  that  in  birds  a  syn- 
thetic formation  from  ammoniacal  salts  and  lactic  acid  in  the  liver 
seems  to  have  been  demonstrated,  although  it  is  not  probable  that  a 
similar  process  takes  place  in  man.  It  is  more  probable  that  the 
chief  source  of  uric  acid  is  from  the  nucleoproteids  by  the  method 
referred  to  under  urea.  The  fact  that  it  is  notably  increased  in 
amount  in  splenic  leukaemia  would  argue  in  favor  of  its  formation 
from  the  leucocytes.  Probably  the  greater  part  of  the  uric  acid 
formed  in  the  system  is  excreted  in  the  form  of  disodic  urate,  but  a 
part  is  also  probably  oxidized  to  urea  (p.  578). 

The  quantity  of  uric  acid  normally  present  in  the  urine  varies 


URINE  587 

notably  with  the  diet,  and  in  the  same  manner  as  urea.  With  a 
mixed  diet  the  average  daily  elimination  is  0.7  gm.;  with  a  vegetable 
diet  it  may  fall  as  low  as  0.3  gm.,  and  with  a  surfeit  of  animal  food 
it  may  rise  as  high  as  1.5  to  2.00  gm.  There  is  also  an  hourly  varia- 
tion, the  maximum  elimination  occurring  two  to  five  hours  after  the 
principal  meal,  and  the  minimum  is  thirteen  hours  after.  The  nor- 
mal relation  of  uric  acid  to  urea  varies  from  1:50  to  1:70. 

The  results  of  quantitative  determinations  in  pathological  condi- 
tions are  somewhat  conflicting,  and  those  obtained  by  the  older 
methods  are  for  the  most  part  erroneous,  being  affected  with  a  minus 
error.  The  following  facts  may,  however,  be  considered  as  estab- 
lished: In  leukemia  there  is  both  absolute  and  relative  increase,  the 
absolute  amount  being  from  1  to  5  gm.  in  24  hours,  and  the  pro- 
portion to  urea  increased  to  1:45  to  1:12.  A  similar  increase  occurs 
in  splenic  diseases,  and  in  hepatic  cirrhosis.  In  gout  there  is  dimin- 
ished elimination  during  the  chronic  period,  most  marked  just  pre- 
ceding an  attack,  and  an  increased  elimination  during  and  following 
the  exacerbations.  In  acute  articular  rheumatism  the  elimination 
increases,  to  return  to  and  fall  below  the  normal  during  con- 
valescence. In  diabetes  the  amount  of  uric  acid  is  usually  sub- 
normal, although  it  is  often  increased  to  as  high  as  3  gm.  in  24 
hours,  when  the  sugar  is  diminished  in  quantity.  By  reason  of  its 
very  sparing  solubility,  uric  acid  frequently  forms  sediments  and  cal- 
culi, consisting  either  of  free  uric  acid  or  of  the  less  soluble  of  the 
urates.  It  must  be  noted  in  this  connection  that  uric  acid  is  much 
more  soluble  in  the  presence  of  urea  than  in  pure  water.  While 
15,000  parts  of  water  are  required  to  dissolve  1  part  of  uric  acid,  the 
same  quantity  dissolves  in  1900  parts  of  a  2%  solution  of  urea,  about 
the  proportion  contained  in  the  urine. 

The  principal  methods  of  quantitative  determination  of  uric 
acid  are  those  of  Heintz,  of  Hopkins  and  the  Ludwig-Salkowski 
method.  The  older  method  of  Heintz,  which  consists  in  precipitation 
of  the  uric  acid  by  strong  acidulation  with  hydrochloric  acid,  and 
weighing  the  crystals,  is  frequently  inaccurate  by  reason  of  incom- 
plete precipitation  by  this  treatment;  indeed,  samples  are  met  with 
from  which  no  precipitation  whatever  occurs. 

Hopkins'  method  is  but  slightly  more  elaborate  than  Heintz's, 
but  much  more  reliable:  100 cc.  of  urine  are  saturated  with  powdered 
ammonium  chlorid  (for  which  about  30 gm.  are  required),  and  the 
solution  mixed  and  allowed  to  stand  2  to  3  hours  with  occasional 
stirring.  By  this  treatment  the  uric  acid  is  almost  completely  pre- 
cipitated as  acid  ammonium  urate.  The  precipitate  is  collected  on 
a  filter,  washed  with  saturated  NH4C1  solution,  and  dissolved  in  the 
smallest  possible  quantity  of  hot  water.  To  this  solution  5cc.  of 


588  MANUAL    OF    CHEMISTRY 

HC1  (1:3)  are  added,  and  the  mixture  evaporated  on  the  water  bath 
until  crystals  of  uric  acid  begin  to  form.  These  are  collected  upon 
a  small,  weighed  filter,  washed  successively  with  water,  alcohol  and 
ether,  dried  and  weighed.  A  correction  is  necessary  for  the  slight 
solubility  of  uric  acid,  which  is  made  by  adding  0.045  mgm.  for  each 
cc.  of  water  used  in  the  final  washing. 

The  Ludwig - Salkowski  method  is  more  accurate,  but  more  intri- 
cate, and  requires  to  be  rapidly  conducted  to  avoid  error.  It  de- 
pends upon  the  precipitation  of  the  uric  acid  as  its  silver  salt,  the 
decomposition  of  this  by  HC1,  and  the  collection  and  weighing  of 
the  liberated  uric  acid.  The  student  is  referred  to  more  comprehen- 
sive treatises  for  the  details  of  the  process. 

It  has  been  recommended  to  dissolve  the  precipitated  uric  acid 
in  the  Hopkins  and  Ludwig- Salkowski  methods  in  alkali  and  to 
titrate  the  solution  with  potassium  permanganate.  This  does  not 
materially  abbreviate  the  processes,  and  adds  further  sources  of 
error. 

Xanthin  Bases — (p.  356).  —  The  occurrence  of  guanin  and  of 
carnin  in  the  urine  has  not  been  demonstrated;  and  of  the  remaining 
xanthin  bases  which  are  met  with  in  the  urine  the  most  abundant 
are  heteroxanthin,  paraxanthin,  and  1-monomethyl- xanthin.  They 
are  normally  present  in  small  amount  only,  the  total  elimination 
being  from  15  to  45  mgm.  in  24  hours.  They  undoubtedly  originate 
in  the  metabolism  of  the  nucleoproteids,  and  are  increased  in  amount 
after  administration  of  nucleins,  and  in  conditions  attended  with 
increased  metabolism  of  leucocytes.  They  may  also  originate  from 
the  caffein  and  theobromin  contained  in  coffee,  tea  and  cocoa  (p.  358). 
Xanthin  occasionally  forms  vesical  calculi  of  considerable  size.  Their 
quantitative  determination  is  best  effected  by  Salkowski's  method, 
based  upon  precipitation  of  their  silver  compounds. 

Hippuric  Acid  —  (p.  425) — is  an  aromatic  amido-acid,  benzoyl- 
amido  acetic  acid,  which  exists  in  greatest  abundance  in  the  urine 
of  the  herbivora,  and  only  in  small  amount  in  normal  human  urine, 
although  the  daily  elimination  varies  within  quite  wide  limits,  0.29 
to  2.84gm.,  and  is  still  further  increased  when  benzoic  acid,  cinna- 
mic  acid  or  substances  containing  those  acids  or  their  compounds 
are  taken. 

Hippuric  acid  may  be  considered  as  formed  by  the  substitution 
of  the  radical,  benzoyl,  of  benzoic  acid  for  a  hydrogen  atom  in  the 
amido  group  of  amido-acetic  acid:  C6H5.CO.OH-hCH2.NH2.COOH= 
H2O+CH2.NH(C6H5.CO).COOH;  its  production  in  the  body,  there- 
fore, involves  the  formation  of  glycocoll  and  of  an  aromatic  deriv- 
ative which  may  supply  the  benzoyl  factor.  Both  of  the  constituents 
of  hippuric  acid  result,  undoubtedly,  from  protein  metabolism.  Gly- 


URINE  589 

cocoll  is  a  well -recognized  product  of  such  action,  but  the  method 
and  seat  of  production  of  the  benzoyl  radical  are  not  so  clear.  Ben- 
zoyl-propionic  acid,  CH.2(C6H5,CO).CH2.COOH,  is  known  to  be  a 
product  of  intestinal  putrefaction;  and  that  this  is  capable  of  yielding 
the  benzoyl  radical  is  demonstrated  by  the  fact  that  when  it  is 
injected  into  the  circulation  it  is  eliminated  as  hippuric  acid.  The 
administration  of  benzoic  acid  is  also  followed  by  a  corresponding 
increase  in  the  elimination  of  hippuric  acid.  That  some  of  the  steps 
in  the  formation  of  hippuric  acid  are  the  result  of  intestinal  putrefac- 
tion is  also  indicated  by  marked  diminution  in  its  elimination  in  dogs 
whose  intestines  are  disinfected.  It  is  possible,  also,  that  the  final 
steps  may  occur  in  the  kidney,  as  hippuric  acid  is  formed  when 
arterial  blood  containing  glycocoll  and  benzoic  acid  is  passed  through 
the  isolated  kidneys  of  dogs. 

Little  is  known  of  the  variations  in  elimination  of  hippuric  acid 
in  pathological  conditions. 

Oxaluric  Acid  — (p.  352)  — is  a  monureid,  (CON2H3)CO.COOH, 
which  exists  in  the  urine  as  its  ammonium  salt  in  very  small  amount. 
It  is  readily  decomposed,  even  by  boiling  its  solution,  into  urea  and 
oxalic  acid,  and  it  is  undoubtedly  concerned  in  the  formation  of 
the  oxalates  of  the  urine. 

Allantoin  —  (p.  353) — is  a  diureid  which  occurs  in  very  minute 
quantity  in  the  urine  of  adults,  in  somewhat  larger  amount  in  that 
of  pregnant  women,  and  in  that  of  infants  during  the  first  eight 
days  of  life,  when  the  quantity  of  urea  is  very  small.  It  is  in- 
creased in  the  urine  of  dogs  after  administration  of  uric  acid,  and 
is,  possibly,  produced  from  this  in  the  economy. 

Ester-sulfates. — The  occurrence  of  these  compounds  has  been 
referred  to  in  connection  with  the  sulfates  (p.  573),  and  they  are 
considered  here  at  greater  length,  as  the  most  important  among  them 
contain  nitrogen.  Their  constitution  is  similar  to  that  of  the  acid 
esters  (p.  311),  from  which  they  differ  in  containing  phenolic  in  place 
of  alcoholic  radicals.  Their  relations  are  shown  by  the  following 
f  ornmlaB : 

CH3  O.       ,OH 

I  >< 

CH2.O  O^    XO.CH2.CH3 

Ethylic  alcohol.  Ethyl-sulfuric  acid. 


<\S/°H 


Phenol.  Phenyl-sulfuric  acid. 


590  MANUAL    OF    CHEMISTRY 


O  OH 

\    / 

S  NH 

/  \       /      \ 

O  O.C=CH-C6H4 


Indoxyl-sulfuric  acid. 

The  compounds  of  this  class  which  are  known  to  occur  in  the 
urine  are  the  sodium  and  potassium  salts,  particularly  the  latter,  of 
the  ester -sulf uric  acids  of  phenol,  para-cresol,  catechol,  quinol,  in- 
doxyl,  and  skatoxyl. 

The  phenol  and  para-cresol  compounds  are  usually  determined 
together  by  precipitation  with  bromin  water,  by  a  method  which  is 
not  very  accurate,  and  which  determines  not  only  the  phenols  in  this 
form  of  combination,  but  also  that  existing  in  phenyl-glucuronic 
acid.  By  this  method  the  amount  of  phenol  and  para-cresol  elimi- 
nated has  been  found  to  vary  from  17  to  51  mgm.  in  24  hours.  They 
vary  inversely  as  the  mineral  sulfates  (p.  573),  at  whose  expense 
they  are  formed.  They  have  not  the  poisonous  qualities  of  the  phe- 
nols from  which  they  are  derived,  and  their  formation  serves  to  pro- 
tect the  system  not  only  from  the  toxic  effects  of  these  substances, 
when  formed  as  products  of  intestinal  putrefaction,  but  also  from  that 
of  carbolic  acid  to  the  limit  of  the  amount  of  sulfates  available.  In 
poisoning  by  carbolic  acid  the  whole  of  the  sulfuric  acid  of  the  urine 
is  in  ethereal  combination. 

Of  the  three  diphenols,  catechol  and  quinol  have  been  found  in 
the  urine  of  the  horse,  and  in  traces  in  human  urine.  The  third, 
resorcinol,  has  not  been  met  with  in  this  situation. 

Indoxyl-sulfates — Indican — Uroxanthin — (p.  465)  is  the  prin- 
cipal parent  substance  of  urinary  indigo,  which  is  also  derived  from 
indoxyl-glucuronic  acid.  The  origin  of  both  is  undoubtedly  in  the 
indole  produced  in  intestinal  putrefaction.  They  disappear  from  the 
urine  of  dogs  whose  intestines  are  disinfected,  they  are  not  present  in 
the  urine  of  new-born  infants,  and  they  were  also  absent  in  a  case  of 
artificial  anus  at  the  lower  part  of  the  ileum. 

The  amount  of  indigo  derivable  from  the  two  compounds  men- 
tioned, eliminated  in  24  hours,  is  from  5  to  20  mgm.  normally  in 
man.  In  some  of  the  lower  animals  it  is  much  greater,  in  the  horse 
25  times  greater.  It  is  nearer  the  higher  limit  with  animal  food, 
nearer  the  lower  with  a  vegetable  diet.  The  elimination  of  an  excess 
is  designated  as  indicanuria,  and  is  a  measure  of  the  intensity  of 
putrefactive  changes  taking  place  in  the  intestine.  Therefore  it 
occurs  in  hypochlorhydria  (p.  520)  from  any  cause.  But  in  the 
opposite  condition  of  hyperchlorhydria  in  gastric  ulcer  there  is  also 


URINE  591 

indicanuria.  Indicanuria  also  occurs  in  conditions  in  which  there  is 
diminished  peristalsis  of  the  small  intestine,  as  in  ileus  and  peri- 
tonitis, not  in  simple  constipation;  also  in  conditions  in  which  putre- 
factive changes  occur  in  the  body  elsewhere  than  in  the  intestine,  as 
in  empyema,  putrid  bronchitis,  gangrene  of  the  lungs,  etc. 

The  tests  used  for  the  detection  and  quantitative  estimation  of 
indoxyl  derivatives  in  the  urine  are  based  upon  their  decomposition 
by  hydrochloric  acid  into  indoxyl  and  sulfates,  and  the  oxidation  of 
the  former  to  indigo  blue. 

Obermayer's  modification  of  the  Jaff6  method  is  probably  the 
best:  The  urine  is  mixed  with  1/5  its  volume  of  20%  solution  of  lead 
acetate  and  filtered.  The  filtrate  is  mixed  with  an  equal  volume  of 
fuming  hydrochloric  acid  containing  3 : 1000  of  ferric  chlorid,  a  few 
drops  of  chloroform  are  added,  and  the  mixture  strongly  shaken  1  to 
2  minutes.  With  normal  urine  the  chloroform  remains  colorless  or 
almost  so;  but  if  an  excess  of  indoxyl  compounds  be  present  the 
chloroform  is  colored  blue,  and  the  depth  of  the  color  is  a  rough  indi- 
cation of  the  degree  of  the  excess.  The  best  method  of  more  exact 
quantitative  determination  is  Miiller's  spectrophotometric  method, 
which  is  based  upon  the  same  principle  as  Vierordt's  method  of 
haemoglobin  determination  (p.  556),  and  requires  similar  apparatus. 

Skatoxyl-sulfates — Urohaematin — correspond  in  constitution  to 
the  indoxyl -sulfates,  and  have  a  similar  origin.  Like  the  indoxyl 
compounds,  they  are  chromogens,  and  on  decomposition  they  yield 
red  or  violet  coloring -matters,  which  are  referred  to  as  "indigo  red." 
When  the  Obermayer  test  as  above  described,  but  before  addition  of 
chloroform,  is  applied  to  urine  containing  excess  of  skatoxyl  com- 
pounds, it  becomes  red  or  violet  in  color,  and  chloroform  when 
added  and  shaken  with  the  liquid  is  colored  red  or  violet.  The 
"reaction  of  Rosenbach  "  is  due  to  urohaematin.  It  consists  of  the 
addition  of  concentrated  nitric  acid  drop  by  drop  to  the  boiling  urine, 
which,  in  presence  of  excess  of  the  chromogen  urohasmatin,  assumes 
a  deep  wine -red  color,  which  is  usually  tinged  blue  from  the  presence 
of  indigo  blue.  Such  urines  also  turn  darker,  reddish,  violet,  or  even 
black,  from  the  surface  downwards,  on  mere  exposure  to  air. 

Urinary  Pigments  and  Chromogens. —  The  yellow  color  of  the 
urine  is  due  to  the  presence  of  more  than  one  coloring- matter.  The 
most  abundant  of  those  constantly  present  is  urochrom,  which  is 
accompanied  by  small  quantities  of  haematoporphyrin  (p.  551),  and 
by  a  chromogen,  urobilinogen,  which,  shortly  after  the  urine  is 
voided,  gives  rise  to  the  coloring -matter,  urobilin.  Besides  these  and 
the  indoxyl-  and  skatoxyl-compounds  already  mentioned,  the  urine 
frequently  contains  a  red  coloring -matter,  uroerythrin,  which  is, 
however,  not  constantly  present.  A  number  of  urinary  coloring- 


592  MANUAL    OF    CHEMISTRY 

matters  have  been  named,  which  are  probably  one  of  the  above- 
mentioned  or  products  of  the  action  of  acids  or  of  other  reagents 
upon  them  or  upon  other  constituents  of  the  urine. 

Urochrom  (of  Garrod) — is  closely  related  to  urobilin,  from  which 
it  differs  in  not  being  precipitated  by  saturation  of  its  solution  with 
ammonium  sulfate,  and  in  not  giving  either  the  spectrum  or  the 
fluorescence  of  urobilin.  The  two  substances  are  readily  converted 
one  into  the  other;  urochrom  into  urobilin  by  the  reducing  action 
of  aldehyde,  and  urobilin  into  urochrom  by  moderate  oxidation  with 
permanganate.  Urochrom  contains  nitrogen,  but  no  iron;  it  is 
amorphous,  brown,  soluble  in  water  and  in  dilute  alcohol,  sparingly 
soluble  in  strong  alcohol,  amylic  alcohol  or  acetic  ether,  insoluble 
in  ether,  chloroform  or  benzene.  It  is  precipitated  by  lead  acetate, 
silver  nitrate,  or  mercuric  acetate. 

Urobilin  (of  Jaffe) — does  not  exist  in  fresh  urine,  but  is  formed 
from  urobilinogen,  probably  by  the  action  of  light.  There  are  some 
differences  in  the  properties  of  urobilins,  as  described  by  different 
observers,  and  there  may  be  several  urobilins,  or  urobilinoids,  nor- 
mal, febrile,  etc.  Urobilin-like  substances  have  also  been  obtained 
from  bilirubin,  from  haematiu  and  from  haematoporphyrin,  and,  as 
they  have  been  formed  both  by  reduction  and  by  oxidation,  they 
cannot  be  identical  with  each  other.  Urobilin  is  apparently  identical 
with  the  stercobilin  of  the  faeces,  which  is  formed  in  the  intestine 
from  the  bile -pigments.  Both  the  urinary  and  the  faecal  pigment  are 
increased  in  amount  with  increased  intestinal  putrefaction. 

Urobilin  is  amorphous,  reddish -brown  to  reddish -yellow,  soluble 
in  alcohol,  amylic  alcohol  and  chloroform,  less  soluble  in  ether, 
sparingly  soluble  in  water,  in  which  its  solubility  is  increased  by 
the  presence  of  neutral  salts.  It  is  precipitated  completely  from  its 
solutions  by  saturation  with  ammonium  sulfate  after  addition  of 
sulfuric  acid.  It  is  soluble  in  alkalies,  from  which  solutions  it  is 
precipitated  by  acids.  It  is  precipitated  from  neutral  or  faintly 
alkaline  solutions  by  lead  acetate,  and  by  zinc  sulfate,  but  not  by 
mercuric  salts.  It  does  not  give  the  Gmelin  reaction,  but  gives  a 
reaction  similar  to  the  biuret  reaction.  Its  concentrated,  neutral, 
alcoholic  solutions  are  brown  in  color;  the  dilute  solutions  yellow 
or  rose-colored,  and  showing  a  strong  green  fluorescence.  The 
acid  solutions  have  the  same  colors,  are  not  fluorescent,  but  show 
a  faint  absorption  band  between  b  and  F.  If  zinc  chlorid  be  added 
to  the  ammoniacal  solution  it  becomes  red,  and  shows  a  fine  green 
fluorescence.  This  solution  gives  a  broad  absorption  band,  extend- 
ing from  about  midway  between  E  and  b  very  nearly  to  F;  and, 
if  concentrated,  a  second  band  over  E  appears  on  careful  acidulation 
with  sulfuric  acid. 


URINE 

ie  chromogen,  urobilinogen,  is  a  colorless  substance,  which 
may  be  obtained  by  precipitation,  caused  by  saturation  of  the  urine 
with  ammonium  sulfate;  or  may  be  extracted  from  the  urine,  acid- 
ulated with  acetic  acid,  by  agitation  with  acetic  ether.  It  is  soluble 
in  chloroform,  ether  and  amylic  alcohol.  Its  solutions  give  no  spec- 
trum, and,  on  exposure  to  light,  soon  become  colored,  from  conver- 
sion of  the  urobilinogen  into  urobilin. 

The  quantity  of  urobilin  eliminated  in  24  hours  has  been  vari- 
ously estimated  as  from  30  to  140  mgm.  Hoppe-Seyler's  method 
of  determination  consists  in  acidulating  100  cc.  of  urine  with  H2SO4, 
precipitating  by  saturation  with  (NELihSO-i,  collection  of  the  pre- 
cipitate after  24  hours,  washing  with  saturated  (NH^SO*  solution, 
extraction  of  the  residue  with  a  mixture  of  equal  parts  of  chloroform 
and  alcohol,  removal  of  alcohol  by  agitation  of  this,  filtered,  solution 
with  water,  evaporation  of  the  chloroform  solution  in  a  weighed 
beaker,  drying  at  100°,  washing  the  residue  with  ether,  drying,  and 
weighing.  By  this  method  Hoppe-Seyler  found  a  mean  of  123  mgm. 
in  24  hours,  and  extremes  of  80  and  140  mgm.  A  spectrophoto- 
metric  method,  based  upon  the  same  principle  as  those  for  haemo- 
globin and  for  indican,  also  gives  good  results. 

Pathologically  the  elimination  of  urobilinogen  is  increased  in 
conditions  involving  increased  metamorphosis  of  blood  corpuscles, 
in  fevers,  and  in  icterus,  in  chronic  lead  poisoning,  and  in  acute 
poisoning  by  antipyrin  and  antifebrin. 

Uroerythrin  exists  in  small  quantity  in  normal  urine,  and  is  the 
substance  which  gives  a  pink  or  red  color  to  "lateritious  deposits." 
It  is  soluble  in  amylic  alcohol,  forming  solutions  which  are  rose- 
colored  if  dilute,  orange  or  fiery -red  if  concentrated,  which  are  not 
fluorescent,  and  which  give  a  spectrum  of  a  single  band,  broader 
than  that  of  urobilin,  extending  from  midway  between  D  and  E 
nearly  to  F,  with  a  lighter  part  between  E  and  b.  Its  solutions 
are  colored  carmine -red  by  EbSO-t,  and  grass -green  by  alkalies.  A 
rough  method  for  detecting  its  presence  in  excess  consists  of  pre- 
cipitating the  urine  with  lead  acetate,  and  allowing  the  precipitate 
to  settle  for  15  minutes  in  the  dark.  In  presence  of  excess  of  uro- 
erythrin  the  precipitate  is  distinctly  pink,  otherwise  it  is  white. 

Uroerythrin  is  increased  in  amount  in  the  urine  after  violent 
exercise,  after  excess  of  food  or  of  alcohol,  in  disturbances  of  diges- 
tion, fevers,  and  derangements  of  the  hepatic  circulation. 

Cystin,  C3H6NSO2,  which  will  be  further  considered  under  the 
pathological  constituents,  is  really  a  normal  constituent  of  the  urine, 
but  is  present  only  in  traces,  not  exceeding  O.Olgm.  in  24  hours. 

Reducing  Substances.— The  reducing  power  of  uric  acid  has 
been  noticed  (p.  355).  The  normal  urine  also  contains  traces  of 

38 


594  MANUAL    OF    CHEMISTRY 

glucose,  not  sufficient  to  react  with  the  ordinary  reduction  tests,  but 
recognizable  by  them  after  concentration  and  extraction.  A  near 
product  of  oxidation  of  glucose,  glucuronic  acid,  CHO.(CHOH)4.- 
COOH  (p.  299),  is  also  present  in  conjugate  combination  with 
indoxyl,  skatoxyl,  and  phenolic  radicals,  and,  when  they  are  pres- 
ent, with  camphor  as  campho-glucuronic  acid  and  with  chloral  as 
urochloralic  acid.  Glucuronic  acid  is  formed  as  an  intermediate 
product  in  the  oxidation  of  glucose,  and  only  appears  in  the  urine 
when  protected  from  further  oxidation  by  combination  in  one  of 
the  forms  mentioned.  The  conjugate  glucuronic  acids  are  laBvogy- 
rous,  while  the  acid  itself  is  dextrogyrous.  They  are  readily  hy- 
drolysed  by  dilute  acids,  with  liberation  of  glucuronic  acid.  Thus 
urochloralic  acid  is  decomposed  into  glucuronic  acid  and  trichlor- 
alcohol:  CC13.CO.CH2.(CHOH)4.COOH  +  H2O  =  CHO.(CHOH)4.- 
COOH  +  CCla.CEbOH.  Glucuronic  acid  is  a  syrup,  but  forms 
crystalline  salts  ;  it  is  very  soluble  in  water  and  in  alcohol  ;  it 
reduces  the  salts  of  copper,  silver  and  bismuth;  is  not  fermentable, 
gives  the  furfurol  reaction,  also  the  phloroglucin  reaction  of  the 
pentoses,  and  forms  a  crystalline  compound  with  phenylhydrazin, 
which  fuses  at  115°. 

Oxalic  Acid  —  is  a  normal  constituent  of  the  urine  in  small 
amount,  not  exceeding  0.02  gm.  in  24  hours,  and  is  present  as 
calcium  oxalate,  held  in  solution  by  the  acid  reaction  of  the  rnono- 
sodic  phosphate.  It  is  partly  taken  in  with  the  food,  as  it  exists 
in  many  fruits  and  vegetables,  apples,  spinach,  sorrel,  asparagus, 
rhubarb,  etc.  But  it  is  also  produced  in  the  system  from  proteins 
and  fats,  as  it  does  not  disappear  from  the  urine  when  the  diet  is 
limited  to  these,  or  with  deprivation  of  food.  Calcium  oxalate  is 
frequently  deposited  from  subacid  urines  either  in  octahedral  crys- 
tals or  in  dumb-bells,  and  sometimes  forms  calculi,  mulberry  calculi, 
which  are  white,  hard  and  nodulated.  The  elimination  of  oxalic 
acid  is  increased  in  intestinal  disturbances,  sometimes  with  transient 
albuminuria,  and  sometimes  in  diabetes.  Idiopathic  oxaluria,  or  the 
oxalic  acid  diathesis,  is  a  condition  in  which  the  elimination  of 
oxalates  is  notably  increased,  the  cause  of  which  is  unknown.  In 
oxalic  acid  poisoning  the  elimination  of  the  poison  takes  place 
through  the  kidneys,  and  the  tubules  become  plugged  with  crystals 
of  calcium  oxalate. 

For  the  quantitative  determination  of  oxalic  acid  500  cc.  of 
urine  are  treated  with  CaCl2,  rendered  alkaline  with  ammonium  hy- 
droxid,  and  then  acid  with  acetic  acid.  In  24  hours  the  precipitate 
is  collected  upon  a  small  filter,  washed  with  water,  and  extracted 
with  dilute  hydrochloric  acid  (which  leaves  the  uric  acid  upon  the 
filter).  The  acid  solution  is  again  alkalized  with  ammonium  hy- 


UEINE  595 

Iroxid  and  the  precipitate  collected  upon  a  small  filter,  washed, 
dried,  burnt,  strongly  ignited  and  weighed  as  calcium  oxid.  The 
weight  of  CaO  found,  multiplied  by  2.2857,  gives  the  amount  of 
calcium  oxalate;  or,  multiplied  by  1.6071,  the  amount  of  oxalic  acid 
in  500  cc.  urine. 

Other  Constituents. —Besides  the  above,  the  urine  contains  a 
number  of  other  substances,  present  in  small  amount  or  imperfectly 
identified. 

The  total  sulfur  of  the  urine  is  greater  in  amount  than  can  be 
accounted  for  by  the  mineral  and  ethereal  sulfates,  the  excess  being 
about  20%  of  the  whole.  This  is  sometimes  referred  to  as  "neutral 
sulfur"  in  contradistinction  to  the  "acid  sulfur"  of  the  sulfates.  A 
small  portion  exists  in  cystin  (pp.  593,  617) ,  and  the  remainder  in  sub- 
stances of  very  diverse  nature.  Among  these  are:  (1)  a  thiocyanate, 
present  to  the  amount  of  about  .04  to  .11  p/m;  (2)  taurocarbamic 
acid,  NH2.CO.NH.C2H4.S02.OH,  and  (3)  taurin  itself,  derived  from 
the  decomposition  of  taurocholic  acid;  (4)  oxyproteic  acid,  a  com- 
pound containing  nitrogen  and  sulfur,  increased  in  amount  in  the 
urine  of  dogs  poisoned  with  phosphorus,  which  does  not  give  the 
xauthoproteic  or  biuret  reactions,  but  gives  a  weak  Millon  reaction; 
(5)  chondroitin-sulfuric  acid,  an  ester -sulf uric  acid  containing  ni- 
trogen, of  interest  in  connection  with  the  occurrence  of  albumen  in 
the  urine  (p.  603) ;  and  (6)  a  nucleoalbumen,  containing  sulfur, 
which  constitutes  the  so-called  mucus,  or  "nubecula." 

Nor  do  the  phosphates  of  the  urine  account  for  all  of  the  phos- 
phorus which  it  contains:  an  amount  corresponding  to  about  0.05 
gm.  P20s  in  24  hours  exists  in  some  form  of  organic  combination, 
such  as  phosphoglyceric  or  phosphosarcic  acid. 

Human  urine,  when  injected  into  the  circulation  of  animals,  is 
quite  poisonous.  Thus  rabbits  are  killed  by  an  average  amount  of 
45  cc.  of  normal  human  urine  per  kilo  of  weight  of  the  animal,  in- 
jected at  one  time.  The  urine  of  persons  suffering  from  febrile  dis- 
eases is  more  actively  poisonous  than  that  of  healthy  individuals. 
The  urine  excreted  in  the  early  morning  hours  is  more  active  than 
that  formed  during  the  day  and  early  night,  and  the  night  urine  pro- 
duces convulsions,  while  the  day  urine  behaves  as  a  narcotic  poison. 
The  urine  of  some  of  the  lower  animals,  notably  that  of  the  cat,  is 
still  more  poisonous  to  rabbits  than  human  urine.  The  toxicity  of 
the  urine  is  referable  in  part  to  the  action  of  the  potassium  salts 
(p.  182),  but  it  is  not  proportionate  to  their  quantity.  It  is  esti- 
mated that  about  45%  of  the  poisonous  action  is  due  to  potassium 
compounds;  the  remainder  being  due  in  part  to  the  urinary  coloring- 
matters,  in  part  to  the  moderately  toxic  quality  of  urea,  uric  acid, 
etc.,  and  in  part  to  the  presence  of  urinary  leucomains,  so-called 


596  MANUAL    OF    CHEMISTRY 

ptomams.  Several  observers  have  obtained  minute  quantities  of 
basic,  actively  poisonous  substances,  having  the  general  characters  of 
the  alkaloids,  from  normal  urine,  and  in  larger  amount  from  febrile 
urine.  The  exact  chemical  nature  of  these  bodies  is  not  determined, 
although  one  of  them,  Pouchet's  base,  has  been  obtained  in  the  crys- 
talline form,  and  was  found  to  have  the  composition  CyHuN^,  or 
C?Hi2N4O2.  True  ptomams,  such  as  cadaverin,  putrescin,  and  other 
diamins  have  also  been  found  in  pathological  urines,  notably  in 
cystinuria. 

ABNORMAL    CONSTITUENTS. 

Of  the  following  substances  some,  such  as  albumin,  ha3moglobin, 
etc.,  are  literally  abnormal  to  the  urine,  that  is  their  presence  in  any 
amount  is  the  result  of  a  pathological  condition;  others,  such  as 
glucose,  cystin,  etc.,  are  considered  abnormal  for  reasons  of  con- 
venience; they  are  normally  present,  but  only  in  very  minute  quan- 
tities, insufficient  to  be  revealed  by  the  tests  customarily  used, 
but  are  much  increased  in  amount  in  certain  pathological  conditions. 

Proteins. — The  proteins  which  may  occur  in  the  urine  are  serum 
albumin,  serum  globulin,  albumoses,  including  Briicke's  peptone,  and 
histon,  a  nucleoalbumen,  fibrin,  and  haemoglobin. 

Serum  Albumin  and  Serum  Globulin  —  are  usually  included  in 
the  term  "albumin,"  as  clinically  applied  to  the  urine,  as  both  re- 
spond to  the  tests  generally  used.  The  question  whether  albumin  is 
or  is  not  a  strictly  normal  constituent  of  the  urine,  in  the  sense  above 
indicated,  has  been  much  discussed.  The  weight  of  evidence  is, 
however,  in  favor  of  the  view  that  the  presence  of  albumin  is  always 
an  abnormal  condition.  That  it  may  be  present,  however,  in  quan- 
tities as  large  as  25  to  75  mgm.  to  the  litre,  in  the  urine  of  persons 
under  conditions  which  are  not  absolutely  pathological,  although  de- 
parting from  those  which  are  usual,  cannot  be  denied. 

Serum  albumin  and  serum  globulin  appear  in  the  urine  in  a  great 
variety  of  abnormal  conditions,  usually  in  quantity  not  exceeding  5 
p/m,  rarely  reaching  10  p/m,  and  very  exceptionally  50  p/m.  (1) 
Functional  albuminurias  include  those  conditions  which  are  sometimes 
considered  as  so-called  "physiologic,"  or  normal  albuminurias,  in 
which  the  presence  of  albumin  is  transitory  and  due  to  an  exaggera- 
tion or  deficiency  of  some  normal  condition;  after  severe  muscular 
exertion,  under  great  mental  strain  or  emotion,  in  anemic  children 
and  youths,  accompanying  excessive  elimination  of  uric  or  oxalic 
acid,  alimentary  albuminnria  due  to  excess  of  protein  diet,  particu- 
larly if  raw.  (2)  Febrile,  in  most  acute  febrile  diseases,  particularly 
during  convalescence.  In  typhoid  it  is  always  present,  and  disap- 


TVOQVCJ    rvn 


UEINE  597 


pears  on  the  fifth  to  the  eighth  day  in  light  cases,  on  the  tenth  day  or 
later  in  severe  cases.  In  pneumonia  albumin  is  always  present, 
sometimes  abundantly.  In  any  acute  febrile  disease  albumin  may  be 
present,  without  the  existence  of  any  structural  change  in  the  kidney. 
(3)  Circulatory,  due  to  disturbances  of  the  blood -pressure,  in  which 
the  quantity  of  albumin  is  usually  small,  as  in  valvular  heart -lesions, 
degeneration  of  the  heart  muscle,  diseases  of  the  coronary  arteries, 
impeded  pulmonary  circulation,  in  pregnancy  by  pressure  upon  the 
renal  veins,  after  cold  baths,  in  intestinal  catarrh  and  in  Asiatic 
cholera.  (4)  Hcemic,  due  to  pathologic  modification  of  the  blood 
proteins,  in  purpura,  scurvy,  leukaemia,  pernicious  anaemia,  jaundice, 
diabetes,  and  syphilis.  (5)  Toxic,  by  the  action  of  haematic  poisons 
such  as  lead,  mercury,  chloroform,  or  by  irritating  action  upon  the 
glandular  epithelium  of  the  kidney,  such  as  is  caused  by  mercury, 
cantharides,  oxalic  acid,  mineral  acids,  iodin,  phosphorus,  arsenic, 
antimony,  carbolic  acid,  salicylic  acid,  turpentine,  and  nitrates.  (6) 
Accidental,  by  the  presence  in  the  urine  of  blood,  pus,  or  semen.  So 
far  as  the  two  former  are  concerned,  they  may  be  either  renal,  or 
post -renal  in  origin.  (7)  Nephritic,  in  acute  nephritis  albumin  is 
present  in  large  amount,  as  much  as  5  to  20  gm.  in  24  hours,  and  the 
sediment  contains  casts.  In  chronic  parenchymatous  nephritis  albu- 
min is  also  constantly  present,  and  in  still  larger  quantity,  as  high  as 
15  to  30  gm.  in  24  hours.  In  chronic  interstitial  nephritis  the  amount 
is  small,  rarely  exceeding  2  to  5  gm.  in  24  hours,  and  variable,  while 
casts  may  be  absent.  In  amyloid  degeneration  the  amount  is  usually 
small,  although  it  may  reach  10  gm.  in  24  hours.  In  this  condition 
the  proportion  of  serum  globulin  to  serum  albumin  is  greater  than  in 
other  kidney  lesions,  it  is  usually  from  1:0.8  to  1:1.4.  Pure  glob- 
inuria,  that  is  the  presence  in  the  urine  of  serum  globulin,  unaccom- 
panied by  serum  albumin,  has  not  been  observed. 

For  the  detection  of  serum  albumin  and  serum  globulin  in  the 
urine  it  must  be  perfectly  clear.  If  not  so  it  is  to  be  filtered,  and 
if  this  does  not  render  it  transparent,  it  is  to  be  treated  with  a  few 
drops  of  magnesia  mixture  (p.  121  note),  and  again  filtered.  Or  the 
urine  is  shaken  with  kieselguhr  (diatomaceous  earth)  and  filtered. 

(1)  Heat  and  nitric  acid  test. — The  clear  urine,  if  alkaline,  is 
rendered  just  acid  by  addition,  guttatim,  of  dilute  acetic  acid  (nitric 
acid  should  not  be  used,  and  the  acidulation  is  imperative).  The 
urine  is  now  heated  to  near  boiling,  and  if  a  cloudiness  or  coagulum 
be  formed,  nitric  acid  is  added  slowly  to  the  extent  of  about  ten 
drops.  If  heat  produces  a  cloudiness  which  clears  up  completely  on 
addition  of  nitric  acid,  it  is  due  to  excess  of  earthy  phosphates.  If 
•a  cloudiness  caused  by  heat  do  not  clear  up  (it  may  increase)  on 
addition  of  nitric  acid,  it  is  due  to  serum  albumin  or  serum  globulin. 


598  MANUAL    OP    CHEMISTRY 

Sometimes  the  urine  after  heating  and  addition  of  nitric  acid 
deposits  a  granular  sediment  on  cooling;  this  is  due  to  the  separa- 
tion of  urates. 

(2)  Heller's  test  —  is  more  delicate  than  the  above,  and  reacts 
with  urine  containing  0.002  per  cent,  of  albumin.  About  1  cm.  of 
nitric  acid  is  placed  in  a  test-tube,  which  is  then  held  at  an  angle 
and  the  urine  is  allowed  to  flow  slowly  from  a  pipette  upon  the  sur- 
face of  the  acid  (Fig.  40)  so  as  to  form  a  distinct  layer  with  the 
minimum  of  mixing  of  the  two  liquids.  The  procedure  frequently 
directed,  of  "underrunning"  the  acid  from  a  pipette  under  the  urine, 
placed  in  a  test-tube,  does  not  give  as  good  results.  After  with- 
drawing the  pipette,  the  test-tube  is  returned  to  the  vertical  slowly, 
and  the  line  of  junction  of  the  two  liquids  examined  against  a  dark 
background.  If  the  urine  contain  albumin  a  white,  opaque  band, 
whose  upper  and  lower  borders  are  sharply  defined,  will  be  seen  at 
the  line  of  junction  of  the  two  liquids.  A  colored  band  is  generally 
observed  in  applying  this  test,  which  has  no  relation  to  the  presence 

of  albumin,  it  may  be  of 
some  shade  of  red  from  the 
presence  of  excess  of  normal 
coloring  matter,  or,  of  uro- 
erythrin,  blue,  or  almost 
black,  from  the  presence  of 
indican  in  excess,  or  giving 

PlG  40  the  colors  of  the  Gmelin  reac- 

tion (p.  528)  in  the  presence 

of  bile.  When  urates  are  present  in  excess  a  white  zone  is  also  formed 
which,  however,  differs  from  that  caused  by  coagulation  of  albumin  in 
the  following  particulars:  it  is  not  at,  but  slightly  above,  the  line  of 
contact  of  the  two  liquids;  while  its  lower  border  may  be  sharply 
defined,  it  has  no  upper  border,  but  shades  off  gradually  in  the 
upper  layer;  and  it  is  not  produced  with  the  urine  diluted  with  one 
or  two  volumes  of  water.  When  urea  is  present  in  excess,  crystals 
of  urea  nitrate  separate  (p.  582),  but  these  differ  widely  in  appear- 
ance from  the  amorphous  coagulum  of  albumin;  are  formed  through- 
out the  liquid  after  a  short  time;  and  are  not  produced  with  the 
diluted  urine.  Occasionally  the  urine  contains  resinous  substances, 
usually  administered  as  medicines,  which  with  Heller's  test  give  a 
zone  resembling  that  produced  by  albumin.  This  may  be  dis- 
tinguished by  removing  the  portion  of  the  liquid  containing  the  ring 
by  means  of  a  pipette  and  shaking  it  in  another  test-tube  with  a 
little  ether,  when  it  will  clear  if  it  be  resinous,  but  will  remain 
cloudy  if  albuminous.  Sometimes  undiluted  urines  give  no  im- 
mediate reaction,  and  only  a  faint,  ill -defined  ring  after  standing, 


URINE  599 

but  the  diluted  urine  gives  an  immediate  and  well -denned  reaction; 
this  is  caused  by  the  so-called  nucleoalbumen  (p.  603).  True  mucin 
may  also  produce  a  faint  opalescence,  but  no  well-defined  ring,  and 
the  opalescence  disappears  on  slight  rotation  of  the  tube.  The 
primary  albumoses  respond  to  the  Heller  test,  but  they  redissolve  on 
heating  the  test-tube,  and  they  are  not  coagulated  by  heat,  hence 
the  heat  test  should  always  be  used  as  well  as  the  Heller. 

(3)  Precipitation  by  Neutral  Salts. —  Several   tests   are   in   use, 
based  upon   the   precipitation  of   albumin   from  acid   solutions   by 
saturated  solutions  of  neutral  salts,  such  as  sodium  sulfate,  mag- 
nesium sulfate   or  sodium  chlorid.     Roberts'  reagent  consists  of  a 
saturated  solution  of  sodium  chlorid  containing  5  per  cent,  of  strong 
hydrochloric  acid,   and   filtered  if   necessary.     The  urine  is  floated 
upon  the  warmed  reagent  in  the  same  manner  as  in  the  application  of 
Heller's    method ;     and    a   milky   zone    indicates    the    presence   of 
albumin.     Albumoses  are  also  precipitated,  but  not  urates;   nor  does 
the  colored  zone  appear. 

If  acetic  acid  be  added  to  albuminous  urine  to  strongly  acid  reac- 
tion, and  then  an  equal  volume  of  saturated  sodium  sulfate  solution, 
and  the  mixture  boiled,  the  albumin  is  completely  precipitated,  while 
the  albumoses  remain  in  solution  in  the  hot  liquid.  This  reaction, 
designated  as  Panum's  method,  is  utilized  to  free  the  urine  from 
albumen  in  testing  for  albumoses  (p.  602). 

Other  Precipitation  Tests. —  Several  of  the  precipitation  reactions 
of  the  albumens  (p.  502)  have  been  utilized  for  the  detection  of 
albumen  in  the  urine.  Prominent  among  these  are  the  following: 

(4)  Ferrocyanid  Reaction. — Acetic  acid  is  added  to  the  urine  in 
such  amount  as  to  be  present  in  the  proportion  of  2%,  and  then  a 
1:20  solution  of  potassium  ferrocyanid  drop  by  drop  A    A  cloudiness 
or  flaky  precipitate  is  produced  by  serum  albumin,  serum  globulin, 
or  primary  albumoses,  but  the  last  named  are  redissolved  by  addi- 
tion of  much  acetic  acid  and  warming.     The  test  is  quite  as  delicate 
as  the  Heller.     If  the  addition  of  acetic  acid  alone  produce  a  cloud- 
iness, it  is  due  to  the  presence  of  mucin  or  of  mucin -like  substances, 
and  the  urine  is  to  be  filtered  before  addition  of  the  ferrocyanid. 

In  the  following  tests  the  urine  is  to  be  floated  upon  the  surface 
of  the  reagent  in  the  same  manner  as  in  the  application  of  the 
Heller  test,  and  the  characteristic  appearance  is  also  the  formation 
of  a  milky  zone. 

(5)  Trichloracetic  Acid  Reaction. — This  reaction   is   still   more 
delicate  than  the  Heller.     A  strong  solution  of  the  acid  (sp.  gr.= 
1.14)    is  used,  or  a  crystal  of  the  acid  is  dropped  into  the  urine, 
and,  dissolving,  it  forms  a  layer  at  the  bottom.      Serum  albumin, 
serum  globulin  and  primary  albumoses  respond  to  the  test,  but  the 


600  MANUAL    OF    CHEMISTRY 

last-named  redissolve  on  heating,  while  the  others  remain.  Excess 
of  urates  also  gives  rise  to  the  same  appearance  as  with  the  Heller 
reaction,  and,  similarly,  its  formation  is  prevented  by  previous  dilu- 
tion of  the  urine.  The  colored  zone  produced  by  urinary  pigments  in 
the  Heller  test  is  not  formed  with  this  or  with  the  following  reagents. 

(6)  Spiegler's  Reagent  —  consists  of  8  gms.  of  mercuric  chlorid, 
4 gins,  of  tartaric  acid  and  20  cc.  of  glycerol,  dissolved  in  200  cc.  of 
water.     A  few  drops  of  acetic  acid  are  to  be  added  to  the  urine  for 
this  test,  which  is  said  to  be  the  most  delicate  of  those  for  albumin. 
Its  limit  is  placed  at  1:250.000,  and  it  is  frequently  observed  with 
normal  urine.     The  sp.  gr.  of  urines  below  1.005  is  to  be  raised 
by  addition  of  salt  solution  before  application  of  the  test.     Primary 
albumoses  give  the  reaction,  but  secondary  albumoses  (urinary  pep- 
tone) do  not. 

(7)  Tanret's  Reagent  —  is  made  by  dissolving  1.35gm.  of  mer- 
curic chlorid   and   3.32    gms.   of   potassium  iodid   in  separate  por- 
tions of  water,  mixing  the  solutions,  making  the  bulk  up  to  COcc., 
and  adding  20  cc.  of  glacial  acetic  acid.     Secondary  albumoses  are 
also  precipitated,  but  redissolve  on  heating.     Certain  alkaloids  are 
also  precipitated,  but  they  are  dissolved  by  ether  shaken  with  the 
aqueous  liquid,  which  then  becomes  clear.     Several  other  reagents, 
containing    mercuric    salts    (Bouchardat's,   Jolle's,   Zouchlos',  Fur- 
gringer's)  are  in  use. 

(8)  Oliver's  Reagent  is  one  of  several  (Sounenschein's,  Maschke's, 
Jaowrowski's)  containing  tungstates  or  molybdates.     It  is  a  mixture 
of  equal   parts  of   a  20%  solution  of   sodium  tungstate,   and   60% 
solution  of  citric  acid.     It  precipitates  secondary  albumoses,  which, 
however,  dissolve  on  heating,  and  also  alkaloids. 

(9)  Rock's  Reagent,  Salicylsulfonic  acid,  and  (10)  Riegler's  Re- 
agent, /?-naphthol-o-sulfonic  acid  (asaprol),  and  orthophenol-sulfonic 
acid  (aseptol),  are  used  in  the  same  manner  as  trichloracetic  acid. 
They  precipitate  albumoses,  which  redissolve  on  heating. 

(11)  Esbach's  Reagent  —  is  one  of  several  containing  picric  acid. 
It  contains  10  gms.  of  picric  acid  and  20  gms.  of  citric  acid  in  the 
liter.     It  is  mixed  with  or  floated  upon  the  urine.     It  precipitates 
all  proteins,  also  uric  acid,  creatinin  and  certain  alkaloids. 

(12)  Metaphosphoric  Acid  —  is  best  used  in  the  form  of  Blum's 
reagent,  which  consists  of  a  10%  solution  of  the  acid,  to  which  have 
been  added   0.05  gm.   of  manganous  chlorid,   dissolved   in   a   little 
dilute  hydrochloric  acid,  and  a  little  lead  peroxid,  and  the  solution 
filtered.     The  reagent  should  not  be  used  if  it  have  lost  its  pink 
color.     It  precipitates  albumoses  and  uric  acid. 

The  color  reactions  of  the  albumens  (p.  502)  cannot  be  applied 
to  the  urine. 


URINE  601 

*est  for  Globulin. —  Neutralize  the  urine  exactly  with  ammonia, 
filter,  and  add  an  equal  volume  of  neutral,  saturated  solution  of 
ammonium  sulfate:  globulin  separates  as  a  white,  flocculent  precipi- 
tate. Albumin  may  be  tested  for  in  the  filtrate  from  this  precipitate 
by  acidulation  with  acetic  acid  and  heating.  Excess  of  urates  may 
give  rise  to  a  precipitate  in  using  this  test,  but  it  is  only  formed 
after  a  time,  is  not  flocculent,  but  granular,  and  is  not  white,  but 
colored. 

Quantitative  Determination  of  Albumin  and  Globulin. —  The 
only  method  of  determining  the  quantity  of  "albumin"  with  any 
degree  of  accuracy  is  gravimetric.  From  20  to  100  cc.  of  the  clear 
urine  (according  as  the  qualitative  testing  has  indicated  a  large  or 
a  small  quantity  of  albumin)  are  made  up  to  100 cc.  of  liquid  by 
addition  of  water,  if  necessary,  and  slowly  heated.  As  the  boiling 
temperature  is  approached,  2-4  drops  of  dilute  acetic  acid  are  added, 
arid  the  mixture  boiled  for  a  few  minutes,  until  the  coagulated  al- 
bumin has  become  flocculent,  when  it  is  collected  upon  a  weighed 
filter,  washed,  first  with  water  containing  a  little  nitric  acid,  then 
with  boiling  water,  then  with  alcohol,  and  finally  once  or  twice  with 
ether,  dried  at  110°,  and  weighed.  For  accurate  determinations, 
the  filter  and  coagulum  are  burnt  and  moderately  ignited,  the  ash 
weighed,  and  its  weight  subtracted  from  that  of  the  albumen  found. 

Quantitative  Determination  of  Globulin. — One  hundred  cc.  of  the 
clear  urine  are  accurately  neutralized  with  ammonia,  an  equal  volume 
of  a  neutral,  saturated  solution  of  ammonium  sulfate  is  added  and 
the  mixture  allowed  to  stand  for  an  hour,  after  which  the  precip- 
itated globulin  is  collected  upon  a  weighed  filter,  washed  with  one- 
half  saturated  ammonium  sulfate  solution,  dried  at  110°,  extracted 
with  boiling  water,  then  with  alcohol,  and  then  with  ether,  dried 
again  at  110°,  and  weighed.  The  filter  and  contents  are  then  burnt, 
ignited,  cooled  and  weighed,  and  the  weight  of  the  ash  subtracted 
from  the  weight  of  globulin,  plus  ash,  previously  obtained.  To  de- 
termine the  relation  between  albumin  and  globulin  a  determination 
of  albumin  and  globulin,  and  another  of  globulin  alone  are  made, 
as  above  directed;  the  difference  is  the  amount  of  albumin. 

Albumoses  (Peptones). — Substances  similar  to  the  products  of 
the  action  of  digestive  enzymes  upon  proteins  occur  in  the  urine  patho- 
logically. Peptones  in  the  modern  sense,  i.  e.,  not  precipitable  by 
saturation  with  ammonium  sulfate,  do  not  appear  in  the  urine  nor- 
mally or  pathologically.  In  the  condition  designated  as  "peptonuria," 
the  so-called  "urinary  peptone"  consists  principally  of  substances 
closely  resembling,  if  not  identical  with,  the  secondary  albumoses, 
(deutero-albumoses,  p.  518).  Peptonuria  in  this  sense  occurs  in  a 
variety  of  pathological  conditions  :  in  diseases  attended  with  the 


602  MANUAL    OF    CHEMISTRY 

formation  of  large  deposits  of  pus,  in  yellow  atrophy  and  in  abscess 
of  the  liver,  in  certain  intestinal  diseases,  including  typhoid,  in  tuber- 
cular ulceration,  in  scurvy,  pyaemia,  septicaemia,  leukaemia,  in  dis- 
eases of  pregnancy,  in  endocarditis,  in  pneumonia,  in  pleurisy,  in 
diphtheria,  in  suppurative  meningitis,  and  in  certain  forms  of 
poisoning. 

Primary  albumoses,  hetero-albumoses,  have  been  met  with  in  the 
urine  (albumosuria)  only  exceptionally  in  a  few  cases  of  osteo- 
malachia. 

The  presence  of  albumoses  is  best  detected  by  Panum's  method 
(p.  599):  acetic  acid  is  added  to  strongly  acid  reaction  and  then  an 
equal  volume  of  saturated  sodium  sulfate  solution,  and  the  liquid  is 
heated  to  boiling  and  filtered  hot;  albumoses  are  precipitated  before 
the  boiling,  are  redissolved  on  boiling,  and  are  again  precipitated 
from  the  filtrate  on  cooling. 

If  nitric  acid  be  added  to  the  hot  filtrate  from  the  coagulated 
albumin,  produced  by  boiling  a  urine  containing  albumin  and  albu- 
moses, no  immediate  precipitation  occurs,  but  on  cooling  a  white  or 
yellow  precipitate  of  albumose  separates,  which  redissolves  on  heat- 
ing, and  reappears  on  cooling. 

Heteroalbumose  (primary  albumose)  gives  the  above  reactions, 
and  is  further  characterized  by  its  action  with  the  heat  test:  at  a 
temperature  of  about  60°  the  urine  becomes  milky  and  deposits  an 
imperfectly  flocculent,  gummy  material,  which  adheres  to  the  walls 
of  the  beaker,  and  which,  in  an  acid  liquid,  dissolves  on  boiling,  to 
reappear  on  cooling  again. 

For  the  detection  of  small  quantities  of  secondary  albumoses 
(urinary  peptone)  the  method  of  Hofmeister,  although  intricate,  is 
the  most  reliable.  It  consists  in  the  complete  removal  of  albumin 
by  precipitation  with  ferric  chlorid,  the  precipitation  of  the  albumose 
with  phosphotungstic  acid,  the  decomposition  of  the  precipitate,  and 
the  application  of  the  biuret  reaction  to  the  solution  of  albumose. 
The  student  is  referred  to  more  comprehensive  treatises  for  the 
details  of  the  process. 

Mucin-like  Substances.  —  The  urine  sometimes  contains  true 
mucins  and  nucleoproteids,  produced  in  the  urinary  tract  below 
the  kidneys.  The  "nubec-ula"  (p.  566)  which  separates  as  a  deli- 
cate cloud  from  normal  urine  on  standing,  has  for  its  chief  protein 
constituent  a  substance  resembling  ovimucoid  (p.  504),  and  desig- 
nated as  urinary  mucoid.  It  is  a  glycoprpteid,  which  on  heating 
with  dilute  acids,  yields  a  reducing  substance,  but  no  sulfuric  acid 
(see  p.  603).  It  is  soluble  in  dilute  alkaline  solutions,  from  which  it 
is  precipitated  by  acetic  acid,  but  soluble  in  an  excess  of  the  acid.  It 
is  similarly  precipitated  by,  and  soluble  in  excess  of  mineral  acids. 


It  is  not  coagulated  by  heat,  even  in  presence  of  sodium  chlorid  to 
saturation;  but  it  is  precipitated  in  the  cold  by  saturation  with  mag- 
nesium or  ammonium  sulfate. 

The  substance  usually  referred  to  as  nucleoalbumen,  or  as  mucus, 
in  the  urine  consists  of  different  protein -coagulating  substances, 
among  which  are  nucleic  acids,  taurocholic  acid,  especially  in 
icterus,  and  particularly 

Chondroitin-sulfuric  acid,  which  is  present  in  small  amount  in 
normal  urine,  and  is  increased  in  diseases  involving  the  renal  and 
vesical  epithelium,  as  in  acute  and  chronic  nephritis  and  in  cystitis, 
also  in  "functional"  albuminuria,  in  icterus,  and  from  the  action  of 
many  poisons,  notably  of  corrosive  sublimate,  arsenic,  pyrogallic 
acid,  naphthol  and  anilin.  This  substance  exists  in  the  urine,  as 
well  as  in  cartilage,  in  combination  with  albumens  in  the  form  of 
chondroproteids,  or  chondroalbumens,  the  first  products  of  decom- 
position of  which  are  a  protein  and  chondroitin-sulfuric  acid.  The 
latter  is  an  amorphous  substance,  easily  soluble  in  water,  strongly 
acid  in  reaction,  precipitable  from  its  solution  by  alcohol  in  presence 
of  excess  of  salts,  or  by  a  large  amount  of  glacial  acetic  acid,  not 
precipitated  by  dilute  acetic  acid,  mineral  acids,  picric  acid  or  tannin. 
With  albumin  it  forms  a  precipitate,  soluble  in  acids  and  in  alkalies. 
It  is  an  ester -sulf uric  acid  (p.  589),  having  the  composition, 
CigEbeNOisSOsOH,  which  on  heating  with  dilute  acids,  is  decomposed 
into  sulfuric  acid  and  chondroitin,  CisH^NOu,  which  is  a  monobasic 
acid,  itself  decomposed  by  further  heating  with  dilute  nitric  acid 
into  acetic  acid  and  chondrosin,  Ci2H2iNOn,  the  latter  an  amido-acid 
which  reduces  alkaline  solutions  of  copper  salts  on  heating. 

The  chondroproteids  react  with  the  Heller  test,  and  their  presence 
in  excess  is  to  be  suspected  when  the  urine  becomes  cloudy  on  addi- 
tion of  acetic  acid  in  the  cold,  and  gives  a  more  distinct  Heller 
reaction  after  dilution  than  when  undiluted.  To  separate  and 
identify  chondroproteids  a  large  volume  of  urine  is  treated  with 
chloroform  to  prevent  decomposition,  and  submitted  to  dialysis  to 
remove  salts;  acetic  acid  is  then  added  in  the  proportion  of  2  p/m, 
and  the  mixture  allowed  to  stand  until  the  precipitate  settles.  This 
is  then  dissolved  in  the  smallest  quantity  of  dilute  alkali  and  again 
precipitated  with  acetic  acid.  The  precipitate  is  then  heated  on  the 
water -bath  with  5  per  cent,  hydrochloric  acid  and  the  solution 
divided  into  two  parts,  one  of  which  is  tested  for  its  reducing  action  by 
Fehling's  solution,  and  the  other  for  sulfuric  acid  by  barium  chlorid. 

A  histon,  a  phosphorized  protein,  apparently  identical  with 
nucleo-histon,  has  been  met  with  in  the  urine  in  a  case  of  leukaemia, 
and  also  in  cases  of  peritonitis  following  appendicitis,  pneumonia, 
erysipelas  and  scarlatina. 


604  MANUAL    OF    CHEMISTRY 

Haemoglobin. — The  blood  coloring -matter  may  exist  in  the  urine 
in  the  two  conditions  of  haematuria  and  of  haemoglobinuria.  The 
former  is  the  consequence  of  a  haemorrhage  somewhere  in  the 
urinary  tract,  the  latter  of  profound  alteration  in  the  blood,  and 
elimination  of  the  liberated  haemoglobin.  In  the  former  condition 
the  sediment  contains  blood -corpuscles,  and  sometimes  blood -casts 
or  small  clots,  and  albumin  is  present  in  the  urine,  whose  color  is 
bright -red,  reddish -brown,  or  dark -brown.  The  location  of  the 
hemorrhage  cannot  be  determined  by  examination  of  the  urine, 
although  it  may  be  noticed  that,  if  it  is  urethral,  the  last  portions 
of  the  urine  passed  are  free  from  blood;  if  it  is  renal,  blood -casts 
are  usually  found  in  the  sediment,  and,  if  it  is  vesical,  blood -clots 
of  considerable  size  may  be  present. 

Haemoglobinuria,  in  which  the  urine  contains  oxyhaemoglobin  or 
methaemoglobin  in  solution,  with  no  blood -corpuscles,  or  very  few, 
in  the  sediment,  is  most  frequently  the  result  of  poisoning,  as  by 
hydrogen  arsenid,  potassium  chlorate,  pyrogallol  and  naphthol,  but 
it  also  occurs  in  malarial  fevers  in  the  tropics,  and  after  severe 
burns  or  after  transfusion  of  blood.  The  urine  varies  in  color  from 
bright -red  to  dark -brown. 

Tests  for  Blood -pigment. —  (1)  The  urine,  suitably  diluted  if  neces- 
sary, gives  the  spectrum  of  oxyhaBmoglobin,  or  that  of  methaemo- 
globin (p.  547).  (2)  Heller's  test:  the  faintly  acid  urine  is  boiled, 
when  a  dirty  brownish  coagulum  of  albumin,  containing  the  blood- 
pigment,  is  formed.  Sodium  hydroxid  is  added  to  the  hot  liquid, 
which  then  clears,  becomes  greenish  in  thin  layers,  and  on  standing 
deposits  a  red  material  having  greenish  reflections,  which  consists 
of  phosphates  and  haematin.  This  precipitate  may  be  collected  and 
used  for  (3)  Teichmann's  test  (p.  550).  (4)  The  guaiac  reaction: 
the  urine  is  rendered  faintly  acid  if  not  already  so,  and  upon  its 
surface  is  floated  a  mixture  of  equal  parts  of  tincture  of  guaiac 
and  old  oil  of  turpentine.  In  the  presence  of  blood  coloring -matter 
a  white  zone  is  produced,  which  soon  turns  bluish,  greenish,  and 
finally  a  brilliant  blue,  and  on  gently  shaking  the  tube  the  whole 
liquid  is  colored  blue  if  the  quantity  of  pigment  is  sufficient.  In 
the  reagent  ozonic  ether  (ether  containing  hydrogen  peroxid)  may 
be  used  in  place  of  oil  of  turpentine.  Pus  gives  a  similar  color 
with  tincture  of  guaiac  alone. 

Haematoporphyrin,  related  to  urobilin  and  isomeric  with  biliru- 
bin,  is  a  normal  constituent  of  the  urine  in  small  amount,  but  is 
notably  increased  in  amount  in  poisoning  by  sulfonal,  trional  and 
tetronal,  or  even  after  long-continued  medicinal  administration  of 
these  remedies;  also,  in  hepatic  cirrhosis  and  in  croupous  pneumonia. 
Usually  it  colors  the  urine  red,  sometimes  of  a  dark  port -wine  color, 


URINE  605 

but  it  may  be  present  in  considerable  amount  in   urines  which  it 
colors  only  slightly.     It  is  not  accompanied  by  albumin. 

To  test  the  urine  for  haematoporphyrin  100  to  200  cc.  are  precip- 
itated with  10%  sodium  hydroxid  solution;  the  precipitate,  of  phos- 
phates and  coloring -matter,  is  dissolved  in  about  10  cc.  of  alcohol 
acidulated  with  hydrochloric  acid,  and  the  solution  is  examined  with 
the  spectroscope  (p.  551).  If  the  result  be  negative  the  alcoholic 
solution  is  rendered  alkaline  with  ammonium  hydroxid,  the  precip- 
itate dissolved  in  a  little  dilute  acetic  acid,  agitated  with  chloroform, 
and  the  chloroform  solution  again  examined  spectroscopically. 

Biliary  Constituents. —  The  urine  may  contain  the  biliary  salts 
and  pigments  as  a  consequence  of  reabsorption  of  bile,  caused  by 
obstruction  of  the  biliary  ducts,  or  when  the  blood -pressure  in  the 
liver  is  lowered  (hepatogenic  icterus) ;  or  the  biliary  pigments  may 
appear  in  the  urine  in  consequence  of  their  formation  in  the  system 
elsewhere  than  in  the  liver,  as  haematoidin  is  produced  from  the 
blood  coloring- matter  (p.  528),  as  in  pernicious  anaemia,  malaria, 
typhoid,  and  in  poisoning  by  hydrogen  arsenid  (hasmatogenic  icterus). 
Urine  containing  bile  is  golden -yellow  or  greenish -brown  in  color, 
and  the  epithelium  which  it  contains  is  also  dyed  yellow.  It  is 
usually  cloudy,  contains  albumin,  and,  when  shaken,  forms  a  yellow, 
persistent  froth  upon  its  surface. 

The  biliary  salts  are  rarely  tested  for,  because  the  examination  for 
the  equally  characteristic  coloring -matters  is  much  more  easily  con- 
ducted. They  may,  however,  be  detected  by  the  Pettenkofer  reaction, 
if  care  be  had  to  avoid  possible  sources  of  error  from  other  substances 
which  also  respond  to  the  test.  To  this  end  the  urine  is  concen- 
trated, extracted  with  alcohol,  and  the  alcoholic  extract  filtered  and 
freed  from  alcohol  by  evaporation.  The  residue  is  dissolved  in  a 
little  water  and  precipitated  with  lead  acetate  and  ammonia.  The 
lead  precipitate  is  collected,  washed,  extracted  with  boiling  alcohol, 
which  is  filtered  off  hot,  treated  with  a  little  sodium  hydroxid  solution 
and  evaporated  to  dry  ness.  The  residue  is  extracted  with  a  little 
absolute  alcohol,  the  solution  mixed  with  about  ten  volumes  of  per- 
fectly anhydrous  ether,  the  precipitate  collected  on  a  small  filter, 
washed  with  a  little  ether,  dissolved  in  a  small  quantity  of  water  and 
tested  by  the  Pettenkofer  method  as  directed  on  p.  527. 

For  the  detection  of  the  biliary  coloring -matters  the  reactions 
described  on  p.  528  are  used.  The  Gmelin  reaction  may  be  modified 
to  Rosenbach's  method,  which  consists  in  filtering  the  urine  through 
a  small  filter,  and  touching  the  dried  filter  with  a  drop  of  nitroso- 
nitric  acid,  when  the  colors  are  produced  in  rings  about  the  drop. 
This  reaction  is  not  satisfactory  in  dark  urines  containing  excess  of 
indican.  In  using  Haminarsten's  reaction  with  urines  containing 


606  MANUAL    OF    CHEMISTRY 

blood  coloring -matter,  or  very  small  quantities  of  bile  pigments,  a 
preparatory  treatment  is  required,  which  consists  in  adding  barium 
chlorid  to  the  urine,  cen tr if u gating,  pouring  off  the  supernatant 
liquid,  shaking  the  sediment  with  2  cc.  of  the  reagent,  and  centri- 
fugating  again,  when  a  bluish-green  solution  is  obtained.  Smith's 
reaction  may  also  be  used:  float  dilute  tincture  of  iodin  (1:10)  on 
the  urine,  when  the  biliary  pigments  form  a  green  ring  at  the  union 
of  the  two  layers. 

Other  Abnormal  Pigments — Urorosein  is  a  coloring -matter,  not 
present  in  normal  urine,  but  appearing  in  a  variety  of  abnormal  con- 
ditions, as  in  diabetes  mellitus,  chlorosis,  osteomalachia,  nephritis, 
typhoid  fever,  phthisis,  pernicious  anemia,  etc.  It  exists  in  the  urine 
as  a  chromogen,  from  which  it  is  formed  by  the  action  of  acids,  and, 
when  so  liberated,  communicates  a  rose -color  to  the  urine.  It  pro- 
duces the  rose -colored  ring  so  frequently  observed  in  applying  the 
Heller  test  to  the  pathological  urines.  To  demonstrate  its  presence 
10  cc.  of  1:4  sulfuric  acid  are  added  to  50  cc.  of  urine,  which  are 
then  shaken  with  a  few  cc.  of  amylic  alcohol,  and  the  amylic  alcohol 
examined  spectroscopically.  Urorosein  gives  a  spectrum  of  one  band 
between  D  and  E,  and  in  concentrated  solution,  allows  only  the  red 
and  orange  rays  to  pass.  The  color  is  discharged  by  alkalies,  and 
returns  on  addition  of  acids,  it  is  also  discharged  by  agitation  of 
its  acid  solution  with  powdered  zinc,  and  reappears  soon  by  exposure 
to  air. 

Melanin  is  formed  from  melanogen  on  exposure  to  air  of  the  urine 
of  patients  with  melanotic  tumors.  Such  urines  are  normal  in  color 
when  first  voided,  but  become  dark  or  even  black  on  standing.  They 
may  be  distinguished  from  urines  behaving  similarly  from  the  pres- 
ence of  derivatives  of  carbolic  acid,  salol,  etc.,  by  the  facts  that  they 
give  with  bromin- water  precipitates  which,  although  at  first  yellow, 
gradually  change  to  black,  and  that  with  ferric  chlorid  they  give  pre- 
cipitates which  are  at  first  gray,  changing  to  black. 

Alkaptomiria  is  another  rare  condition  in  which  the  urine, 
normally  colored  at  first,  turns  dark  on  standing,  and  which  occurs 
in  individuals  suffering  from  tuberculosis  or  from  cerebral  tumors. 
It  is  due  to  the  presence  of  aromatic  oxyacids,  notably  of  glycosuric 
acid  (pp.  405,  406)  which  on  decomposition  yield  colored  phenolic 
derivatives,  probably  similar  to  those  which  color  the  urine  in 
poisoning  by  phenols  and  diphenols.  Glycosuric  acid  is  also  of 
interest  in  connection  with  the  testing  of  urine  for  sugar  in  dark- 
colored  urines,  because  it  reduces  the  cupric  salts  (Fehling's  test, 
etc.),  although  it  does  not  reduce  those  of  bismuth  (Boettger's  test), 
and  it  does  not  ferment. 

Ehrlich's  Diazo-reaction. — The  urine  in  typhoid  fever  contains  a 


URINE 

substance  which  gives  a  more  or  less  intense  red  color  with  diazo- 
benzene-sulfonic  acid  and  ammonia.  The  reaction,  which  can  be 
obtained  with  typhoid  urine  usually  on  the  fifth  or  sixth  day,  but 
not  later  than  the  twenty -second,  was  at  first  said  to  be  patho- 
gnomonic  of  that  disease,  but  it  is  also  obtained  with  the  urine  of 
acute  pulmonary  phthisis,  in  which,  however,  it  does  not  appear 
before  the  third  week  and  continues  to  the  end,  and  also  in  scarla- 
tina, measles,  smallpox  and  other  acute  febrile  diseases.  The  reagent 
used  is  most  conveniently  kept  in  two  solutions:  (1)  a  saturated 
solution  of  sulfanilic  acid  in  a  mixture  of  50  cc.  of  hydrochloric  acid 
and  950  cc.  of  water;  and  (2)  a  0.5  per  cent,  solution  of  sodium 
nitrite.  When  used  1  cc.  of  (2)  is  added  to  40  cc.  of  (1)  and  the 
mixture  shaken.  Equal  volumes  of  the  urine  and  the  reagent 
are  shaken  together  in  a  test-tube  and  1-2  cc.  of  ammonia  are 
floated  upon  the  surface  of  the  mixture,  when,  in  an  affirmative 
result,  a  red  band  is  formed  at  the  junction  of  the  liquids.  Or  a 
better  method  of  applying  the  test  consists  of  adding  50  cc.  of 
absolute  alcohol  to  10  cc.  of  urine,  filtering,  adding  20  cc.  of  the 
reagent  gradually  from  a  burette  to  30  cc.  of  the  filtrate  in  an  Erlen- 
meyer  flask,  with  agitation  after  each  addition,  and  then  slowly 
adding  ammonia,  when  a  red  color  is  produced,  which  remains  per- 
manent when  the  ammonia  has  been  added  in  excess.  Urines  con- 
taining biliary  pigments  become  very  dark  and  cloudy. 

Glucose  —  is  a  normal  constituent  of  the  urine  in  small  amount, 
and  it  is  only  when  the  quantity  is  increased  to  such  a  proportion 
that  the  sugar  is  detectable  in  the  unconcentrated  urine  by  the  usual 
tests  that  "glycosuria"  is  said  to  exist.  Normally  the  carbohydrates 
taken  with  the  food  and  assimilated  are  oxidized  in  the  system,  and 
their  carbon  and  hydrogen  are  finally  eliminated  as  carbon  dioxid 
and  water,  except  for  the  traces  of  sugar  normally  eliminated  as 
such.  But  there  must  be  a  limit  to  the  amount  of  carbohydrate 
material  which  can  be  utilized  by  the  economy  in  a  given  time. 
This  limit  appears  to  vary  in  different  individuals,  but  may  be 
placed  at  an  amount  of  carbohydrate  equivalent  to  100  to  200  gms.  of 
glucose  in  24  hours,  and  probably  when  glycosuria  exists  with  a  daily 
ingestion  of  100  gms.  or  less  of  glucose -equivalent  it  is  due  to  a 
pathological  condition. 

Non- pathological  glycosuria  may  be  observed:  (1)  with  a  diet 
containing  more  than  200  gms.  of  glucose -equivalent  in  twenty -four 
hours.  A  pathological  alimentary  glycosuria  occurs  with  less  than 
100  gms.  glucose -equivalent  in  hepatic  and  pancreatic  disease  and  in 
certain  cerebral  diseases;  (2)  in  pregnancy  and  during  lactation  there 
is  apparently  a  diminution  in  the  power  to  utilize  carbohydrate 
material,  and  glycosuria  frequently  exists  with  a  diet  containing  less 


608  MANUAL    OF    CHEMISTRY 

than  100  gms.  of  glucose -equivalent  in  24  hours,  the  daily  elimina- 
tion sometimes  rising  as  high  as  30  gms.,  but  being  more  usually 
less  than  3  gms.  It  appears  towards  the  end  of  gestation,  and  does 
not  disappear  entirely  until  the  suppression  of  the  lacteal  secretion; 

(3)  in  nursing  children  from  about  the  eighth  day  to  ten  weeks; 

(4)  in  old  persons  (70  to  80  years);    (5)  in  extremely  stout  persons, 
particularly  in  females  at  the  menopause,  the  elimination  sometimes 
reaching  8  to  12  gms.  in  24  hours. 

Pathological,  glycosurias  may  be  divided  into  "transitory,"  in 
which  the  quantity  of  sugar  is  not  large,  and  its  presence  not  con- 
stant; and  "permanent,"  in  which  sugar  is  constantly  present  and 
frequently  in  very  large  amount.  Transitory  glycosuria  occurs  in 
certain  hepatic  derangements,  congestion,  cirrhosis  and  amyloid 
degeneration;  in  many  diseases  of  the  central  nervous  system,  with 
tumors  or  haemorrhages  at  the  base  of  the  brain,  in  meningitis, 
concussion,  fracture  of  cervical  vertebrae,  railway  injuries,  in 
epileptic  and  apoplectic  seizures,  and  also  in  certain  diseases  of 
the  peripheral  nervous  system,  as  in  sciatica  and  in  tetanus;  in  acute 
febrile  diseases,  pneumonia,  typhoid,  acute  articular  rheumatism, 
scarlatina,  etc.,  particularly  during  convalescence,  when  the  elimina- 
tion may  reach  5  to  50  gms.  in  24  hours;  under  the  influence  of 
many  poisons,  such  as  curare,  chloral,  carbon  monoxid,  morphin, 
arsenic,  and  the  anaesthetics. 

Persistent  pathological  glycosuria  is  observed  principally  in  two 
conditions:  (1)  In  lesions  of  the  brain  involving  the  floor  of  the 
fourth  ventricle;  (2)  in  diabetes  mellitus.  In  this  latter  condition 
the  sugar  may  temporarily  disappear  from  the  urine,  particularly  in 
the  earlier  stages  of  the  disease,  in  the  early  morning  urine,  and 
upon  regulation  of  the  diet  by  exclusion  of  carbohydrates.  There  is 
a  diurnal  variation  in  the  elimination  of  sugar,  the  amount  passed 
being  less  during  the  night  than  during  the  day,  the  maximum  being 
reached  about  four  hours  after  the  principal  meal,  and  the  minimum 
six  or  seven  hours  thereafter.  There  is  great  polyuria,  the  quantity 
of  urine  in  24  hours  reaching  as  high  as  50  liters.  The  quantity  of 
sugar  varies  greatly;  an  elimination  of  200  gms.  in  24  hours  is  by 
no  means  uncommon,  but,  even  with  this  large  amount,  the  elimi- 
nation may  cease  entirely,  particularly  in  the  morning  urine,  by 
exclusion  of  carbohydrates  from  the  diet,  under  the  influence  of 
intercurrent  diseases,  or  in  the  later  stages,  upon  the  appearance  of 
diabetic  coma.  Instances  have  occasionally  been  reported  in  which 
the  elimination  has  reached  400  to  600  gms.  in  24  hours,  and  one 
instance  in  which  1376  gms.  were  discharged  in  one  day.  In  other 
severe  cases,  terminating  fatally,  the  quantity  of  sugar  eliminated 
has  not  been  large  at  any  time,  not  exceeding  10  gms.  in  24  hours. 


UEINE  609 

The  non- disappearance  of  the  sugar  from  the  urine  on  exclusion  of 
carbohydrates  from  the  diet  is  usually  considered  as  indicating  a 
more  serious  condition,  even  if  the  quantity  be  small,  than  the 
elimination  of  a  large  amount  which  ceases  under  those  circum- 
stances. The  specific  gravity  of  diabetic  urine  is  usually  high,  1030 
to  1060,  but  it  may  be  as  low  as  1012.  In  true  diabetes  there  is  not 
only  glycosuria.  but  also  azoturia,  and  the  increase  in  the  elimination 
of  nitrogen  appears  to  offer  a  better  measure  of  the  intensity  of  the 
disturbance  than  variations  in  the  amount  of  sugar.  In  the  later 
stages  acetone,  fatty  acids  and  fats  also  appear  in  the  urine  (see 
below) . 

As  has  been  already  indicated  (p.  559),  glycosurias  other  than 
those  due  to  nervous  lesions  may  have  their  origin  in  an  inability  of 
the  liver  to  transform  the  carbohydrates  into  glycogen,  or  to  inability 
of  the  muscles  to  utilize  the  carbohydrate  material,  or  to  diseases  of 
the  pancreas. 

Tests  for  Glucose. —  If  the  urine  be  albuminous,  it  is  indispen- 
sable that  the  albumin  be  separated  before  any  of  the  tests  for 
sugar  are  applied.  This  is  done  by  heating  the  urine  gradually  to 
boiling,  with  addition  of  very  dilute  acetic  acid  as  the  boiling  tem- 
perature is  approached,  and  heating  until  the  albumin  has  separated 
in  flocks,  and  filtering.  The  most  commonly  used  of  the  tests  for 
glucose  depend  upon  its  reducing  power,  and  the  existence  of  other 
reducing  substances  possibly  present  in  the  urine,  referred  to  above, 
must  be  held  in  mind.  In  doubtful  cases  the  phenyl-hydrazin  and 
fermentation  tests,  which  are  not  based  upon  the  reducing  action 
of  glucose,  should  be  resorted  to. 

(1)  Moore's   Test  —  is   more  delicate  with  colorless   solutions  of 
glucose  than  with  the  urine.     Two  samples  of  the  urine  are  taken 
in  two  test-tubes  of  equal  size;  to  one  sufficient  KHO  solution  is 
added  to  make  it  strongly  alkaline,  and  to  the  other  an  equal  vol- 
ume  of   water.     The   alkaline  urine   is   then   heated,  when,  in  the 
presence  of  sugar,  it  becomes  more  deeply  yellow  or  brown  in  color, 
and,  on  addition  of   HN03,   gives   off   a   molasses -like   odor.     The 
second  tube  is  used  for  comparison. 

(2)  Trommer's   Test.  —  To   the  urine,   in   a   test-tube,  add   one- 
eighth  its  bulk  of  KHO  or  NaHO  solution,  and  then  5%  solution 
of  CuS04  in  slight  excess,  until  the  pale -blue  precipitate,  which  is 
at  first  redissolved,  remains  permanent.     The  liquid  is  then  heated 
just   to  boiling,   but   not   boiled,  when  a  yellow  or  orange -colored 
precipitate  of  cuprous  hydroxid  or  oxid  is  formed  if  sugar  be  pres- 
ent.    Although  very  generally  used  by  clinicians,  and  giving  good 
results  when  the  quantity  of  sugar  present  is  notable  but  not  very 
large,   this  test   is  open  to  several   objections:    if   the  quantity  of 

39 


610  MANUAL    OP    CHEMISTRY 

sugar  be  large  and  a  little  copper  solution  be  added,  the  liquid  will 
become  yellow  without  depositing  any  precipitate,  the  cuprous  oxid 
formed  being  held  in  solution  by  the  excess  of  glucose.  If  too  much 
copper  salt  be  added  the  precipitate  may  be  black  or  brown  (cupric 
oxid)  in  place  of  yellow  or  reddish.  If  the  quantity  of  sugar  be  very 
small  there  is  no  reduction,  except  upon  prolonged  boiling,  when 
reduction  is  also  caused  by  uric  acid,  creatinin,  etc.  Reduction  is 
also  caused  by  diphenols,  milk  sugar,  benzoic  acid,  salicylic  acid, 
glycerol,  chloral,  sulfonal,  and  biliary  pigments.  Limit — 0.0025%. 

(3)  Fehling's  Test. — A  good  formula  for  this  reagent,  which  is  also 
used  for  quantitative  determinations,  is:   Soln.  I,  cupric  sulfate  51.98 
gms.,  water  500  cc.     Soln.  II,  Rochelle  salt  259.9  gms.  dissolved  in 
1000   cc.    of    a   solution    of    caustic   soda   of    sp.   gr.   1.12.     When 
required  for  use  1  volume  of   Soln.  I  is  mixed  with  2  volumes  of 
Soln.  II;   2  cc.  of  the  mixture  are  heated  in  a  test-tube  just  to  boil- 
ing and  then  transferred  to  another  test-tube.     If  any  reddish  pre- 
cipitate   be    found    adherent    to    the    first    tube    the    solution    has 
deteriorated  and  should  not  be  used.     This  is  to  be  expected  when 
the  two  solutions  have  not  been  mixed  shortly  before  using.     The 
urine  is  now  gradually  added  to  the  solution,  which  is  raised  to  the 
boiling  point  after  each  addition.     The  presence  of  sugar  is  indicated 
by  the  formation  of  a  reddish  precipitate,  which  forms  more  or  less 
rapidly  according  to  the  proportion  present;  the  result  is  considered 
as  negative  when  a  volume  of  urine  equal  to  that  of  the  solution 
used   has   been    added  without   the   formation   of  such   precipitate. 
Fehling's  test  is  not  open  to  the  first  two  objections  to  Trommer's 
test  mentioned  above,  but  it  reacts  with  the  substances  there  referred 
to.     Limit— 0.0008%. 

(4)  Boettger's  Test — is  also  a  reduction  test,  and  may  be  applied 
either  in  the  manner  originally  indicated  or  in  Nylander's  or  Almen's 
modifications.     Equal  portions  of  urine  are  placed  in  two  test-tubes, 
to  each  of  which  enough  solution  of  sodium  carbonate  is  added  to 
make  the  reaction  distinctly  alkaline,  and  to  one  a  little  powdered 
bismuth  subnitrate  and  to  the  other  a  little  powdered  litharge  are 
added.     The  contents  of  the  two  tubes  are  then  heated  to  boiling, 
when,  if  the  bismuth  powder  becomes  black  and  the  litharge  remains 
unchanged  the  presence  of  sugar  is  inferred.     The  purpose  of  the 
litharge  is  to  guard  against  error  from  the  presence  of  sulfur  com- 
pounds,   which    blacken    both     the     bismuth    and    lead     powders. 
Nylander's  solution  is  made  by  adding  4  gms.  of  Rochelle  salt,  2 
gms.  of  bismuth  subnitrate  and  10  gms.  of  caustic  soda  to  90  cc.  of 
water,  boiling,  cooling  and  filtering.     The  solution  is  to  be  kept  in 
bottles  of  amber  glass.    To  use  the  test  1  cc.  of  the  solution  is  added 
to  10  cc.  of  the  urine  and  the  mixture  boiled,  when  sugar  causes  the 


I 


URINE  611 


formation  of  a  gray  or  black  precipitate.  A  parallel  testing  with 
litharge  is  also  required.  An  affirmative  result  is  obtained  in  the 
absence  of  sugar  after  large  doses  of  quinin,  but  uric  acid  and 
creatinin  do  not  react.  Limit — 0.025%. 

(5)  Fermentation    Test. —  Three   Smith's  fermentation -tubes  are 
used,  one    (A)  completely  filled  with  water,  one    (B)  with  a  dilute 
solution  of  glucose,  and  the  third  (C)  with  the  urine  to  be  tested, 
and  each  containing  a  little  compressed  yeast.     The  three  tubes  are 
put  in  warm  place  and  left  over -night,  when  if  gas  have  collected  in 
B  and  C  and  none  in  A  the  urine  contains  sugar;   if  gas  have  col- 
lected in  B,  but  none  in  A  or  C  it  is  absent;   under  any  other  circum- 
stances the  yeast  is  at  fault.     The  only  substances  other  than  glucose 
which  respond  to  this  test  are  the  other  fermentable  carbohydrates, 
lactose,  maltose  and  fructose. 

(6)  Phenylhydrazin  Test — depends  upon  the  formation  of  the  crys- 
talline glucosazone  (p.  430).     To  5  cc.  of  the  urine  in  a  test-tube 
add  as  much  phenylhydrazin  hydrochlorid  as  can  be  taken  on  the 
point  of  the  large  blade  of  a  pen -knife,  and  about  1%  times  that  bulk 
of  sodium  acetate,  and  cause  the  powders  to  dissolve  by  warming  and, 
if  necessary,  the  addition  of   water,   and  leave  the  test-tube  in  a 
boiling  water -bath  for  one  hour,  after  which  cool  it  by  immersion  in 
a  beaker  of  cold  water.     If  glucose  be  present  a  deposit  of  yellow 
needles  will  be  formed,  which,  if  the  quantity  of  sugar  be  small,  are 
best  detected  by  allowing  the  deposit  to  settle  in  a  pointed  tube  and 
examining   it   with  the  microscope.     The    formation   of   crystalline 
plates,  or  of  brown,  nodular  masses  does  not  indicate  the  presence  of 
glucose.     Needle-shaped  crystals  are  also  formed  by  maltose  and  by 
glucuronic  acid,  but  they  differ  from  those  produced  by  glucose  in 
their  fusing  points  :  glucose  =205°,  maltose  =190°,  glucuronic  acid 
=115°.     To  determine  the  fusing  points  the  precipitate  is  collected, 
dissolved  in  hot  alcohol,  the  solution  filtered,  and  evaporated,   the 
crystals  dried  over  H2SO4,  placed  in  a  small  closed  tube  attached  to 
the  bulb  of  a  thermometer  by  a  pasted  slip  of  paper,  and  heated  in  a 
paraffin  bath,  the  temperature  being  noted  when  the  material  fuses. 

(7)  Polarization   Test. — Preparatory  to  polariscopic  examination 
he  liquid  must  be  rendered  transparent  and  colorless,  or  nearly  so. 

This  is  accomplished  in  the  case  of  the  urine  and  other  organic 
liquids  by  isolation  of  the  sugar,  by  precipitation  either  by  basic  lead 
acetate,  or  by  benzoyl  chlorid,  liberation  of  the  sugar  and  resolution 
in  water.  Either  operation  is  rather  intricate,  and  the  student  is 
referred  to  more  comprehensive  treatises  for  their  description .  The 
decolorized  solution  is  examined  with  the  polarimeter  (p.  24),  and  if 
glucose  be  present  it  will  rotate  to  the  right.  Maltose  also  rotates  to 
the  right.  Oxybutyric  acid  (p.  615)  rotates  to  the  left,  and  if  it  be 


612  MANUAL    OF    CHEMISTRY 

present  in  notable  quantity,  may  neutralize  or  dominate  the  right- 
handed  rotation  of  the  glucose.  But  such  urines  show  a  greater 
left-handed  polarization  after  fermentation  than  before. 

For  clinical  purposes  the  Fehling  or  Boettger  tests  are  to  be 
recommended,  supplemented  by  the  fermentation  or  phenylhydrazin 
test  in  cases  of  doubt. 

Quantitative  Determination  of  Glucose. —  (1)  By  the  polctrimeter. 
— Clear,  decolorized  urine  (see  above)  is  observed  by  the  polarimeter 
(p.  24)  and  the  mean  of  half  a  dozen  readings  taken  as  the  angle  of 
deviation.  From  this  the  percentage  of  sugar  is  determined  by  the 

formula  p=^6y,l,  in  which  p  =  the  weight,  in  grams,  of  glucose 

in  1  cc.  of  urine;  a  =  the  angle  of  deviation;  /  =  the  length  of  the 
tube  in  decimeters.  The  same  formula  may  be  used  for  other  sub- 
stances by  substituting  for  52.6  the  value  of  [a]D  for  that  substance. 
Or  a  saccharrimeter,  which  is  a  polarimeter  graduated  to  read  the 
percentage  of  glucose  directly,  may  be  used.  If  the  urine  contain 
albumen,  it  must  be  removed  befere  determining  the  value  of  a. 

(2)  By  specific  gravity  ;  Robert's  method. — The   sp.   gr.    of   the 
urine  is  carefully  determined  at  25°  (77°  F.);  yeast  is  then  added, 
and  the  mixture  kept  at  25°  (77°  F.)  until  fermentation  is  complete; 
the  sp.  gr.  is  again  observed,  and  will  be  found  to  be  lower  than 
before.     Each  degree  of  diminution  represents  0.2196  gram  of  sugar 
in  100  cc.  of  urine. 

(3)  By  Fehling7 s  solution. — The  copper  contained  in  20  cc.   of 
Fehling's  solution  (p.  610)  is  precipitated  by  0.1  gm.  of  glucose. 

To  use  the  solution,  20  cc.  of  the  mixed  solutions  are  placed  in  a 
flask  of  250-300  cc.  capacity,  80  cc.  of  distilled  water  are  added,  the 
whole  thoroughly  mixed  and  heated  to  boiling.  On  the  other  hand, 
the  urine  to  be  tested  is  diluted  with  four  times  its  volume  of  water 
if  poor  in  sugar,  and  with  nine  times  its  volume  if  highly  saccharine 
(the  degree  of  dilution  required  is,  with  a  little  practice,  determined 
by  the  appearance  of  the  deposit  obtained  in  the  qualitative  testing) ; 
the  water  and  urine  are  thoroughly  mixed  and  a  burette  filled  with  the 
mixture.  A  little  CaC^  solution  is  added  to  the  Fehling's  solution 
and  the  diluted  urine  added,  in  small  portions  toward  the  end,  until 
the  blue  color  is  entirely  discharged  —  the  contents  of  the  flask  being 
made  to  boil  briskly  between  additions  from  the  burette.  When 
the  liquid  in  the  flask  shows  no  blue  color  when  looked  through  with 
a  white  background  in  daylight  the  reading  of  the  burette  is  taken. 
This  reading,  divided  by  five  if  the  urine  was  diluted  with  four  vol- 
umes of  water,  or  by  ten  if  with  nine  volumes,  gives  the  number  of 
cc.  of  urine  containing  0.1  gram  of  glucose;  and  consequently  the 
elimination  of  glucose  in  24  hours,  in  decigrams,  is  obtained  by 


URINE  613 

dividing  the  number  of  cc.  of  urine  in  24  hours  by  the  result  ob- 
tained above. 

Example. — 20  cc.  Fehling's  solution  used,  and  urine  diluted  with 
four  volumes  of  water. 

Reading  of  burette:  36.5  cc.~5-=7.3  cc.  urine  contain  0.1  gram 

glucose.     Patient  is  passing  2,436  cc.  urine  in  21  hours.  -yg-^333.6 

decigr.  =33.36  grams  glucose  in  24  hours. 

The  accuracy  of  tire  determination  may  be  controlled  by  filtering 
oif  some  of  the  fluid  from  the  flask  at  the  end  of  the  reaction ;  a  por- 
tion of  the  filtrate  is  acidulated  with  acetic  acid  and  treated  with  po- 
tassium ferrocyanid  solution.  If  it  turns  reddish -brown  the  reduction 
has  not  been  complete,  and  the  result  is  affected  with  a  plus  error. 
To  another  portion  of  the  filtrate  a  few  drops  of  cupric  sulfate  solu- 
tion are  added  and  the  mixture  boiled;  if  any  precipitation  of  cuprous 
oxid  be  observed,  an  excess  of  urine  has  been  added,  and  the  result 
obtained  is  less  than  the  true  one.  But  if  the  urine  contains  a  large 
amount  of  urea  this  is  decomposed  with  formation  of  ammonia,  which 
dissolves  a  portion  of  the  cupric  oxid,  carrying  it  through  the  filter. 

This  method,  when  carefully  conducted  with  accurately  prepared 
and  undeteriorated  solutions,  is  well  adapted  to  clinical  uses.  The 
copper  solution  should  be  kept  in  the  dark,  in  a  well -closed  bottle, 
and  the  No.  II  bottle  should  be  closed  with  a  rubber  stopper.  The 
results  of  the  process  are  only  accurate  when  the  saccharine  liquid 
contains  less  than  1%  of  glucose,  and  if  the  Fehling's  solution  is 
used  in  the  dilution  given  above. 

(4)  Gravimetric  method. — When  more  accurate  results  than  are 
obtainable  by  Fehling's  volumetric  process  are  desired,  recourse 
must  be  had  to  a  determination  of  the  weight  of,  cuprous  oxid  ob- 
tained by  reduction.  A  small  quantity  of  freshly  prepared  Fehling's 
solution,  diluted  with  four  times  its  volume  of  boiled  water,  is 
heated  to  boiling  in  a  small  flask.  To  it  is  gradually  added,  with 
the  precautions  observed  in  the  volumetric  method,  a  known  volume 
of  the  diluted  urine,  such  that  at  the  end  of  the  reduction  there  shall 
remain  an  excess  of  unreduced  copper  salt.  The  alkaline  fluid  is 
separated  as  rapidly  as  possible  from  the  precipitated  oxid,  by  decan- 
tation  and  filtration  through  a  small  double  filter,  and  the  precipi- 
tate and  flask  repeatedly  washed  with  hot  HoO  until  the  washings  are 
no  longer  alkaline.  A  small  portion  of  the  precipitate  remains  adher- 
ing to  the  walls  of  the  flask.  The  filter  and  its  contents  are  dried 
and  burned  in  a  weighed  porcelain  crucible.  When  this  has  cooled, 
the  flask  is  rinsed  out  with  a  small  quantity  of  HNOs;  which  is  added 
to  the  contents  of  the  crucible,  evaporated  over  the  water -bath,  the 
crucible  slowly  heated  to  redness,  cooled,  and  weighed.  The  differ- 


614  MANUAL    OF    CHEMISTRY 

ence  between  this  last  weight  and  that  of  the  crucible  +  that  of  the 
filter-ash,  is  the  weight  of  cupric  oxid,  of  which  220  parts  =100 
parts  of  glucose.  Or  better,  the  cupric  oxid  is  dissolved  in  a  little 
dilute  nitric  acid,  the  solution  evaporated  with  a  little  sulfuric  acid, 
the  residue  redissolved,  and  the  copper  determined  electroly tically : 
175.6  Cu.  =  100  glucose. 

(5)  Knapp's  Method.  —  Several  methods  have  been  su-ggested, 
based  upon  the  reduction  of  the  salts  of  mercury.  The  oldest  of 
these  depends  upon  the  reduction  of  mercuric  cyanid  by  glucose. 
The  standard  solution  consists  of  10  gms.  of  pure,  crystallized  mer- 
curic cyanid  and  100  cc.  of  a  solution  of  sodium  hydroxid,  sp.  gr. 
1.145  in  a  litre.  Twenty  cc.  of  this  solution  are  reduced  by  0.05gm. 
of  glucose.  The  solution  is  used  in  the  same  way  as  Fehling's  solu- 
tion: 20 cc.  of  the  solution  are  diluted  with  80  cc.  of  water  and 
heated  in  a  flask  to  boiling.  The  urine,  diluted  with  water  in  the 
proportion  of  1:4  or  of  1:9,  is  added  from  a  burette,  at  first  in 
portions  of  2cc.,  then  of  Ice.,  then  of  0.5cc.  and  finally  of  O.lcc. 
As  the  end  reaction  is  approached,  the  liquid  clears,  and  the  mercury 
deposits.  A  drop  of  liquid  is  then  removed  from  time  to  time  with  a 
capillary  tube,  placed  upon  a  piece  of  filter  paper,  and  held,  first  over 
a  bottle  containing  strong  hydrochloric  acid,  then  over  one  contain- 
ing a  strong  solution  of  hydrogen  sulfid,  until  it  no  longer  assumes 
a  yellow  or  brown  color.  The  calculation  is  the  same  as  with  Feh- 
ling's  solution,  and  the  result  is  multiplied  by  two.  The  end  reaction 
is  somewhat  sharper  than  that  of  Fehling's  solution,  and  daylight 
is  not  required. 

Other  Sugars  —  Lcevulose  (fructose) — sometimes  occurs  in  dia- 
betic urine.  When  it  is  present  the  urine  responds  to  the  tests 
for  glucose,  but  it  either  rotates  to  the  left  or  has  a  dextrogyratory 
action  less  than  that  required  by  the  result  of  the  quantitative  re- 
duction methods. 

Lactose  occurs  in  the  urine  after  the  ingestion  of  large  quantities 
of  milk-sugar,  and  sometimes  in  the  urine  of  women  during  the  later 
stages  of  gestation  and  during  lactation.  Its  presence  may  be  in- 
ferred when  the  urine  reacts  with  the  copper  and  bismuth  tests, 
but  gives  negative  results  with  the  fermentation  test. 

Maltose  rarely  acompanies  glucose  in  pancreatic  diabetes. 

Laiose  is  a  substance  which  occurs  in  the  urine  in  some  cases 
of  diabetes.  It  is  Ia3vogyrous  and  amorphous,  it  reduces  the  com- 
pounds of  copper  and  of  bismuth,  does  not  ferment,  and  forms  a 
yellow  or  brown  oily  material  with  phenylhydrazin.  It  is  supposed 
to  be  a  sugar. 

Pentoses  (p.  264)  have  been  met  with  in  large  amount  in  the 
urine  of  persons  addicted  to  the  morphin  habit,  in  whom  there  is 


URINE  615 

an  alternation  of  glycosuria  and  pentosuria.  The  pentoses  are  de- 
tected by  Tollens'  reaction :  the  urine  is  mixed  with  an  equal  volume 
of  strong  hydrochloric  acid,  a  little  phloroglucin  is  added,  and  the 
liquid  heated  by  immersion  in  a  boiling  water -bath.  A  red -violet 
color  indicates  the  presence  of  pentoses,  galactose,  lactose,  or  glucu- 
ronic  acid.  To  distinguish  between  these  the  liquid  is  examined  with 
the  spectroscope,  when,  in  the  presence  of  pentoses  or  of  glucuronic 
acid,  a  band  is  seen  in  the  green,  between  D  and  E.  The  pentoses 
and  glucuronic  acid  may  be  distinguished  by  the  fusing  points  of 
their  osazones,  that  of  glucuronic  acid  fusing  at  115°,  and  those 
of  the  pentoses  at  a  higher  temperature,  160°. 

Inosite,  muscle  sugar,  is  a  cyclic  alcohol,  CeB^OHje,  which 
occurs  in  traces  in  normal  urine,  and  in  increased  amount  in  albu- 
minuria,  in  diabetes  insipidus,  and  after  ingestion  of  large  quantities 
of  water. 

Acetone  —  is  a  normal  constituent  of  the  urine  in  the  proportion 
of  about  O.Olgm.  in  24  hours,  and  is  a  product  of  the  metabolism 
of  the  proteins.  In  the  normal  system  this  amount  may  be  increased 
to  0.7  in  24  hours  by  exclusion  of  carbohydrates  from  the  diet,  when 
acetyl- acetic  acid  also  appears  in  the  urine.  A  similar  increase  also 
occurs  during  starvation.  This  increased  elimination  is  immediately 
arrested  by  supplying  carbohydrates,  but  not  with  addition  of  fats 
to  the  diet,  which,  on  the  contrary,  produce  a  further  increase. 
Acetonuria  also  occurs  in  pathological  conditions  involving  increased 
protein  metabolism,  as  in  febrile  diseases  when  the  febrile  condition 
is  prolonged,  but  not  when  it  is  of  short  duration;  also  in  certain 
mental  diseases,  general  paresis,  melancholia,  epilepsy;  and  also  after 
chloroform  narcosis.  When  acetonuria  exists,  acetone  is  also  elim- 
inated by  the  lungs,  and  communicates  a  peculiar,  sweet,  apple -like 
odor  to  the  breath.  The  acetonuria  of  diabetes  mellitus  is  most 
significant,  for,  not  only  does  the  simultaneous  occurrence  of  glucose 
and  of  acetone  in  the  urine  render  the  diagnosis  of  diabetes  certain, 
but  the  amount  of  the  latter,  which  may  reach  5gms.  in  24  hours, 
is  directly  proportionate  to  the  intensity  of  the  disease.  The  in- 
creased elimination  of  acetone  is  also  in  part  due  to  the  exclusion 
of  carbohydrates  from  the  diet  of  the  diabetic,  and  both  acetone 
and  threatening  symptoms  disappear  sometimes  on  addition  of  car- 
bohydrates, to  the  extent  of  50  to  100  gms.  of  glucose -equivalent 
in  24  hours,  to  the  diet. 

Probably  acetone  is  not  of  itself  actively  poisonous,  and  the 
serious  symptoms  of  the  later  stages  of  diabetes  sometimes  ascribed 
to  it  are  really  symptoms  of  "acidism"  caused  by  the  presence  in 
the  blood  of  acetyl -acetic  acid  and  /3-oxybutyric  acid,  which  always 
accompany  the  acetone,  and  possibly  of  other  acids  as  well.  The 


616  MANUAL    OP    CHEMISTRY 

chemical  relationship  of  these  three  substances  is  quite  close,  as  is 
shown  by  their  formulae:  acetone  =  CH3. CO. CH3;  acetyl- acetic  acid 
=  CH3.CO.CH2.COOH,  and  0-oxybutyric  acid  =CH3.CHOH.CH2.- 
COOH. 

Tests  for  Acetone. — As  acetyl -acetic  acid  is  decomposed,  with 
formation  of  acetone,  by  simple  heating  of  the  nriner  this  must  first 
be  tested  for  by  QerhardVs  test:  Add  dilute  solution  of  neutral 
ferric  chlorid  so  long  as  a  precipitate  (of  phosphates)  is  formed, 
filter,  and  add  more  ferric  chlorid  solution,  a  wine  red  color  is  pro- 
duced if  acetyl -acetic  acid  be  present.  If  the  result  be  affirmative  it 
should  be  confirmed  by:  (1)  Render  a  portion  of  the  urine  faintly 
acid,  boil,  cool,  and  repeat  the  test,  which  should  give  a  negative 
result;  (2)  acidulate  another  portion  with  dilute  sulfuric  acid,  agitate 
with  ether,  and  then  agitate  the  separated  ether  with  dilute  ferric 
chlorid  solution,  which  should  be  colored  wine -red.  If  there  be  no 
acetyl  -  acetic  acid  present  the  urine  is  tested  for  acetone  as  directed 
below,  but  if  it  be  present  the  urine  is  rendered  faintly  alkaline, 
agitated  in  a  separator  with  a  mixture  of  alcohol  and  ether,  the 
ether  separated,  agitated  with  water,  and  the  water  tested  for  acetone 
by  the  tests  given  below.  In  the  absence  of  acetyl -acetic  acid  a  liter 
of  the  urine  is  acidulated  by  addition  of  1  gm.  of  phosphoric  acid, 
and  distilled;  30  cc.  of  distillate  being  collected  and  tested  by: 

(1)  Lieben's  Iodoform  Test. — Add  caustic  soda  and  a  little  solu- 
tion of  iodin  in  potassium  iodid,  and  warm:   the  odor  of  iodoform  is 
produced,  and  a  yellow,   crystalline  precipitate,   if  the  quantity  be 
sufficient.     Also  reacts  with  alcohol.     Or  Gunning's  modification  of 
this  test,  which  has  the  advantage  of  not  reacting  with  alcohol  or 
aldehyde,  may  be  used:    An  alcoholic  solution  of  iodin  and  ammonia 
are  used  in  place  of  the  aqueous  iodin  solution,  which  causes   the 
formation  from  acetone  of  iodoform  and  the  black  nitrogen  iodid, 
which  latter  gradually  disappears  on  standing,  leaving  the  iodoform. 

(2)  LegaVs  Nitroprussid  Test. — Add  a  few  drops  of  a  freshly  pre- 
pared  solution   of   sodium   nitroprussid,    and   then  KHO  or  NaHO 
solution,  when,  in  presence  of  acetone,  the  liquid  is  colored  ruby- 
red,   and,  on  supersaturation  with   acetic  acid,   changes  to  purple. 
Paracresol  gives  a  yellow -red  color,  which  changes  to  yellow  with 
excess  of  acetic  acid.     Creatinin  gives  an  initial  color  with  this  test 
similar  to  that  produced  by  acetone,  but  on  addition  of  acetic  acid, 
it  turns  to  yellow,  and  slowly  to  green  or  blue.     But  creatinin  can- 
not be  the  source  of  error  if  the  urine  has  been  distilled  as  above 
directed. 

(3)  Reynold's  Mercuric  Oxid  Test — is  based  upon  the  property  of 
acetone  to  dissolve  freshly  precipitated  mercuric  oxid.     Mercuric  oxid 
is  precipitated  from  a  solution  of  mercuric  chlorid  by  addition  of  an 


URINE 


617 


alcoholic  solution  of  potassium  hydroxid,  and  a  portion  of  the  distil- 
late is  added  to  the  mixture,  which  is  then  strongly  shaken  and 
filtered.  The  formation  of  a  black  precipitate  by  addition  of 
ammonium  sulfid  to  the  filtrate  indicates  that  it  contains  dissolved 
mercuric  oxid. 

(4)  PenzolcVs  Indigo  Test. — Add  a  portion  of  the  distillate,  and 
then  NaHO  solution  to  solution  of  orthonitrobenzaldehyde,  -pre- 
pared by  making  a  hot  saturated  solution  and  cooling  it,  when,  in 
presence  of  acetone,  the  liquid  turns  yellow,  then  green,  and  finally 
deposits  indigo -blue.  If  chloroform  be  then  shaken  with  the 
mixture  it  forms  a  blue  solution  at  the  bottom  of  the  test-tube. 

The  principle  of  Lieben's  reaction  is  utilized  in  the  Messinger- 
Huppert  method  of  quantitative  determination  of  acetone,  the  amount 
being  calculated  from  the  quantity  of  iodin  used  in  the  formation  of 
iodoform. 

Leucin  and  Tyrosin — (pp.  364,  424)  are  not  normally  present 
in  the  urine.  They  are  said  to  have  been  met  with  in  the  urine  in 
severe  cases  of  typhus  and  of  variola.  In  yellow  atrophy  of  the  liver 
they  are  constantly  present,  frequently  in  sufficient  quantity  to  be 
found  in  the  crystalline  form 
in  the  sediment,  and  they  have 
also  been  found  in  like  amount 
in  many  cases  of  acute  phos- 
phorus poisoning.  To  test  for 
their  presence  the  urine  of  24 
hours  is  precipitated  with  basic 
lead  acetate  and  filtered  ;  the 
filtrate  is  freed  from  lead  by  pre- 
cipitation with  hydrogen  sulfid 
and  filtration;  the  filtrate  is 
concentrated  to  a  syrup,  washed 
with  a  little  absolute  alcohol, 
and  extracted  with  boiling  dilute  alcohol  containing  ammonia;  the 
ammoniacal  alcoholic  liquid  is  filtered  off  hot,  evaporated  to  small 
bulk,  and  left  to  crystallize.  Tyrosin  crystallizes  in  bundles  of  fine 
colorless  needles  (b  fig.  41),  and  leucin  in  rounded  masses  of  varying 
size,  consisting  of  closely  arranged,  radiating  crystals,  which,  as 
they  occur  in  urinary  sediments,  are  yellow  or  brown  in  color 
(a  fig.  41). 

The  residue  may  be  tested  for  leucin  by  Scherer's  and  Hof- 
meister's  reactions  (p.  365),  and  for  tyrosin  by  Piria's,  Scherer's, 
and  Hofmann's  reactions  (p.  425). 

Cystin — Dithio-diamido-dilactic  acid — (p.  367)  exists  in  the  urine 
normally  in  very  small  amount,  and  in  increased  quantity  in  the 


FIG.  41. 


618  MANUAL    OF    CHEMISTRY 

obscure  pathological  condition  of  cystinuria,  in  which  the  urine  also 
contains  diamins,  such  as  putrescin  and  cadaverin  (p.  333),  and  de- 
posits a  yellowish  sediment  containing  cystin  crys- 
tals (Fig.  42),  or  these  may  be  deposited  to  form 
concretions. 

Cystin  is  best  separated  from  the  urine  and  deter- 
mined by  precipitation  with  benzoyl  chlorid  by  Bau- 
£^  x          ill      mann  and  Goldmann's  method,  or,  less  exactly,  by 
M}J    /^S  precipitation  by  strong   acidulation  with  acetic  acid 

and  purification  of  the  precipitate  by  reprecipitation 
FIG.  42.  from  a  solution  in  ammonia. 


URINARY   CALCULI. 

Urinary  calculi,  or  concretions,  may  be  formed  in  any  part  of  the 
urinary  tract,  but  are  most  frequently  formed  in  the  pelvis  of  the 
kidney  or  in  the  bladder.  They  are  usually  single,  but  may  be  mul- 
tiple, as  many  as  300  having  been  found  in  the  bladder  at  one  time. 
When  multiple,  their  surfaces  are  usually  polished  and  formed  into 
facets  by  mutual  attrition.  They  vary  in  size  from  mere  gravel  to 
masses  as  large  as  a  hen's  egg,  and  weighing  as  much  as  1,500  gms. 
Calculi,  other  than  phosphatic  and  ammonium  urate  concretions,  are 
usually  composed  of  the  same  material  throughout,  constituting 
"primary  deposits."  Phosphatic,  ammonium  urate,  and,  very  rarely, 
calcium  carbonate  calculi  are  produced  as  "secondary  deposits,"  being 
formed  in  an  alkaline  or  subacid  urine,  as  a  so-called  "crust,"  which 
frequently  constitutes  almost  the  entire  mass  of  the  stone,  by  deposi- 
tion upon  a  "nucleus,"  or  nuclei,  consisting  either  of  a  primary 
deposit  or  of  some  foreign  substance.  The  constituents  of  urinary 
calculi  most  frequently  met  with  are  uric  acid,  sodium  urate,  ammo- 
nium urate,  calcium  oxalate,  calcium  phosphate  and  ammonio-mag- 
nesian  phosphate;  those  of  rarer  occurrence  are  cystin,  xanthin, 
urates  of  potassium,  calcium  and  magnesium,  and  calcium  carbonate. 
Of  very  exceptional  occurrence  are  calculi  of  indigo,  silica,  fatty 
acids  (urostealiths),  and  bilirubin  (haematoidin). 

Uric  acid  calculi  are  usually  small  in  size,  and  of  renal  origin, 
although  they  are  met  with  as  vesical  calculi  of  great  size.  They 
are  always  produced  in  a  strongly  acid,  concentrated  urine.  They 
are  gray,  brownish -yellow  or  reddish -brown  in  color,  sometimes 
smooth-surfaced,  but  usually  finely  nodulated,  and  quite  hard.  They 
are  almost  always  primary,  although  occasionally  uric  acid  forms 
alternate  layers  with  calcium  oxalate  in  a  composite  stone. 

Ammonium  urate  is  sometimes  met  with  as  a  primary  deposit 
in  renal  calculi  in  young  children,  which  are  smooth,  yellow,  oval 


URINARY    CALCULI  619 


in  section  and  relatively  soft  and  friable.  Much  more  frequently 
ammonium  urate  constitutes  a  secondary  deposit. 

Oxalate  calculi  are  occasionally  small  and  smooth,  more  usually 
very  rough  and  coarsely  nodulated,  very  hard,  and  varying  in  color 
from  very  pale  yellow  to  dark -brown.  They  are  known  as  "mulberry 
calculi"  from  their  shape. 

Phosphatic  calculi  are  almost  invariably  secondary  deposits,  and 
consist  usually  of  a  mixture  of  calcium  phosphate,  ammonio- magne- 
sium phosphate  and  ammonium  urate.  They  may  attain  great  size, 
are  always  rough -surfaced,  white  to  yellowish  or  pink  in  color,  and 
relatively  soft  and  friable.  Calculi  whose  predominating  constituent 
is  ammonio -magnesian  phosphate  are  called  "lusible  calculi." 

Cystin  calculi,  although  rarely  met  with,  are  of  more  frequent 
occurrence  than  the  other  "rare"  forms.  They  are  primary,  yellow, 
smooth  or  rough,  of  crystalline  structure  throughout,  consisting 
entirely  of  cystin,  quite  soft,  and  usually  small,  although  they  have 
been  known  to  attain  the  size  of  an  egg.  Xanthin  calculi  are  of 
very  rare  occurrence.  They  are  primary,  and  consist  either  entirely 
of  xanthin,  or  of  xauthin  and  uric  acid.  They  vary  in  color  from 
pale  yellow  to  brown,  and  are  sometimes  as  large  as  a  pigeon's  egg. 
Urates  of  potassium,  calcium  and  magnesium  are  occasionally  met 
with  in  urate  calculi,  never  as  the  sole  constituents.  Calcium  car- 
bonate, while  frequently  met  with  as  a  secondary  deposit  in  calculi 
of  large  size  in  the  lower  animals,  is  very  rarely  found  in  the  human 
subject,  in  the  crust  of  a  calculus  formed  with  a  foreign  body  as  a 
nucleus  or  in  a  siliceous  calculus.  Urostealiths  consist  either  entirely 
of  fatty  acids  with  a  little  phosphate,  or  are  covered  with  a  crust 
of  phosphates,  produced  as  a  secondary  deposit.  In  the  former  case 
they  are  of  the  consistency  of  India-rubber  when  moist,  but  become 
hard  and  brittle  when  dry.  Only  five  such  calculi  have  been  de- 
scribed. Indigo  was  found  to  be  one  constituent  of  a  calculus 
weighing  40gms.  formed  in  the  pelvis  of  a  kidney.  Blue  crystals 
of  indigo  have  also  been  met  with  inclosed  in  oxalate  calculi.  Silica 
calculi  are  extremely  rare.  The  author  has  seen  the  nucleus  of  a 
phosphatic  calculus  consisting  entirely  of  silica  and  an  oxid  of 
iron.  An  oxalate  calculus  has  been  found  to  contain  crystals  of 
haematoidin. 

For  the  chemical  examination  of  calculi  the  stone  should  be  sawed 
in  two,  the  sawdust  affording  sufficient  material  for  chemical  exam- 
ination. The  sawdust  from  the  central  portions  of  the  calculus 
should  be  collected  and  examined  separately  from  that  derived  from 
the  crust.  The  following  scheme  of  analysis  will  be  found  useful  for 
the  examination  of  calculus  dust,  a  separate  portion  of  the  material 
being  used  for  each  operation,  except  where  otherwise  directed  : 


620  MANUAL    OF    CHEMISTRY 

SCHEME    FOR    DETERMINING    THE    COMPOSITION    OF    URINARY 

CALCULI. 

1.  Heat  a  portion  on  platinum  foil  : 

a.  It  is  entirely  volatile 2 

b.  A  residue  remains 5 

2.  Moisten  a  portion  with  HNO3;   evaporate  to  dryness  at  low  heat; 

add  NH4HO  : 

a.  A  red  color  is  produced 3 

6.* No  red  color  is  produced 4 

3.  Treat  a  portion  with  KHO,  without  heating  : 

a.  An  ammoniacal  odor  is  observed Ammonium  urate. 

b.  No  ammoniacal  odor Uric  acid. 

4.  a.  The  HNOs  solution  becomes  yellow  when  evaporated;   the  yel- 

low residue  becomes  reddish -yellow  on  addition  of  KHO, 

and,  on  heating  with  KHO,  violet- red Xanthin. 

b.  The  HNOa  solution  becomes  dark  brown  on  evaporation, 

Cyst  in. 

5.  Moisten  a  portion  with  HNOs;   evaporate  to  dryness  at  low  heat; 

add  NH4HO  : 

a.  A  red  color  is  produced 6 

b.  No  red  color  is  produced 9 

6.  Heat  before  the  blow -pipe  on  platinum  foil  : 

a.  Fuses 7 

b.  Does  not  fuse     ...      8 

7.  Bring  into  blue  flame  on  platinum  wire  : 

a.  Colors  flame  yellow Sodium  urate. 

b.  Colors  flame  violet Potassium  urate. 

8.  The  residue  from  6  : 

a.  Dissolves  in  dil.  HC1  with  effervescence;   the  solution  forms  a 

white  ppt.  with  ammonium  oxalate     Calcium  urate. 

b.  Dissolves  with  slight  effervescence  in  dil.  H2S04;  the  solution, 

neutralized  with  NH4HO,  gives  a  white  ppt.  with  HNa2PO4, 

Magnesium  nrafc. 

9.  Heat  before  the  blow -pipe  on  platinum  foil  : 

a.  It  fuses Ammonia -magnesian  phosphate. 

b.  It  does  not  fuse 10 

10.  The  residue  from  9,  when  moistened  with  H2O,  is  : 

a.  Alkaline 11 

b.  Not  alkaline Tricalcic  phosphate. 


MILK  621 

11.  The  original  substance  dissolves  in  HC1  : 

a.  With  effervescence      Calcium  carbonate. 

b.  Without  effervescence Calcium  oxalate. 


MILK 

As  the  milk  of  the  cow  has  been  the  best  studied,  and  as  it  is  an 
important  article  of  food,  it  will  be  first  considered,  and  the  difference 
between  it  and  human  milk  will  be  subsequently  referred  to. 

Physical  Properties/ — Milk  is  white,  yellowish,  or,  in  thin  layers, 
or  if  diluted  with  water,  bluish.  It  is  opaque,  the  opacity  being 
due  to  the  fact  that  it  is  an  emulsion,  and  that  light  is  extinguished 
by  the  repeated  refractions  in  passing  between  the  watery  liquid  and 
the  oil  globules.  Consequently,  the  richer  the  milk  is  in  fat,  the 
thinner  the  layer  in  which  it  is  capable  of  causing  a  certain  degree 
of  extinction  of  light;  a  fact  which  is  utilized  in  some  forms  of 
"milk -testers."  The  odor  of  milk  is  faint,  but  characteristic,  and 
its  taste  is  sweetish. 

Its  reaction  when  fresh  is  amphoteric,  the  mean  alkalinity  being 
equivalent  to  41  cc.  N/10  NaHO  for  100  cc.  milk  (phenolphthalein), 
and  its  mean  acidity  equivalent  to  19.5  cc.  N/10  H^SO*.  In  air  the 
reaction  soon  turns  to  acid,  by  reason  of  formation  of  lactic  and  suc- 
cinic  acids  from  the  milk-sugar  by  micro-organisms,  a  change  which 
takes  place  during  the  "souring"  of  milk,  and  has  an  influence  upon 
the  action  of  heat  upon  it.  Fresh  milk  does  not  coagulate  upon 
boiling,  even  after  treatment  with  carbon  dioxid.  As  it  gradually 
sours,  it  first  coagulates  on  boiling  after  treatment  with  CO2;  then 
on  boiling  alone;  at  a  later  stage  it  coagulates  by  the  action  of  C(>2 
at  the  ordinary  temperature;  and,  finally,  it  coagulates  spontaneously, 
without  C(>2  or  heat,  expressing  a  yellowish  liquid,  the  whey.  This 
change  is  due  to  bacterial  action,  and  may  be  prevented  by  sterilizing 
the  milk  by  heat,  or  by  antiseptics. 

The  specific  gravity  of  cow's  milk  varies  from  1027  to  1035,  being 
higher  with  skimmed  milk,  and  Idwer  with  very  rich  milk  and  with 
watered  milk.  The  lactometer  is  simply  a  specially  graduated 
spindle  by  which  the  sp.  gr.  of  the  milk  is  determined,  and  milk 
having  a  sp.  gr.  below  1027  is  considered  as  adulterated.  It  must  be 
remembered,  however,  that  as  the  specific  gravity  is  raised  by  skim- 
ming and  lowered  by  watering,  the  original  sp.  gr.  may  be  main- 
tained by  practicing  both  forms  of  adulteration  to  suitable  degrees; 
and  also  that  very  rich  milk  has  a  lower  sp.  gr.  than  that  less  rich 
in  cream.  Therefore,  the  lactometer  can  only  be  relied  upon  when 
used  in  connection  with  the  creamometer,  or  other  means  of  deter- 


622  MANUAL    OF    CHEMISTRY 

mining  the  proportion  of  fat.  The  average  sp.  gr.  of  good  cow's  milk 
is  1030,  and  the  percentage  of  cream  13. 

Composition. —  Milk  consists  of  a  watery  solution  of  proteins, 
lactose  and  mineral  salts,  sometimes  called  the  plasma,  which  holds 
in  suspension  minute  globules  of  fat,  sometimes  called  the  corpus- 
cles. On  standing,  the  fat  rises,  more  or  less  completely,  to  the 
surface,  forming  a  layer  much  richer  in  fat  than  the  milk,  which  is 
the  cream,  upon  removal  of  which  the  skim-milk  remains.  The 
separation  of  fat  is  more  rapidly  and  completely  effected  by  cream- 
separators,  which  are  centrifugal  machines  adapted  to  this  purpose. 
The  "corpuscles,"  which  contain  all  the  fat  of  the  milk,  number 
from  1  to  5%  million  per  cc.,  and  are  from  .0024  to  .0046  mm.  in 
diameter.  It  is  probable  that  the  fat -globules  of  milk  are  enclosed 
in  an  envelope,  because,  unless  the  milk  have  been  previously  treated 
with  alkali,  agitation  with  ether  does  not  readily  extract  the  fat,  and 
also  because  the  globules  are  stained  by  certain  agents  which  do  not 
stain  fats.  Besides  fat,  the  globules  contain  small  quantities  of 
lecithins,  cholesterol,  and  a  yellow  coloring -matter.  The  fat  of  milk, 
butter-fat,  is  more  complex  in  composition  than  other  fats  and  oils, 
from  which  it  differs  particularly  in  containing  a  larger  propor- 
tion of  the  glycerids  of  the  lower,  volatile,  fatty  acids,  a  fact 
which  is  taken  advantage  of  for  the  detection  of  adulterations 
of  butter.  Milk-fat,  when  saponified,  yields  about  94%  of  fatty 
acids,  of  which  86  to  89%  consists  of  insoluble,  non- volatile 
acids,  palmitic,  stearic  and  oleic,  with  minute  quantities  of  caprylic, 
capric,  lauric  and  arachic  acids  (p.  283),  the  oleic  acid  constituting 
from  rV  to  TO  of  the  whole.  The  remaining  5  to  8%  consist  of 
soluble,  volatile  acids,  butyric  (f  to  T)  and  caproic  (f  to  f).  Other 
fats  and  oils  yield  only  mere  traces  of  volatile,  soluble  acids  on 
saponification.  Whether  these  acids  exist  in  milk  and  butter  as 
separate  glycerids,  such  as  tributyrin,  C3H5( C^Oah,  tripalrnitin, 
CaHsCCieHa^h,  and  tristearin,  C3Hs(Ci8H35O2),  or  as  mixed  gly- 
cerids, such  as  C3H5(C4H7O2)(Ci6H3iO2)(Ci8H35O2),  is  unknown. 

Butter. —  Good,  natural  butter  contains  80  to  90%  of  butter -fat, 
6  to  10%  of  water,  2  to  5%  of  card  (casein),  2  to  5%  of  salt,  and, 
almost  always,  some  artificial  "butter -color."  About  the*  only  adul- 
teration of  butter  now  practiced  is  by  admixture  of  other  animal 
fats  (beef  or  mutton  tallow),  and  vegetable  or  animal  oils  (cotton- 
seed or  lard -oil),  or  by  substitution  of  imitation  butter.  Oleomar- 
garine is  a  product  made  in  imitation  of  butter,  which  it  resembles 
very  closely  in  color,  taste,  odor,  and  general  appearance.  It  is 
made  from  beef-fat,  which  is  hashed,  steamed,  and  subjected  to 
pressure  at  a  carefully  regulated  temperature.  Under  this  treatment 
it  is  separated  into  two  fatty  products,  one  a  white  solid,  "stearin," 


[ILK  623 

the  other  a  faintly  yellow  oil,  "oleo-oil."  This  oil  is  then  mixed 
with  milk,  and  the  remaining  steps  in  the  manufacture  are  the  same 
as  in  making  butter  from  cream.  "Butterine,"  "suine,"  etc.,  are 
products  made,  by  modifications  of  the  above  process,  from  beef  or 
mutton -tallow,  lard  and  cotton -seed  oil. 

Milk-plasma  —  the  liquid  portion  of  the  milk  remaining  after 
complete  removal  of  the  fat -globules,  contains  the  dissolved  con- 
stituents. These  consist  of  at  least  three  proteins:  Caseinogen,  the 
parent  substance  from  which  the  casein  is  derived,  lactalbumin,  and 
lactoglobulin;  two  carbohydrates,  milk  sugar  and  dextrine-like  sub- 
stance; mineral  salts;  and  small  quantities  of  lecithins,  nuclein, 
cholesterol,  urea,  creatin,  creatinin,  and  calcium  citrate. 

Casein  —  is  the  protein  produced  from  the  caseinogen  of  milk 
by  the  coagulating  action  of  the  rennet  from  the  stomach  of  the 
calf.  Probably  the  caseinogens,  and  the  caseins  derived  therefrom, 
in  the  milk  of  different  kinds  of  animals  are  not  identical  with 
each  other.  That  from  human  milk  and  that  from  the  milk  of  the 
cow  differ  in  the  form  of  the  coagulum,  in  solubility  in  acids,  and 
in  the  nature  of  the  products  of  decomposition.  The  casein  of  cow's 
milk  is  a  nucleoalbumen,  and,  on  digestion  with  pepsin  and  hydro- 
chloric acid,  leaves  a  pseudonuclein,  which  is  not  the  case  with  the 
casein  from  human  milk.  It  contains  0.8%  of  sulfur,  and  0.85%  of 
phosphorus.  Casein,  which  is  the  principal  protein  of  cheese,  is, 
when  dry,  a  white  powder,  very  sparingly  soluble  in  water  and  in 
solutions  of  neutral  salts,  except  that  it  is  somewhat  soluble  in  1% 
solutions  of  sodium  fluorid  or  of  potassium  or  ammonium  oxalate. 
It  behaves  as  an  acid  towards  alkaline  solutions,  in  which  it  dis- 
solves, forming  solutions  which  may  be  neutral  or  even  acid,  if  the 
proportion  of  alkali  be  small.  It  expels  carbon  dioxid  from  calcium 
carbonate,  and  forms  a  soluble  compound  with  calcium  phosphate. 
Its  solutions  do  not  coagulate  by  heat.  Addition  of  a  very  small 
quantity  of  dilute  hydrochloric  or  acetic  acid  causes  precipitation  of 
casein  from  its  solutions,  less  readily  in  the  presence  of  neutral  salts; 
the  precipitate  dissolving  readily  in  an  excess  of  the  acid,  and  being 
again  produced  by  marked  excess  of  mineral  acids.  Neutral  solu- 
tions are  precipitated  by  salting  with  sodium  chlorid  or  magnesium 
sulfate,  and  by  solutions  of  alum,  or  of  zinc  or  copper  salts.  The 
most  notable  property  of  caseinogen  is  its  coagulation  (conversion 
into  casein  or  paracasein)  by  the  action  of  rennet  (chymosin),  in 
the  presence  of  calcium  salts.  Chymosin  alone  causes  a  change  in 
caseinogen,  but  not  coagulation;  for  if  a  solution  of  caseinogen 
be  treated  with  chymosin  no  coagulation  occurs,  but  if  the  chymosin 
be  then  destroyed  by  heat,  a  coagulum  is  formed  by  addition  of  a 
calcium  salt. 


624 


MANUAL    OF    CHEMISTRY 


On  digestion  with  pepsin -hydrochloric  acid,  cow's  casein  dis- 
solves, leaving  a  residue  of  a  nucleoalburaen,  whose  quantity  and 
whose  phosphorus -content  vary.  Indeed,  with  a  large  excess  of 
pepsin -hydrochloric  acid,  no  residue  remains.  By  tryptic  digestion 
the  phosphorus  is  split  off,  in  part  as  phosphoric  acid,  and  in  part 
in  organic  combination. 

Casein  may  be  obtained  from  milk  by  dilution  with  four  volumes 
of  water,  precipitation  by  addition  of  acetic  acid  to  1  p/m,  repeated 
resolution  in  dilute  alkali  and  reprecipitation  by  acetic  acid,  washing 
with  water,  drying,  and  washing  with  alcohol,  and  finally  with  ether. 

Lactalbumin  —  is  a  protein  containing  no  phosphorus,  and  1.73% 
of  sulfur.  It  has  the  properties  of  the  albumins,  and  resembles 
serum  albumin,  having  about  the  same  coagulation -temperature,  72° 
to  84°,  varying  with  the  proportion  of  salts  present,  but  having  a 
lower  specific  rotary  power:  [a]D  =  — 37°.  It  may  be  separated 
from  milk,  after  removal  of  lactoglobulin  and  casein  by  salting  with 
magnesium  sulfate,  by  precipitation  with  acetic  acid. 

Lactoglobulin  —  closely  resembling,  if  not  identical  with  serum 
globulin,  is  a  protein  precipitable  from  milk,  after  removal  of  casein 
by  salting  with  sodium  chlorid,  by  saturation  with  magnesium 
sulfate. 

Lactose — see  p.  272. 

Mineral  salts  —  exist  in  cow's  milk  in  the  proportion  of  about 
0.7%.  They  consist  of  the  chlorids  and  phosphates  of  sodium, 
potassium,  calcium  and  magnesium,  and  traces  of  iron. 

Human  milk  —  differs  from  cow's  milk  principally  in  the  pro- 
portion of  the  several  constituents,  and  in  the  nature  of  the  proteins. 
The  composition  of  cow's  milk  and  of  human  milk  is  given  by 
Konig  as  follows: 


Cow's  MILK 

I 

lUMAN   MlLl 

i 

Mean 

Minimum 

Maximum 

Mean 

Minimum 

Maximum 

Water                .... 

87  41 

80  32 

91  50 

87  21 

83  69 

90  90 

Total  solids  
Fat  

11.59 
3.66 

8.50 
1.15 

19.68 
7.09 

12.71 

3.78 

9.10 
1.71 

16.31 
7.60 

Milk-sugar       .... 

4  92 

3  20 

5  67 

6  04 

4  11 

7  80 

Casoin           

3  01 

1  17 

7  40 

1.03 

0  18 

1  90 

Albumin        

0.75 

0.21 

5.04 

1.26 

0.39 

2  35 

Protsins        

3.76 

1.38 

12.44 

2.29 

0.57 

4  25 

Ash     

0.70 

0.50 

0.78 

0.31 

0.14 

f 

Therefore,  in  human  milk  the  proportion  of  proteins  is  less,  and 
that  of  sugar  greater  than  in  cow's  milk. 

The  casein  of  human  milk  is,  apparently,  not  a  nueleoalbumen, 


at  all  events  it  leaves  no  residue  of  pseudonuclein  on  digestion  with 
pepsin -hydrochloric  acid.  It  does,  however,  contain  phosphorus  in 
somewhat  less  proportion  than  cow's  casein,  0.68%.  It  is  coagulated 
incompletely  by  rennet  in  fine,  separate  flocculi,  while  cow's  casein  is 
coagulated  by  rennet  in  dense,  curdy  masses.  Human  casein  is  more 
difficultly  precipitated  by  acids  than  cow's  casein,  and  is  more 
readily  soluble  in  slight  excess  of  the  acid.  These  differences  are  not 
due  to  differences  in  the  nature  or  amount  of  the  salts  present,  but 
to  differences  in  the  proteins  themselves,  which  also  differ  in  their 
chemical  composition,  human  casein  containing  less  carbon,  nitrogen 
and  phosphorus  than  cow's  casein,  and  more  hydrogen,  oxygen  and 
sulfur.  The  spontaneous  coagulation  of  human  milk  on  exposure  to 
air  at  the  ordinary  temperature  takes  place  more  slowly  than  that 
of  cow's  milk.  The  quantity  of  proteins  in  human  milk  is  notably 
greater  early  in  lactation  than  later,  being  as  high  as  3  p/m  in  the 
earlier  stages.  The  proportion  of  milk-sugar,  on  the  contrary, 
increases  with  the  duration  of  lactation. 

Besides  caseinogen,  lactalbumin  and  lactoglobulin,  human  milk 
contains  another  protein,  opalisin,  which  contains  a  large  propor- 
tion of  sulfur,  4.7%. 

Abnormal  Milk. — It  will  be  seen  by  the  table  on  page  624  that 
the  proportion  of  fat,  sugar  and  proteins  in  both  cow's  milk  and 
human  milk  vary  within  quite  wide  limits.  A  milk  containing  less 
than  the  minimum  of  these  constituents  there  given  is  certainly 
abnormal,  and  one  containing  no  more  than  the  mean  is  of  inferior 
quality.  The  New  York  state  dairy  law  declares  any  milk  found  on 
analysis  to  contain  "less  than  12%  of  milk  solids,  which  shall  con- 
tain not  less  than  3%  of  fat "  to  be  adulterated.  These  limits  are 
fixed  upon  the  assumption,  based  upon  a  great  number  of  analyses, 
that  a  milk  falling  below  the  requirements,  if  not  fraudulently 
adulterated,  is  the  product  of  cows  kept  under  improper  hygienic 
conditions,  or  diseased.  The  quality  of  milk,  whether  of  women  or 
of  cows,  is  affected  by  the  physical  condition  of  the  individual,  the 
nutrition,  and  the  composition  of  the  food,  the  duration  of  lactation, 
and  the  mental  emotions.  The  last-named  influence  the  quality  of 
the  milk  much  more  seriously  than  is  generally  appreciated.  The 
milk  of  cows  which  are  harassed  or  excited  has  been  found  to  be 
much  more  liable  to  cause  alimentary  disturbances  in  infants  than 
that  obtained  from  animals  which  are  gently  treated  and  kept  free 
from  excitement.  It  is  also  well  known  that  the  milk  of  women 
during  violent  mental  excitement  may  become  absolutely  poisonous 
to  the  nursing  infant. 

Cow's  milk  has  been  frequently  the  medium  of  transmission  of 
disease.  Bacteria  are  found  in  the  freshly  -  drawn  milk  of  cows 

40 


626  MANUAL    OF    CHEMISTRY 

affected  by  disease,  and  it  has  been  stated  that  tuberculosis  may 
thus  be  transmitted  from  the  cow  to  the  human  subject.  Less  open 
to  question  is  the  transmission  of  diphtheria,  scarlet  fever,  and, 
particularly,  typhoid,  by  contamination  of  the  milk  by  exposure  to 
the  air,  or  by  admixture  of  contaminated  water,  particularly  as  milk 
is  an  excellent  nutrient  material  for  bacteria.  The  physical  qualities 
of  milk  are  also  sometimes  modified  by  bacterial  action,  the  milk 
becoming  bitter  in  taste,  or  ropy  in  consistency,  or  red  or  blue  in 
color. 

Medicinal  and  poisonous  substances  taken  by  the  mother  may 
pass  into  the  milk  in  quantity  sufficient  to  cause  serious  effects  upon 
the  nursing  infant.  Thus  infants  are  frequently  narcotized  by  opiates 
taken  by  the  mother,  and  at  least  two  instances  of  fatal  poisoning 
by  this  means  have  been  reported. 

The  adulteration  of  milk  now  is  practically  limited  to  the  addition 
of  water,  or  the  removal  of  cream,  or  both. 

Analysis  of  Milk. —  The  constituents  of  milk  usually  determined 
in  milk  analysis  are:  total  solids  (milk -solids),  fat,  solids  not  fat, 
and  ash.  A  simple  method,  and  one  giving  sufficiently  accurate 
results,  is  that  of  Sharpies:  ten  cc.  of  the  milk  are  measured  out 
into  a  weighed,  flat  platinum  dish  (milk-dish),  and  weighed.  The 
difference  between  this  weight  and  that  of  the  dish  is  the  weight 
of  milk  used.  The  dish  is  then  placed  on  the  water -bath  until  the 
milk  is  evaporated  to  dryness,  heated  for  half  an  hour  in  an  air- 
oven  at  105°,  cooled  and  weighed.  This  weight,  minus  the  weight 
of  the  dish,  is  the  weight  of  milk-solids  in  the  weight  of  milk  used. 
The  dish  is  then  filled  with  petroleum -ether  (obtained  by  distilling 
gasolene  on  the  water-bath),  which  is  poured  off  from  the  solid 
residue,  which  usually  adheres  firmly  to  the  dish;  and  the  treatment 
with  petroleum -ether  repeated  six  times.  The  residue  is  heated 
for  a  few  minutes  in  the  air -oven,  cooled,  and  weighed.  This 
weight,  minus  that  of  the  empty  dish,  is  that  of  the  solids  not  fat; 
and,  subtracted  from  the  weight  of  milk -solids,  gives  the  weight 
of  fat  in  the  amount  of  milk  used.  The  residue  is  then  burnt  to 
a  white  ash,  cooled  and  weighed,  giving  the  amount  of  ash. 

The  extraction  of  fat  by  the  above  method  is  not  complete,  and 
therefore  the  determination  of  fat  is  affected  with  a  slight  minus 
error.  When  more  accurate  determination  of  fat  is  desired,  Adams' 
method  is  to  be  preferred:  strips  of  thin  blotting-paper  about  50 
cent,  long  and  6  cent,  wide,  which  have  been  freed  from  fat  by 
extraction  with  ether  and  with  alcohol,  dried  and  weighed,  along 
with  the  platinum  wire  below  referred  to,  are  used.  The  milk  sam- 
ple is  placed  in  a  small  wash -bottle,  which  is  then  weighed.  One 
of  the  paper  strips  is  suspended  in  a  horizontal  position,  and  from 


MILK  627 

8  to  10 cc.  of  the  milk  are  distributed  over  it  from  the  wash-bottle, 
which  is  then  re  weighed  to  determine  the  amount  of  the  sample 
used.  When  the  milk  upon  the  paper  strip  has  become  air -dried, 
the  strip  is  coiled  into  a  spiral,  about  which  the  platinum  wire  is 
fastened,  and  which  is  then  dried  in  an  air- oven  at  105°.  When 
dry,  the  spiral  is  cooled  and  weighed,  to  determine  the  total  solids, 
and  then  extracted  with  ether  in  a  Soxhlet  extractor.  The  fat  is 
determined  by  evaporation  of  the  ether  extract,  and  weighing  the 
residue. 

Of  the  more  rapid,  physical  methods  of  fat -determination  prob- 
ably the  most  satisfactory  is  that  of  Babcock:  The  milk  is  mixed 
with  an  equal  volume  of  sulfuric  acid,  transferred  to  a  small  bottle 
having  a  long,  thin,  graduated  neck,  constructed  for  the  purpose, 
and  rotated  in  a  centrifugal.  The  percentage  of  fat  is  read  off  on 
the  graduation. 

For  the  determination  of  total  proteins  and  sugar  in  the  same  sam- 
ple, Ritthausen's  method  is  generally  used:  25  gm.  of  the  milk  are 
diluted  with  water  to  400  cc.,  10  cc.  of  a  solution  of  CuS04  contain- 
ing 6.5  gm.  to  the  litre,  and  a  solution  of  KHO  (14.2  gm.  to  the 
litre),  or  of  NaHO  (10.2  gm.  to  the  litre)  are  added  so  that  the 
reaction  remains  faintly  acid  or  neutral  (it  must  not  become  alkaline) . 
When  the  precipitate  of  proteins  has  formed,  100  cc.  of  water  are 
added,  the  mixture  is  stirred  and  filtered  through  a  small  filter  of 
known  nitrogen -content.  The  filtrate  is  used  for  the  sugar  deter- 
mination: 100  cc.  are  added  to  50  cc.  of  boiling  Fehling's  solution, 
and  the  determination  is  concluded  as  usual.  The  protein  coagulum 
is  washed,  by  decantation  and  upon  the  filter,  with  water,  and  the 
proportion  of  nitrogen  is  determined  in  the  filter  and  precipitate  by 
Kjeldahl's  method.  The  nitrogen  found,  multiplied  by  6.37,  gives 
the  protein -content. 


APPENDIX. 


. 


APPENDIX  A. 

ORTHOGRAPHY  AND  PRONUNCIATION  OF  CHEMICAL  TERMS. 

In  1887  a  committee  was  appointed  by  the  American  Association 
for  the  Advancement  of  Science,  to  consider  the  question  of  securing 
uniformity  in  the  spelling  and  pronunciation  of  chemical  terms.  The 
work  of  this  committee  extended  through  the  four  following  years. 
As  a  result  of  widespread  correspondence  and  detailed  discussion  at 
the  annual  meetings  of  the  Chemical  Section  of  the  American  Asso- 
ciation, the  following  rules  have  been  formulated  and  adopted  by 
e  Association. 

A  circular  embodying  the  substance  of  these  rules  has  been  issued 
by  the  Bureau  of  Education  at  Washington,  and  distributed  among 
chemists  and  teachers  of  chemistry,  with  a  recommendation  of  their 
general  adoption. 

GENERAL    PRINCIPLES    OF    PRONUNCIATION. 

1.  The  pronunciation  is  as  much  in  accord  with  the  analogy  of 
the  English  language  as  possible. 

2.  Derivatives  retain  as  far  as  possible  the  accent  and  pronun- 
ciation of  the  root  word. 

3.  Distinctly  chemical   compound  words  retain  the   accent   and 
pronunciation  of  each  portion. 

4.  Similarly   sounding    endings    for   dissimilar    compounds    are 
avoided,  hence  -in,  -id,  -ite,  -ate. 

ACCENT. 

In  polysyllabic  chemical  words  the  accent  is  generally  on  the 
antepenult;  in  words  where  the  vowel  of  the  penult  is  followed  by 
two  consonants,  and  in  all  words  ending  in  -ic,  the  accent  is  on  the 
penult. 

PREFIXES. 

All  prefixes  in  strictly  chemical  words  are  regarded  as  parts  of 
compound  words,  and  retain  their  own  pronunciation  unchanged  (as 
a'ceto-,  a'mido-,  a'zo-,  hy'dro-,  i'so-,  ni'tro-,  mtro'so-). 

(631) 


632 


MANUAL    OF    CHEMISTRY 


ELEMENTS. 


In  words  ending  in  -ium,  the  vowel  of  the  antepenult  is  short  if  i 
(as  Iri'dium),  or  y  (as  dldy'mium),  or  if  before  two  consonants  (us 
ca'lcium),  but  long  otherwise  (as  tita'nium,  sSle'nium,  chrd'imum). 


alii'minium 

e'rbium 

me'rcury 

'so'dium 

a'ntimony 

flu'orln 

moly'bdenum 

str5'ntium 

a'rsSnic 

ga'llium 

nl'ckel 

(shium) 

ba'rium 

germa'nium 

m'trogen 

sii'lfur 

bi'smuth  (biz) 

glu'cinum 

6'smium 

13,'ntalum 

bo'ron 

gold 

6'xygen 

tellu'rium 

bro'mln 

hy'drogen 

palla'dium 

te'rbium 

ca'dmium 

I'ndium 

phSs'phorus 

thallium 

ca'lcium 

I'odln 

pl&'tinum 

tho'rium 

ca'rbon 

irI'dium 

potS'ssium 

tin 

ce'rium 

iron 

rho'dium 

tlta'nium 

ce'sium 

IS/nthanum 

rub  I'd  ium 

tu'ngsten 

chlo'rln 

lead 

ruthe'nium 

ura'nium 

chro'mium 

H'thium 

sama'rium 

vSna'dium 

co'balt 

magne'sium 

scS/ndium 

ytte'rbium 

colu'mbium 

(zhium) 

sSle'nium 

y'ttrium 

co'pper 

ma'nganese 

gflicon 

zinc 

dldy'mium 

(eze) 

silver 

zirco'nium 

Also:  ^mmo'nium,  phospho'nium,  hS/logen,  cyaxnogen,  amix- 
dogen. 

Note  in  the  above  list  the  spelling  of  the  halogens,  cesium  and 
sulfur;  f  is  used  in  the  place  of  ph  in  all  derivatives  of  sulfur  (as 
sulfuric,  sulfite,  sulfo-,  etc.). 

TERMINATIONS    IN   -ic. 

The  vowel  of  the  penult  in  polysyllables  is  short  (as  cya/nic, 
fuma'rie,  arsenic,  silixcic,  I6/dic,  butyric),  except  (1)  u  when  not 
used  before  two  consonants  (as  mercuric,  pru/ssic),  and  (2)  when 
the  penult  ends  in  a  vowel  (as  benzoxic,  olexic) ;  in  dissyllables  it  is 
long  except  before  two  consonants  (as  bo'ric,  cftric).  Exception: 
ace'tic  or  acSxtic. 

The  termination  -ic,  is  used  for  metals  only  where  necessary  to 
contrast  with  -ous  (thus  avoid  aluminic,  ammonic,  etc.). 


Fate,  fat,  far,  mSte,  m6t,  pine,  pin,  marine,  n5te,  n8t,  move,  tube,  tub,  rule, 
my,  y-I. 

'  Primary  accent;  "  secondary  accent.  N.  B. — The  accent  follows  the  vowel 
of  the  syllable  upon  which  the  stress  falls,  but  does  not  indicate  the  division  of 
the  word  into  syllables. 


OETHOGRAPHY    AND    PRONUNCIATION  633 


TERMINATIONS    IN    OUS. 

The  accent  follows  the  general  rule  (as  plaxtinous,  su'lfurous, 
phosphorous,  coba'ltous).  Exception:  ace'tous. 

TERMINATIONS    IN    -ate    AND    -ite. 

The  accent  follows  the  general  rule  (as  a'cetate,  va'nadate) :  in 
the  following  words  the  accent  is  thrown  back:  a'bietate,  a'lcoholate, 
a'eetonate,  a'ntimonite. 

TERMINATIONS    IN    -id    (FORMERLY    -ide). 

The  final  e  is  dropped  in  every  case  and  the  syllable  pronounced 
id  (as  ehlo'rid,  I'odid,  hy'drid,  ti'xid,  hydro'xid,  su'lfid,  a'imd, 
a'nilid,  mur^'xid). 

TERMINATIONS   IN  -ane,  -ene,  -ine,  AND  -one. 

The  vowel  of  these  syllables  is  invariably  long  (as  methane, 
e'thaiie,  na'phthalene,  anthracene,  pro'pine,  qui'none,  Acetone, 
ke'tone). 

A  few  dissyllables  have  no  distinct  accent  (as  benzene,  xylene, 
cetene). 

The  termination  -ine  is  used  only  in  the  case  of  doubly  unsatu- 
rated  hydrocarbons,  according  to  Hofmann's  grouping  (aspropine). 

TERMINATIONS    IN    -in. 

In  names  of  chemical  elements  and  compounds  of  this  class,  which 
includes  all  those  formerly  ending  in  -ine  (except  doubly  unsaturated 
hydrocarbons),  the  final  e  is  dropped,  and  the  syllable  pronounced 
-in  (as  chK/rin,  bro^m,  etc.,  ^min,  a^iilin,  mo'rphin,  qui'nm 
(kwfnin),  vanillin,  alloxaxntin,  absixnthin,  emii^sin,  caxffeln, 
co'cain). 

TERMINATIONS    IN    -ol. 

This  termination,  in  the  case  of  specific  chemical  compounds,  is 
used  exclusively  for  alcohols  (and  phenols,  W.),  and  when  so  used  is 

Fate,  fat,  far,  mete,  m6t,  pine,  pin,  marine,  note,  nSt,  move,  tube,  tub,  rule, 
my,  y  =  I. 

'  Primary  accent;  "  secondary  accent.  N.  B.— The  accent  follows  the  vowel 
of  the  syllable  upon  which  the  stress  falls,  but  does  not  indicate  the  division  of 
the  word  into  syllables. 


634  MANUAL    OF    CHEMISTRY 

never  followed  by  a  final  e.  The  last  syllable  is  pronounced  -61 
(as  gly'col,  phe'nol,  cre'sol,  thy'mol  (ti),  gly'cerol,  qul'nol.) 
Exceptions:  Slcohtil,  a'rgftl. 


TERMINATIONS    IN    -ole. 

This  termination  is  always  pronounced  -ole,  and  its  use  is  limited 
to  compounds  which  are  not  alcohols  (or  phenols,  W.)  (as  i'ndole). 


TERMINATIONS    IN    -yl. 

No  final  e  is  used;  the  syllable  is  pronounced  yl  (as  a'cetyl,  a'mjtt, 
oe'rotyl,  ce'tyl,  Sibyl). 


TERMINATIONS    IN    -yde. 

The  y  is  long  (as  aldehyde). 

TERMINATIONS   IN  -meter. 

The  accent  follows  the  general  rule  (as  hydrometer,  barft'meter, 
lactometer) .  Exception:  words  of  this  class  used  in  the  metric 
system  are  regarded  as  compound  words,  and  each  portion  retains 
its  own  accent  (as  ce'/ntime"ter,  millime"ter,  kilome"ter). 


MISCELLANEOUS  WORDS  WHICH  DO  NOT  FALL  UNDER  THE 
PRECEDING  RULES. 

Note  the  spelling:  albumen,  albuminous,  albuminiferous,  asbestos, 
gramme,  radical. 

Note  the  pronunciation:  alkaline,  alloy  (n.  and  v.),  allotropy, 
allotropism,  I'somerism,  pOlyrnerism,  apparatus  (sing,  and  plu.), 
aqua  regia,  baryxta,  centigrade,  concentrated,  crystallm  or  crys- 
talline, electrolysis,  liter,  molecule,  mSle^cular,  nomenclature, 
olexfiant,  valence,  u^niva^lent,  bi'va^lent,  trl'va^lent,  quadrivalent, 
titrate. 


Fate,  fat,  far,  mete,  mfit,  pine,  pin,  marine,  note,  nSt,  move,  tube,  tub,  rule, 
my,  y  =  J. 

'  Primary  accent;  "  secondary  accent.  N.  B. — The  accent  follows  the  vowel 
of  the  syllable  upon  which  the  stress  falls,  but  does  not  indicate  the  division  of 
the  word  into  syllables. 


ORTHOGRAPHY  AND  PRONUNCIATION 


635 


A    LIST    OF    WORDS    WHOSE    USE    SHOULD    BE    AVOIDED    IN    FAVOR    OF 
THE    ACCOMPANYING    SYNONYMS. 


For  — 

sodic,    calcic,    zincic,    nickelic,    etc., 
chlorid,  etc. 


Use  — 

sodium,  calcium,  zinc,  nickel,  etc., 
chlorid,  etc.  (vid.  terminations 
in  -ic  supra). 

arsenetted  hydrogen arsin 

antimonetted  hydrogen stibin 

phosphoretted  hydrogen phosphin 

sulfuretted  hydrogen,  etc hydrogen  sulfid,  etc. 


For  — 


Use— 


For— 


Use— 


beryllium glucinoim 

niobium columbium 

glycerin glycerol 

hydroquinone  (and 

hydrochinon)  .    .  quinol 
pyrocatechin  . 
resorcin,  etc.  . 
mannite  .    .    . 
dulcite,  etc.    . 


.  catechol 
.  resorcinol,  etc, 
.  mannitol 
.  dulcitol,  etc. 


benzol benzene 

toluol,  etc toluene,  etc. 

thein caffein 


furfurol furfuraldehyde 

fucusol fucusaldehyde 

anisol methyl  phenate 

phenetol ethyl  phenate 

anethol methyl  allylphenol 


alkylogens  .   . 
titer  (n.)     .   . 

titer  (v.)     .    . 
monovalent    . 
divalent,  etc. 
quantivalence 


.  alkyl  haloids 
.  strength  or  stand- 
ard 

.  titrate 
.  univalent 
.  bivalent,  etc 
.  valence 


APPENDIX  B.— TABLES. 


TABLE    I.— SOLUBILITIES. 
PRESENIUS. 

W  or  w  =  soluble  in  H2O.     A  or  a  =  insoluble  in  H20;   soluble 
in  HC1,  HNOs,  or  aqua  regia.     I  or  i  =  insoluble  in  H2O  and  acids. 
W-A  =  sparingly  soluble  in   H2O,   but   soluble   in   acids.     W-I  = 
sparingly  soluble  in  H20  and  acids.     A-I  =  insoluble  in  H2O,  spar- 
ingly soluble  in  acids.     Capitals  indicate  common  substances. 


Aluminium. 

Ammonium. 

Antimony. 

W 

Bismuth. 

Cadmium. 

Calcium. 

Chromium. 

Cobalt. 

Copper. 

£ 

Ferric. 

Acetate  .   .    . 

W 

W 

W 

W 

W 

W 

W 

w 

W 

w 

W 

Arsenate     .    . 

a 

w 

a 

a 

a 

a 

a 

a 

a 

a 

a 

a 

Arsenite  .   .    . 

w 

E 

a 

a 

a 

A 

a 

a 

Benzoate    .   . 

w 

w 

w 

w 

w 

a 

w 

a 

Borate     .    .    . 

a 

w 

. 

a 

a 

w-a 

a 

a 

a 

a 

a 

a 

Bromid    .    .    . 

w 

W 

w-a 

w 

w-a 

w 

w 

w-i 

w 

w 

w 

w 

Carbonate  .    . 

a 

W 

,    , 

A 

A 

a 

A 

a 

A 

A 

A 

a 

Chlorate  .   .    . 

w 

w 

. 

W 

w 

w 

w 

w 

w 

w 

w 

w 

Chlorid    .    .    . 

w 

W2 

W-A6 

W 

W-A10 

W 

W 

W-I 

W 

W 

W 

W 

Chromate    .    . 

w 

a 

a 

a 

a 

w-a 

a 

a 

w 

w 

Citrate.  .    .    . 

w 

w 

. 

a 

. 

a 

w-a 

w 

w 

w 

w 

W 

Cyanid     .    .    . 

w 

. 

w-a 

. 

a 

w 

a 

a-i 

a 

a-i 

, 

Ferricyanid    . 

w 

w 

i 

I 

w 

Ferrocyanid  . 

w 

. 

w-a 

. 

. 

w 

'   ' 

i 

i 

i 

I 

Fluorid    .    .    . 

w 

W 

w 

a-i 

w 

w-a 

A 

w 

w-a 

a 

w-a 

w 

Formate  .   .    . 

w 

w 

t 

w 

w 

w 

w 

w 

w 

w 

w 

w 

Hydrate  .    .    . 

A 

W 

A 

W 

a 

a 

W-A 

A 

A 

a 

a 

A 

lodid    .... 

w 

W 

w-a 

w 

a 

W 

w 

w 

w 

w 

W 

w 

Mai  ate  .... 

w 

w 

w—  a 

w-a 

w 

Nitrate    .    .    . 

w 

W 

W 

W1'1 

w 

w 

W 

W 

W 

W 

W 

Oxalate   .    .    . 

a 

W 

a 

a 

a 

a 

A 

w-a 

A 

a 

a 

a 

Oxid  

A-I 

a7 

W 

a 

a 

W-A 

A-I 

A 

A 

a 

A 

Phosphate  .    . 

a 

w:! 

w-a 

w-a 

a 

a 

W-A 

a 

a 

a 

a 

a 

Silicate   .    .    . 

A-I 

a 

a 

a 

a 

a 

a 

a 

a 

Suc«cinate  .    . 

w  a 

w 

w-a 

w 

w-a 

w-a 

w-a 

w 

Sulfate    .    . 

W1 

W4 

a 

A 

w 

W 

W-I 

W-A" 

W13 

W 

W 

W 

Sulfid  .... 

a 

W 

A8 

W 

a 

A 

W-A 

a-i 

a 

A 

A 

A 

Tartrate  .    .    . 

w 

w5 

a9 

a 

a 

w-a 

a 

w 

w 

w 

w-a 

W14 

1(A12)(NH4)2(S04)4=W;  (A12)K2(S04)4=W.  2 
Pt(NH4)Cl5=W-I.  3HNa(NH4)PO4=W;  Mg(NH4)PO4=A.  4Fe- 
(NH4)2(S04)2=W;  Cu(NH4)2(SO4)2=W.  5C4H4O6K(NH4)=W.  6Sb- 
OC1=A.  7Sb2O3=soluble  in  HC1,  not  in  HNO3.  8Sb2S3=sol.  in  hot 
HC1,  slightly  in  HNO3.  9C4H4O6K(SbO)=W.  10BiOCl  =A.  n(BiO) 
NO3=A.  12(Cr2)K2(SO4)4=W.  13CoS=easily  sol.  in  HNO3,  very 
slowly  in  HOI.  14(C4H406)4(Fe2)K2=W. 

(636) 


SOLUBILITIES 


637 


TABLE   I.—  SOLUBILITIES.—  Continued. 
FEESENIUS. 

W  or  w  =  soluble  in  EbO.  A  or  a  =  insoluble  in  H2O;  soluble 
in  HC1,  HNO3,  or  aqua  regia.  I  or  i  =  insoluble  in  H^O  and  acids. 
W-A  =  sparingly  soluble  in  H^O,  but  soluble  in  acids.  W-I  =  spar- 
ingly soluble  in  H2O  and  acids.  A-I  =  insoluble  in  H20,  sparingly 
soluble  in  acids.  Capitals  indicate  common  substances. 


j 

Magnesium. 

Manganese. 

co 

6 

3 

Mercuric. 

5 

% 

Potassium. 

I 

33 

I 

Strontium. 

Stannous. 

Stannic. 

1 

55 

Acetate    .    . 

W 

W 

W 

w-a 

W 

w 

W 

w 

W 

W 

w 

W 

W 

Arsenate 

a 

a 

a 

a 

a 

a 

w 

a 

W 

a 

a 

a 

. 

Arsenite  . 

a 

a 

a 

a 

a 

a 

w 

a 

w 

a 

a 

Benzoate     . 

a 

w 

w 

a 

w-a 

w 

w-a 

w 

Borate  .  .    . 

a 

w-a 

a 

a 

W 

a 

W 

a 

a 

a 

Bromid  .  .    . 

w-i 

w 

w 

a-i 

w 

w 

W 

a 

W 

w 

w 

Carbonate    . 

A 

A 

A 

a 

a 

A 

w 

a 

W 

A 

. 

A 

Chlorate  .    . 

w 

w 

w 

w 

w 

w 

w 

w 

w 

w 

w 

w 

Chlorid  .  .    . 

W-I 

W 

W 

A-I 

W16 

W 

w° 

I 

W 

W 

W 

W 

W 

Chromate  .  . 

A-I 

w 

w 

a 

w-a 

a 

w 

a 

w 

w-a 

a 

. 

w 

Citrate  .  .    . 

a 

w 

a 

a 

w-a 

w 

w 

a 

W 

a 

w-a 

Cyanid  . 

a 

w 

a 

W 

a-i 

W 

i 

w 

w 

a 

Ferricyanid 

w-a 

w 

i 

.    . 

i 

w 

i 

w 

.    . 

a 

Ferrocyanid 

a 

w 

a 

.    . 

i 

w 

i 

w 

w 

. 

a-i 

Fluorid  .  .    . 

a 

a-i 

a 

w-a 

w-a 

w 

w 

w 

a-i 

w 

w 

w-a 

Formate  .    . 

w-a 

w 

w 

w 

w 

w 

w 

w 

w 

w 

w 

. 

w 

Hydrate   .    . 

a 

A 

a 

a 

W 

.    . 

W 

w 

a 

a 

a 

lodid.  .    .    . 

W-A 

w 

w 

A 

A 

w 

W 

i 

w 

w 

w 

w 

w 

Malate  •  .    . 

w-a 

w 

w 

a 

w-a 

w 

w-a 

w 

w 

w 

w 

w 

Nitrate  .  .    . 

W 

w 

w 

W 

W 

W 

W 

W 

W 

W 

, 

w 

Oxalate-  .    . 

a 

a 

w-a 

a 

a 

a 

W 

a 

W 

a 

a 

w 

a 

Oxid  ... 

A 

A 

A15 

A 

A 

A 

w 

a 

W 

W 

a 

A-I 

A 

Phosphate  . 

a 

a3 

a 

a 

a 

a 

w 

a 

W 

a 

a 

a 

a 

Silicate    .    . 

a 

a 

a 

a 

W 

. 

W 

a 

a 

Succinate.  . 

a 

w 

w 

a 

w-a 

w 

w 

a 

w 

w-a 

a 

w-a 

Sulfate  .  .    . 

A-I 

W 

W 

w-a 

W17 

W 

W12 

W-A 

W 

I 

w 

W 

Sulfid    .    .    . 

A 

a 

a 

a 

A18 

A19 

W 

a21 

W 

w 

a22 

A22 

A23 

Tartrate  .    . 

a 

w-a 

w-a 

w-a 

a 

a 

w 

a 

w 

a 

a 

a 

15MnO2=sol.  in  HC1;  insol.  in  HN03.  16Mercurammouium 
chlorid=A.  17  Basic  sulfate=A.  18HgS  =  insol.  in  HC1  and  in 
HNO3,  sol.  in  aqua  regia.  19  See  13.  20PtKCl5=W-A.  21Only 
soluble  in  HNO3.  22  Sn  sulfids  =  sol.  in  hot  HC1;  oxidized,  not 
dissolved,  by  HN03.  Sublimed  SnCU  only  sol.  in  aq.  regia.  23  Easily 
sol.  in  HNO3,  difficultly  in  HC1. 

Au2S  =  insol.  in  HC1  and  in  HNO3,  sol.  in  aq.  regia.  AuBr3, 
AuCla,  and  Au(CN)3  =  w;  AuI3  =  a  PtS2  =  insol.  in  HC1,  slightly 
sol.  in  hot  HNO3;  sol.  in  aq.  regia.  PtBr4,  PtCU,  Pt(CN)4, 
Pt(NO3)4,  Pt(G\>04)2,  Pt(S04)a  =  w;  PtO2  =  a;  PtLi  =  i. 


638 


MANUAL    OF    CHEMISTRY 

TABLE   II.— WEIGHTS    AND    MEASURES. 
MEASURES    OF    LENGTH. 


1  millimeter 

=  0.001  meter  =      0.0394  inch. 

1  centimeter 

=  0.01        "      =      0.3937     " 

1  decimeter 

=  0.1          "      =      3.9371  inches. 

1  METER 

=    39.3708       " 

1  decameter 

=      10  meters  =    32.8089  feet. 

1  hectometer  =    100       "        =328.089       " 

1  kilometer 

=  1000                =      0.6214  mile. 

Inch. 

Millimeters. 

Inches.              Centimeters.                  Inches.              Centimeters. 

Jj 

= 

0.3819 

2        =          5.08                           9        = 

22.86 

JL. 

•  — 

0.7637 

3        =          7.62                         10        = 

25.40 

A 

= 

1.5875 

4        =        10.16                         11        = 

27.94 

-|- 

= 

3.175 

5        =         12.70                         12        = 

30.48 

i 

— 

6.35 

6        =        15.24                         18        = 

45.72 

i 

— 

12.7 

V        =         17.78                         24        = 

60.96 

1 

= 

25.4 

8        =        20.32                         36        = 

91.44 

MEASURES    OF    CAPACITY. 

1 

milliliter  = 

1 

c.c.  =  0.001  liter  =      0.0021  U.  S.  pint. 

1 

centiliter  = 

10 

"    =  0.01       "     =      0.0211 

1 

deciliter    = 

100 

"    =  0.1         "     =      0.2113 

1 

LITER      =  1000 

=      1.0567              quart. 

1 

decaliter 

=      10  liters  =      2.6418             galls. 

1 

hectoliter 

=    100     "      =    26.418 

1 

kiloliter 

=  1000     "      =  264.18 

M. 

c.c. 

m. 

c.c.                            m.              c.c.                             •pi  5 

C.C. 

1  = 

0.06 

26  =  1. 

60 

51  =      3.14 

•*•  *  «^ 

5 

=  147.81 

2  = 

0.12 

27  =  1. 

66 

52  =      3.20 

6 

=  177.39 

3  = 

0.19 

28  =  1. 

73 

53  =      3.26 

7 

=  206.96 

4  = 

0.25 

29  =  1. 

79 

54  =      3.32 

8 

=  236.53 

5  = 

0.31 

30  =  1. 

85 

55  =      3.39 

9 

=  266.10 

6  = 

0.37 

31  =  1. 

91 

56  =      3.46 

10 

=  295.68 

7  = 

0 

.43 

32  =  1. 

98 

57  =      3.52 

11 

=  325.25 

8  = 

0 

.49 

33  =  2.04 

58  =      3.58 

12 

=  354.82 

9  = 

0 

.55 

34  =  2. 

10 

59  =      3.64 

13 

=  384.40 

10  = 

0 

.62 

35  =  2. 

16 

60  =      3.70 

14 

=  413.97 

11  = 

0 

.68 

36  =  2. 

22 

15 

=  443.54 

12  = 

0.74 

37  =  2. 

28. 

1  =      3.70 

16 

=  473.11 

13  = 
14  = 

0 

0 

.80 
.86 

38  =  2. 
39  =  2. 

34 

40 

2  =      7'.39 
—     1  1   no 

O. 
1 

Litres. 
=       0.47 

15  = 

0 

.9^ 

40  =  2. 

46 

—  —  •     x  A  »i/y 
—      14.  7Q 

2 

=      0.95 

16  = 
17  = 

0 

1 

.99 
.05 

41  =  2. 
42  =2 

52 
58 

—  —          J.TC  •   i  «7 

5  =    18.48 
—     oo  iQ 

3 
4 

=      1.42 
=      1.89 

18  = 
19  = 
20  = 

.11 
.17 
.23 

43  =  2 
44  =  2 
45  =  2. 

66 

72 
77 

Ltu  .  .Lo 

7  =    25.88 
8=    29.57 

5 
6 

7 

=      2.36 

=      2.84 
=      3.31 

21  = 

.29 

46  =  2. 

84 

Fl^  • 

8 

=      3.79 

22  = 

.36 

47  =  2. 

90 

l"=    29.57 

9 

=      4.26 

23  = 

.42 

48  =  2 

96 

2  =    59.14 

10 

=      4.73 

24  = 

.48 

49  =  3. 

02 

3  =    88.67 

11 

=      5.20 

25  = 

1 

.54 

50  =  3. 

08 

4  =  118.24 

12 

=      5.67 

WEIGHTS    AND    MEASURES 


639 


WEIGHTS. 

1  milligram   =  0.001  gram    =  0.015  grain  Troy. 

1  centigram  =  0.01        "        =  0.154      " 

1  decigram    =0.1          "        =  1.543  grains    " 

1  GRAM  =  15.432      "         " 

1  decagram   =        10  grams  =  154.324      "        " 

lhectogram=      100      "       =  0.268  Ib. 

1  kilogram     =    1000      "      =  2.679  Ibs.         " 


Grains.  Grams. 

Grains.  Grams. 

Grains.  Grams. 

*s          Grflins 

6\  =  0.001 

21  =     .361 

47  =    3.046 

1=    31.103 

&  =  0.002 

22=     .426 

48  =    3.110 

2  =    62.207 

&  =  0.004 

23  =     .458 

49  =    3.175 

3  =    93.310 

i  =  0.008 

24  =     .555 

50  =    3.240 

4  =  124.414 

|  =  0.016 

25  =    .620 

51  =    3.305 

5  =  155.517 

£  =  0.032 

26  =     .685 

52  =    3.370 

6  =  186.621 

1  =  0.065 

27  =     .749 

53  =    3.434 

7  =  217.724 

2  =  0.130 

28  =    .814 

54  =    3.499 

8  =  248.823 

3  =  0.194 

29  =     .869 

55  =    3.564 

9  =  279.931 

4  =  0.259 

30  =     .944 

56  =    3.629 

10  =  311.035 

5  =  0.324 

31  =  2.009 

57  =    3.694 

11  =  342.138 

6  =  0.389 

32  =  2.074 

58  =    3.758 

12  =  373.250 

7  =  0.454 

33  =  2.139 

59=    3.823 

Lbs.           Kilos. 

8  =  0.518 

34  =  2.204 

60=    3.888 

1  ==      0.373 

9  =  0.583 

35  =  2.268 

3 

2  =      0.747 

10  =  0.648 

36  =  2.332 

1  =    3.888 

3  =      1.120 

11  =  0.713 

37  =  2.397 

2  =    7.776 

4  =      1.493 

12  =  0.778 

38  ==  2.462 

3  =  11.664 

5  =      1.866 

13  =  0.842 

39  =  2.527 

4  =  15.552 

6  =      2.240 

14  =  0.907 

40  =  2.592 

5  =  19.440 

7  =      2.613 

15  =  0.972 

41  =  2.657 

6  =  23.328 

8  =      2.986 

16  =  1.037 

42  =  2.722 

7  =  27.216 

9  =      3.359 

17  =  1.102 

43  =  2.787 

8  =  31.103 

10  =      3.733 

18  =  1.166 

44  =  2.852 

19  =  1.231 

45  =  2.916 

20  =  1.296 

46  =  2.980 

1  pound  Avdp 

.=  453.5925  gm. 

1  kilo 

=      2.2046  Ibs.  Avdp 

640 


MANUAL    OP    CHEMISTRY 


TABLE    III. 

WEIGHT    OP    ONE    CUBIC    CENTIMETER    OF    NITROGEN. 


728 

730 

732 

734 

736 

738 

740 

742 

f  10° 

1.1466 

1.1498 

1.1529 

1.1561 

.1593 

.1625 

1.1657 

1.1689 

CD 

11° 

1.1415 

1.1447 

1.1479 

1.1511 

.1542 

.1574 

1.1606 

1.1638 

3 

12° 

1.1364 

1.1396 

1.1428 

1.1459 

.1491 

.1523 

1.1554 

1.1586 

a 

13° 

1.1314 

1.1345 

1.1377 

1.1409 

.1440 

.1472 

1.1503 

1.1535 

14° 

1.1263 

1.1294 

1.1326 

1.1357 

.1389 

.1420 

.1452 

1.1483 

s 

15° 

1.1211 

1.1243 

1.1274 

1.1305 

.1337 

1.1368 

1.1399 

1.1431 

o 

16° 

1.1160 

1.1191 

1.1222 

1.1253 

.1285 

1.1316 

.1347 

1.1378 

.2 

17° 

1.1107 

1.1138 

1.1170 

1.1201 

.1232 

1.1263 

1.1294 

1.1325 

00 

18° 

1.1054 

1.1085 

1.1117 

1.1148 

.1179 

1.1209 

1.1241 

1.1272 

£ 

19° 

1.1001 

1.1032 

1.1063 

1.1094 

.1125 

1.1156 

1.1187 

1.1218 

,2 

20° 

1.0948 

1.0979 

1.1009 

1.1040 

.1071 

1.1102 

1.1133 

M164 

M 

CD 

21° 

1.0894 

1.0924 

1.0955 

1.0986 

.1017 

1.1047 

1.1078 

1.1109 

A 

22° 

1.0839 

1.0870 

1.0900 

1.0931 

.0961 

1.0992 

1.1023 

1.1053 

a 

CD 

23° 

1.0784 

1.0814 

1.0845 

1.0875 

.0906 

1.0936 

1.0967 

1.0997 

5 

24° 

1.0728 

1.0758 

1.0789 

1.0819 

.0849 

1.0880 

1.0910 

1.0940 

25° 

1.0671 

1.0701 

1.0732 

1.0762 

.0792 

1.0823 

1.0853 

1.0883 

728 

730 

732 

734 

736 

738 

740 

742 

744 

746 

748 

750 

752 

754 

756 

758 

10° 

1.1721 

1.1753 

1.1785 

1.1817 

1.1848 

1.1880 

1.1912 

1.1944 

CD 

11° 

1.1670 

1.1701 

1.1733 

1.1765 

1.1717 

1.1829 

1.1860 

1.1892 

t3 
OS 

12° 

1.1618 

1.1649 

1.1681 

1.1713 

1.1744 

1.1776 

1.1808 

1.1839 

b 

bfl 

13° 

1.1566 

1.1598 

1.1630 

1.1661 

1.1693 

1.1724 

1.1756 

1.1787 

'43 

14° 

1.1515 

1.1546 

1.1577 

1.1609 

1.1640 

1.1672 

1.1703 

1.1735 

§ 

15° 

.1462 

.1493 

1.1525 

1.1556 

1.1587 

1.1619 

.1650 

1.1681 

Q 

16° 

.1409 

1.1441 

1.1472 

1.1503 

.1534 

1.1566 

.1597 

1.1628 

fl 

17° 

.1356 

.1397 

1.1419 

1.1450 

.1481 

1.1512 

.1543 

1.1574 

03 

18° 

.1303 

.13,34 

1.1365 

1.1396 

.1427 

1.1458 

.1489 

.1520 

t 

19° 

.1248 

.1279 

1.1310 

1.1341 

.1372 

1.1403 

.1434 

1.1465 

& 

"S 

20° 

.1194 

1.1225 

1.1256 

1.1287 

.1318 

1.1348 

.1379 

1.1410 

21° 

.1139 

1.1170 

1.1201 

1.1231 

.1262 

1.1293 

.1324 

1.1354 

& 

22° 

.1084 

1.1115 

1.1145 

1.1176 

.1206 

1.1237 

.1268 

1.1298 

a 

<u 

23° 

.1028 

1.1058 

1.1089 

1.1119 

.1150 

1.1180 

.1211 

1.1241 

H 

24° 

1.0971 

1.1001 

1.1032 

1.1062 

.1092 

1.1123 

.1153 

1.1184 

.  25° 

1.0913 

1.0944 

1.0974 

1.1004 

1.1035 

1.1065 

1.1095 

1.1126 

744 

746 

748 

750 

752 

754 

756 

758 

Barometric  pressure  in  millimeters. 


TABLE    III 


641 


TABLE   III.— Continued. 
WEIGHT    OP    ONE    CUBIC    CENTIMETER    OP    NITROGEN. 


760 

762 

764 

766 

768 

770 

772 

774 

r  10° 

1.1976 

1.2008 

1.2040 

.2072 

1.2104 

1.2136 

1.2167 

1.2199 

d> 

11° 

1.1924 

1.1956 

1.1988 

.2019 

1.2051 

1.2083 

1.2115 

1.2147 

'S 

12° 

1.1871 

1.1903 

1.1934 

.1966 

1.1998 

1.2029 

1.2061 

.2093 

2 

&D 

13° 

.1819 

1.1851 

1.1882 

.1914 

1.1945 

1.1977 

1.2008 

.2040 

.-H 

14° 

.1766 

1.1798 

1.1829 

.1861 

1.1892 

1.1923 

1.1955 

.1986 

3 

9) 

15° 

.1713 

1.1744 

1.1775 

.1807 

1.1838 

1.1869 

1.1901 

.1932 

0 

16° 

.1659 

1.1691 

1.1722 

.1753 

1.1784 

1.1816 

1.1847 

.1878 

fl 

17° 

1.1605 

1.1636 

1.1667 

.1699 

1.1730 

1.1761 

1.1792 

.1823 

CO 

18° 

1.1551 

1.1582 

1.1613 

.1644 

1.1675 

1.1706 

1.1737 

1.1768 

o> 

N 

19° 

1.1496 

1.1527 

.1558 

.1589 

1.1620 

1.1650 

1.1681 

1.1712 

0 

•£ 

20° 

1.1441 

1.1472 

.1502 

1.1533 

1.1564 

1.1595 

1.1626 

1.1657 

g 

21° 

1.1385 

1.1416 

.1446 

1.1477 

1.1508 

1.1539 

1.1569 

1.1600 

P, 

22° 

1.1329 

1.1359 

1.1390 

1.1421 

1.1451 

1.1482 

1.1512 

1.1543 

1 

23° 

1.1272 

1.1302 

.1333 

1.1363 

1.1394 

1.1424 

1.1455 

1.1485 

EH 

24° 

1.1214 

1.1244 

.1275 

1.1305 

1.1336 

1.1366 

1.1396 

1.1427 

L  25° 

1.1156 

1.1186 

.1216 

1.1247 

1.1277 

1.1307 

1.1338 

1.1368 

760 

762 

764 

766 

768 

770 

772 

774 

776 

778 

780 

782 

784 

786 

788 

790 

10° 

1.2231 

1.2263 

1.2295 

1.2327 

1.2359 

.2391 

1.2423 

1.2454 

CD 

11° 

1.2178 

1.2210 

1.2242 

1.2274 

1.2306 

.2337 

1.2369 

1.2401 

? 

12° 

1.2124 

1.2156 

1.2188 

1.2219 

1.2251 

.2283 

1.2314 

1.2346 

& 

13° 

1.2072 

1.2103 

1.2135 

1.2166 

.2198 

2229 

1.2261 

1.2293 

14° 

1.2018 

1.2049 

1.2081 

1.2112 

.2144 

^2175 

1.2207 

1.2238 

0 
0 

15° 

1.1963 

1.1995 

1.2026 

1.2057 

.2089 

.2120 

.2151 

1.2183 

o 

16° 

1.1909 

1.1942 

1.1973 

1.2004 

.2035 

.2067 

.2098 

1.2129 

•^ 

17° 

1.1854 

1.1885 

1.1916 

1.1947 

.1979 

1.2010 

.2041 

1.2072 

GO 

18° 

1.1799 

1.1831 

1.1862 

1.1893 

1.1924 

1.1955 

.1986 

1.2017 

£ 

19° 

1.1743 

1.1774 

1.1805 

1.1836 

1.1867 

1.1898 

.1929 

1.1960 

3 

4* 

20° 

1.1687 

.1718 

1.1749 

1.1780 

1.1811 

1.1841 

.1872 

1.1903 

E 

4) 

21° 

1.1031 

.1661 

1.1692 

1.1723 

1.1754 

1.1784 

.1815 

1.1846 

& 

22° 

1.1574 

.1604 

1.1635 

1.1665 

1.1696 

1.1727 

.1757 

1.1788 

a 

<D 

23° 

1.1516 

.1546 

1.1577 

1.1607 

1.1638 

1.1668 

.1699 

1.172!) 

EH 

24° 

1.1457 

.1488 

1.1518 

1.1548 

1.1579 

1.1610 

.1640 

1.1671 

25° 

1.1399 

.1429 

1.1459 

1.1489 

1.1520 

1.1550 

.15bO 

1.1610 

776 

778 

780 

782 

784 

786 

788 

790 

Barometric  pressure  in  millimeters. 


41 


INDEX. 


Abram,  538. 

Abrin,  495. 

Absorption,  coefficient  of,  562. 

Acenaphthalene,  440,  445. 

Acetal,  244,  261,  321. 

Acetals,  261. 

Acetaldehyde,  257. 

hydrazoiie,  360. 
Acetamid,  328,  335,  340,  345,  346,  348,  351, 

361. 

Acetaraidin,  335. 
Acetanilid,  400,  421. 

methyl,  422. 

sodium,  422. 
Acetenyl  benzene,  387. 
Acetins,  253. 

Acetoacetic  ester,  298,  313. 
Acetochlorhydrose,  320,  410. 
Acetol,  263,  404. 

salicylate,  404. 
Acetonsemia,  262. 
Acetonamins,  360. 

Acetone,  160,   262,  279,  298,  323,  360,  361, 
372,  373,  615,  616. 

diethyl  sulfone,  323. 

dimethyl  sulfone,  323. 

phenylhydrazone,  430. 
Acetones,  261. 

Acetonitril,  335,  340,  346,  348,  360. 
Acetophenone,  387,  400. 

oxim,  400. 

Acetophenyl  hydrazid,  431. 
Acetoxim,  360,  361. 
Acetoxims,  361. 
Acettoluids,  422. 
Acetyl  benzene,  400. 

benzoyl-aconin,  491. 

chlorid,  258,  311,  320,  333,  340,  341,  346, 
351,  414. 

cyanid,  341. 

haloids,  400. 

hydrid,  257. 

hydroxid,  278,  279. 

morphins,  484. 

urea,  351. 
Acetylene,  189,  243,  337,  368,  370,  378,  387. 

alcohols,  372. 

aldehydes,  373. 

mercuric  chlorid,  370. 

series,  229,  370. 
Acetylids,  370. 
Achrob'dextrins,  276. 
Acid  (See  also  acids). 

Acid,  acetic,  217,  238,  244,  258,  262,   279, 
301,  361,  372,  373,  374,  516. 

acetoacetic,  293,  298. 

acetobenzoic,  408. 

acetohydroxamic,  335. 

acetyl-amidoacetic,  362. 

acetyl-pyrophosphorous,  119. 

aconitic,  297,  376. 


Acid,  acrylic,  293,  372,  373,  374. 

adipic,  289. 

Acid-albumens,  498,  604,  518,  519. 
Acid,  allanturic,  354. 

allophanic,  351. 

alloxanic,  351,  353. 

alpha-oxycaproic,  293. 

alpha-oxyisobutyric,  290,  291. 

alpha-oxypropionic,  290,  292,  298. 

amidoacetic,    332,   361,    362,    363,    366, 
526. 

amidobutyric,  363,  456. 

amidocarbonic,  335. 

amidoethylsulfuric,  366. 

amidoformic,  346,  362. 

amidoglutaric,  366. 

amidoisethionic,  366,  377,  526. 

amidoisobutylacetic,  364. 

amidolactic,  362. 

amidomalonic,  361,  366. 

amidophenylacetic,  424. 

amidosuccinic,  366. 

amidothiolactic,  367. 

amygdalic,  410. 

amylsulfuric,  250. 

angelic,  374. 

anilidoacetic,  425. 

anilidopropionic,  424. 

anilin-disulfanilic,  420. 

anilpyroracemic,  426. 

anthranilic,  401,  424. 

anthraquinone  monosulfonic,  445. 

antimonic,  137,  138. 

antitartaric,  295. 

arachic,  284. 

arsenic,  126,  128. 

arsenous,  125,  126. 

aspartic,  366,  578. 

atropic,  402,  408,  475. 

auric,  146. 

azelaic,  289. 

azulmic,  342. 

barbituric,  352. 

benzene  m-dicarboxylic,  402. 

benzene  monosulfonic,  415. 

benzene  o-dicarboxylic,  402. 

benzene  p-dicarboxylic,  402. 

benzene  sulfonic,  385. 

benzene  trisulfonic,  415. 

benzhydroxamic,  426. 

benzoic,  363,  365,  385,  386,  388,  397,  399, 
401,  403,  408,  414,  425,  437,  438,  491. 

benzoylacetic,  408. 

benzoylamidoacetic,  425. 

benzoylformic,  408. 

benzoylglycollic,  409. 

benzoylmalonic,  409. 

benzoylpyroracemic,  409. 
rltartronic,  408. 


benzyl 

beta-monocarbopyridic,  474. 
beta-oxybutyric,  293,  298. 


(643) 


644 


INDEX 


Acid,  beta-oxypropionic,  293. 

bilianic,  526. 

biliverdic,  529. 

bismuthic,  163. 

boric,  140. 

brassylic,  289. 

bromic,  88. 

bromoprotocatechuic,  406. 

butylformic,  282. 

butyric,  279,  281,  288,  478,  516. 

caffeic,  407. 

caffetannic,  407. 

camphoglucuronic,  594. 

camphoric,  437. 

camphoronic,  289,  437. 

capric,  283. 

caproic,  283. 

caprylic,  283. 

carbamic,  346,  362. 

carbanilic,  426. 

carbazotic,  418. 

carbolic,  389. 

carbomandelic,  408. 

carbonic,  278,  291,  342. 

carminic,  411. 

cerotic,  315. 

chelidonic,  458. 

chlorethyl  sulfuric,  367. 

chloric,  86. 
Acid  chlorids,  241. 
Acid,  cholesteric,  526,  529. 

choleic,  526. 

cholic,  526,  527,  530,  537. 

cholonic,  527. 

cholylic,  526. 

chondroitin-sulfuric,  505,  595,  603. 

chromic,  147,  148. 

chrysophanic,  445. 

cinchomeronic,  461,  480. 

cinchoninic,  480,  481. 

cinnamic,  387,  398,  400,  402,  438. 

citraconic,  297,  376, 

citric,  279,  297,  376. 

comenic,  458. 

coumalic,  376. 

crotonic,  373,  374. 

cumene  sulfonic,  392. 

cumic,  401. 

cyanic,  342. 

cyanoacetic,  288. 

cyanopropionic,  288. 

cyanuric,  342,  349,  355. 

decylic,  283. 

dehydrocholic,  526. 

delphinic,  282. 

deoxycholic,  526. 

dextrocamphoric,  437. 

dextrolactic,  293. 

dextronic,  294. 

dextrotartaric,  295. 

dialuric,  352. 

diamidoacetic,  365. 

diamidocaproic,  499. 

diamidopropionic,  365. 

diamidovalerianic,  365. 

diazobenzene  sulfonic,  502. 

dibromobenzoic,  406. 

dibromopropionic,  365. 

dichloracetic,  280,  297. 

dichromic,  148. 

digallic,  406. 

dihydrocyanic,  345. 


Acid,  diiodo-phenol  monosulfonic,  410. 
diiodo-resorcinol  monosulfonic,  416. 
dimalonic,  277,  289. 
dimethoxybenzoic,  488. 
dimethoxyphthalic,  488. 
dimethylmalonic,  285. 
dioxycinnamic,  407. 
dioxymalonic,  298. 
diphenic,  444. 
disulfanilic,  420. 
dithiocarbamic,  350. 
dithio-diamido-dilactic,  367. 
dithionic,  96. 
elaidic,  375. 
ellagic,  538. 

erythroglucic,  254,  293. 
erythritic,  293. 
ethalic,  284. 
ethidene  lactic,  292. 
ethidene  malonic,  376. 
ethidene  propionic,  374. 
ethyldiacetic,  262. 
ethylmalonic,  285. 
ethylnitrolic,  325. 
ethylsulfinic,  322. 
ethylsulfonic,  313. 
ethylsulfuric,   301,  310,   312,  313,  322, 

368,  369. 

ethylene  lactic,  293,  373. 
ethylene  succinic,  289. 
fellic,  527. 
ferric,  152. 
fluorenic,  441. 
formic,  242,  262,  278,  279,  292,  296,  297, 

340,  357,  372,  373. 
fulminic,  342,  343. 
fulminuric,  343. 
fumaric,  295. 
furane  carboxylic,  455. 
f urfurane  monocarboxylic,  297. 
gadinic,  319. 
galactonic,  269. 
gallic,  395,  406. 
gallotannic,  406. 
gammaquinolin  carboxylic,  481. 
gentisinic,  405. 
glacial  phosphoric,  121. 
gluconic,  268,  294. 
glucovanillic,  411. 

glucuronic,  297,  299,  454,  465,  594,  615. 
glutaconic,  376. 
glutaminic,  366. 
glutaric,  285,  288. 
glyceric,  293. 

glycerophosphoric,  317,  319. 
glycocholic,  363,  527. 
glycolamic,  363. 

glycollic,  239,  254,  257,  290,  292,  363. 
glycoluric,  351. 
glycosuric,  406,  606. 
glyoxylic,  239,  254,  297,  298,  353. 
graphitic,  141. 
guaiacol  sulfonic,  416. 
guanylnucleic,  507. 
heptylic,  283. 
hesperetic,  413. 

hexahydro-tetroxybenzoic,  437. 
hippuric,  354,  363,  401,   425,  531,  544, 

588. 

homogentisinic,  406. 
homoprotocatechuic,  406. 
hydantoic,.  351. 


INDEX 


645 


Acid,  hydracrylic,  293,  362. 
hydrazoic,  104,  106. 
hydrindic,  466. 
hydriodic,  89. 
hydrobromic,  87. 
hydrochloric,  83,  515,  520. 
hydrocinnamic,  403. 
hydrocyanic,   257,    278,   290,    337,   340, 

341,  347,  363,  370,  378,  398,  410. 
hydrofluoric,  79. 
hydrofluosilicic,  144. 
hydronitroprussic,  345. 
hydroparacoumaric,  405. 
hydroplatinocyanic,  345. 
hydroquinone  carboxylic,  405. 
hydrosulfuric,  92. 
hydrosulfurous,  97. 
hypobromous,  87. 
hypochlorous,  86. 
hypogseic,  374. 
hyponitrous,  108,  109. 
hypophosphoric,  119,  121. 
hypophosphorous,  11.9. 
hyposulfurous,  96,  97. 
indigo  disulfonic,  467. 

monosulfonic,  467. 
indoxylic,  465. 
indoxyl-sulfuric,  465,  590. 
iodic,  90. 

iodopropionic,  364,  373. 
isatoic,  466. 
isatropic,  475. 
isethionic,  321,  322,  367. 
isobutylformic,  282. 
isobutyric,  282. 
isocrotonic,  374. 
isocyanic,  343. 
isoferrulic,  413. 
isonicotinic,  461,  469. 
isophthalic,  402. 
isopropylacetic,  282. 
isopropylformic,  282. 
isosaccharic,  455. 
isostrychnic,  482. 
isosuccinic,  285,  288. 
isovaleric,  238,  250,  282. 
isovanillic,  405. 
itaconic,  289,  297,  376. 
lactic,  266,  290,  292,  362,  373,  484,  516, 

523. 

Isevolactic,  293. 
IsDvotartaric,  295,  296. 
lauric,  283. 
laurostearic,  283. 
leucic,  293. 

linoleic,  318,  374,  375. 
lithic,  354. 
lithofellic,  538. 
maleic,  375. 

malic,  288,  295,  296,  366,  375,  412. 
malonic,  288,  352,  359. 
maltonic,  294. 
mandelic,  408. 
mannonic,  255,  294. 
mannosaccharic,  255,  294,  297. 
margaric,  284. 
meconic,  458,  459,  484. 
meconinic,  407. 
mesaconic,  376. 
mesotartaric,  295,  296,  375. 
mesoxalic,  298,  354. 
metaboric,  140. 


Acid,  metahemipinic,  488. 
metanitrous,  109. 
metantimonic,  137,  138. 
metantimonous,  138. 
metaphosphoric,  119,  121. 
metaphosphorous,  119. 
metarsenic,  126,  127. 
metarsenous,  126. 
metastannic,  165. 
metatoluic,  402. 
metatungstic,  145. 
methacrylic,  374. 
methylcrotonic,  374. 
methylethylacetic,  283. 
methylfumaric,  376. 
methylguanidinacetic,  336. 
methylindole  carboxylic,  465. 
methylmaleic,  376. 
methylmalonic,  288. 
methylsuccinic,  285,  289. 
methylsulfuric,  299. 
methylenesuccinic,  376. 
monobromopropionic,  373 
monobromosuccinic,  376. 
monochloracetic,    280,    288,    292,   332, 

362,  364. 

mucic,  269,  272,  275,  297,  455. 
muriatic,  83. 
myristic,  283. 
myronic,  413. 
morintannic,  393,  407. 
morrhuic,  493. 
naphthalene  sulfonic,  443. 
naphthalic,  445. 
naringenic,  413. 

nicotinic,  461,  469,  474,  478,  493. 
nitric,  103,  110. 
nitroacetic,  361. 
nitrohydrochloric,  84. 
nitrosonitric,  111. 
nitrosulfuric,  108. 
nitrous,  103,  109. 
nonylic,  283. 
octylic,  283. 
oenanthylic,  283. 
oleic,  282,  284,  374. 
opianic,  408,  467,  489. 
ornithuric,  365. 
orcellinic,  406. 

orthoamidobenzoic,  401,  424. 
orthoamidobenzoylformic,  424,  466. 
orthoamidocinnamic,  468. 
orthoamidomandelic,  424,  466. 
orthoamidophenylacetic,  424. 
orthoantimonic,  137. 
orthoarsenic,  126. 
orthocarbonic,  292. 
orthonitrocinnamic,  464,  466. 
orthonitrophenylacetic,  466. 
orthophenyl  sulfonic,  416. 
orthophosphoric,  120. 
orthotoluic,  402,  407. 
orthovinylbenzoic,  402. 
orthoxybenzoic,  404. 
orthoxyparatoluic,  405. 
osmic,  145. 
oxalic,  239,  254,  255,  262,  272,  275,  278, 

279,    285,    286,  292,    293,  296,  301, 

302,  354,  355,  594. 
oxaluric,  352,  589. 
oxaniic,  346. 
oxanilic,  423,  425. 


646 


INDEX 


Acid,  oxyacetic,  292. 

oxybutyric,  293,  363,  611,  615. 

oxyformic,  291. 

oxyglutaric,  288.  295, 

oxymalonic,  295. 

oxyphenic,  279,  393. 

oxypropionic,  373. 

oxyproteic,  595. 

oxy salicylic,  394. 

oxysuccinic,  295. 

palmitic,  284,  319,  374. 

para-amidobenzene  sulfonic,  420. 

parabanic,  352,  355. 

paraeoumaric,  413. 

paraisopropylbenzoic,  401. 

paralactic,  293,  544. 

paraoxyhydratropic,  413. 

paraoxyphenylacetic,  405. 

paraoxyphenylglycollic,  405. 

paraoxyphenylpropionic,  405. 

parasorbic,  375. 

paratartaric,  295. 

paratoluic,  402. 

pelargonic,  283. 

pentathionic,  96. 

pentoxypimelic,  297. 

pepsohydrochloric,  517,  519. 

perbromic,  88. 

perchloric,  86. 

periodic,  90. 

persulfuric,  96,  100. 

phenanthrene  carboxylic,  442. 

phenyl acetic,  401. 

phenylacrylic,  475. 

phenylamidopropionic,  424. 

phenylbetaoxypropionie,  403. 

phenylglyceric,  408. 

phenylglycollic,  408. 

phenylhydracrylic,  475. 

phenylisocrotonic,  440,  443. 

phenylmalonic,  402. 

phenylpropiolic,  403. 

phenylpropionic,  403. 

phenylsulfuric,  589. 

phloretic,  314. 

phocenic,  282. 

phcenicin  sulfonic,  407. 

phosphatic,  121. 

phosphoglyceric,  595. 

phosphomolybdic,  145. 

phosphoric,  119,  120. 

phosphorous,  87,  119,  120. 

phosphosarcic,  595. 

phosphotungstic,  145. 

phthalamic,  424. 

phthalic,  402,  407,  408,  409,  440,  446. 

picric,  404,  418,  439,  482. 

pimelic,  289,  404. 

piperic,  403,  475. 

pivalic,  283. 

plumbic,  158. 

propargylic,  375. 

propenyl  pentacarboxylic,  277,  289. 

propiolic,  375. 

propionic,  279,  281,  288,  292. 

propyl acetic,  282. 

propylformic,  281. 

protocatechuic,  405,  406,  407. 

prussic,  337. 

pseudouric,  352,  358,  359. 

purpuric,  354. 

pyridin  carboxylic,  480. 


Acid,  pyridin  tartronic,  478. 

pyridin  tricarboxylic,  488. 

pyroantimonic,  138. 

pyroarsenic,  126,  127. 

pyroarsenous,  126. 

pyrobismuthic,  163. 

pyroboric,  140. 

pyrocholesteric,  526. 

pyrogallic,  395. 

pyroligneous,  279. 

pyromucic,  297,  455. 

pyrophosphoric,  119.  121. 

pyrophosphorous,  119. 

pyroracemic,  292,  298,  426. 

pyrosulfuric,  96,  100. 

pyrotartaric,  288,  289,  296. 

pyruvic,  296,  298. 

quercitannic,  407. 

quinic,  394,  397,  437,  478,  481. 

quinolinic,  461. 

quinotannic,  407,  478. 

quinovic,  413,  478. 

racemic,  268,  295,  296,  375. 
Acid  reaction,  41. 
Acid,  rheic,  445. 

ricinoleic,  375. 

rocellic,  289. 

rosolic,  390,  395. 

saccharic,  272,  273,  275. 

salicylic,  389,  398,  402,  404,  414,  424. 

salicylous,  399. 

salicyl  sulfuric,  416. 
Acid  salts,  43,  52. 
Acid,  sarcolactic,  293. 

sebacic,  289,  374. 

silicotungstic,  145. 

skatoleacetic,  465. 

sorbic,  375. 

sozolic,  416. 

stannic,  165. 

stearic,  284,  319. 

strychnic,  482. 

suberic,  289. 

succinamic,  347. 

succinic,  242,  285,  288,  295,  296,  3/6. 

sulfanilic,  420. 

sulfhydric,  92. 

sulfindigotic,  467. 

sulfindylic,  467. 

sulfocarbamic,  350. 

sulfocyanic,  343. 

sulfovinic,  300,  301,  312,  313. 

sulfothiocarbonic,  324. 

sulfuric,  96,  97,  103. 

sulfurous,  95,  96,  97,  103. 

tartaric,  246,  554,  266,  267,  279,  295,  298. 

tartronic,  295,  343. 

taurocarbamic,  307,  531,  595. 

taurocholic,  366,  527,  536,  537,  603. 

terebic,  437. 

terephthalic,  402. 

terpenylic,  437. 

tetraboric,  140. 

tetrathionic,  96. 

tiglic,  374. 

thioacetic,  321,  323. 

thiobenzoio.  415. 

thiocarbamie,  350. 

thiocarbonic,  342. 

thiocyanic,  342,  343. 

thiooxy  arsenic,  12(5. 

•  thiosulfuric,  96,  100,  322. 


INDEX 


647 


Acid,  triazoacetic,  105. 

tricarballylic,  277,  289,  376. 
trichloracetic,  259,  280. 
trichromic,  148. 
tricyanic,  342. 
trihydrocyanic,  345. 
trimethylacetic,  283. 
trimethyltricarballylic,  289,  437. 
trinitrophenic,  418. 
trioxycholesteric,  530. 
triphenylraethane-o-carboxylic,  449. 
trithiocarbonic,  324. 
trithionic,  96. 
tropic,  402,  408,  475. 
tropin  carboxylic,  477. 
uric,  342,  348,  352,  353,  354,  356,  358, 
359,  363,  462,  531,  544,  569,  578,  586. 
urochloralic,  594. 
uroleucic,  406. 
urous,  356. 

valerianic,  250,  279,  282. 
vanillic,  399,  405. 
veratric,  394,  405,  488,  491. 
xanthic,  356. 
Acidism,  565,  615. 
Acids,  42,  46,  65  (see  also  Acid), 
acetic  series,  277. 
acetylene  moncarboxylic,  375. 
alcohol,  277,  289,  298. 
aldehyde,  277,  285,  291,  297,  429. 

carboxylic,  407. 

ketonic,  298. 
alkyl  benzoic,  401. 

dithiocarbamic,  343. 
amic,  346,  347,  361,  425. 
amido,  351.  361,  416,  499,  500,  519,  577. 

acrylic,  499. 

butyric,  364. 

caproic,  364. 

cinnamic,  424. 

phenyl,  423,  424. 

propionic,  362,  364. 

valerianic,  364. 
anil,  426. 
anilic,  425. 
anilido,  423,  425. 
anthracene  carboxylic,  445. 
aromatic,  aldehyde,  408. 

alcohol  carboxylic,  407. 

amic,  423. 

amido,  416,  419,  423. 

carboxylic,  400. 

dioxyalcohol,  498. 

ketone,  408. 

nitro,  419. 

sulfonic,  401. 
arsenic,  126. 
basicity  of,  42. 
benzene  carboxylic,  440. 

disulfonic,  415. 
benzoic  series,  400. 
benzoylbenzoic,  449. 
benzylalcohol,  408. 
biliary,  526. 
bromobenzoic,  404. 
camphoric,  437. 
caproic,  283,  365. 
carbopyridic,  459. 
carboxylic,  238,  239,  256,  277,  442. 
cresylic,  391. 
crotonic,  374. 
cyano-fatty,  362. 


Acids,  diamido  caproic,  366. 

dicarboxylic,  366. 

fatty,  365. 
diatropic,  403. 
dicarboxylic,  278,  285. 
diketone  monocarboxylic,  298 
dimethyluric,  357,  358. 
dioxybenzoic,  406,  406. 
dioxydicarboxylic,  295. 
dioxyethylene  succinic,  295. 
diolefln  monocarboxylic,  293,  375. 
dioxyphenyl,  406. 
dioxytoluic,  406. 

diphenylmethane  carboxylic,  449. 
fatty,  277,  373,  501. 

amido,  361,  362. 

cyano,  285,  362. 

haloid,  285. 

monochloro,  362. 
fluorene,  carboxylic,  445. 
glyceric,  293. 
glycocholic,  526. 
gluconic,  294. 
hexylic,  283. 
hydroaromatic,  436,  437. 
hydrophthalic,  402. 
hydroxamic,  334,  335,  426. 
indene  carboxylic,  445. 
indigo  sulfonic,  467. 
indole  carboxylic,  465. 
isatropic,  403. 

ketone,  277,  291,  298,  407,  426,  429. 
lactic,  292,  362. 
leucic,  365. 
mannonic,  294,  297. 
mannosaccharic,  297. 
metallohydrocyanic,  344. 
methyluric,  358. 
monocarboxylic,  aromatic,  400. 
monohalogen  fatty,  373. 
monoketone  monocarboxylic,  298. 
monoxydicarboxylic,  294. 
naphthalene  carboxylic,  445. 
naphthoic,  445. 
naphthol  carboxylic,  445. 

sulfonic,  443. 

naphthylamin  sulfonic,  446. 
naphthyl  fatty,  445. 
nitrilic,  341. 
nitro  (organic),  361,  362. 

benzoic,  419,  424. 

cinnamic.  403. 
nitrolic,  325. 
nitrosopropionic,  364. 
nucleic,  506,  507,  548. 
olefln  dicarboxylic,  375. 

monocarboxylic,  285. 

tricarboxylic,  376. 
oleic,  373. 
ortho,  120. 

oxalic  series,  277,  285. 
oxy,  314. 

acetic,  290,  373. 

aldehyde,  299. 

benzoic,  404. 

butyric,  290,  293. 

caproic,  365. 

diolefin  monocarboxylic,  376. 

ketone,  299. 

methylbenzoic,  407. 

olefin,  375. 

propionic,  292,  362. 


648 


INDEX 


Acids,  oxy  tricarboxylic,  297. 
paraffin  dicarboxylic,  285. 

monocarboxylic,  277,  285. 

pentacarboxylie,  289. 

tetracarboxylic,  289. 

tricarboxylic,  289. 
pentoxydicarboxylic,  297. 
pentoxymonocarboxylic,  294. 
phenanthrene  carboxylic,  445. 
phenol  carboxylic,  403. 

sulfonic,  390. 
phosphorus,  119. 
phenyl  acetylene  carboxylic,  403. 

acrylic,  402. 

alcohol,  408. 

alcohol  ketone,  409. 

amido,  423,  424. 

diketone,  409. 

fatty,  401. 

hydracrylic,  408. 

ketone  dicarboxylic,  409. 

lactic,  408. 

olefln  carboxylic,  402. 

paraffin  alcohol,  407,  408. 

propionic,  401. 
phenylene  ketone  dicarboxylic,  409. 

oxydicarboxylic,  408. 
phthalic,  401. 
phthalid,  408. 
picolinic,  461. 

polycarboxylic,  aromatic,  401. 
pure,  277. 

carboxylic,  361. 
pyridin  carboxylic,  461,  480. 

dicarboxylic,  461. 

monocarboxylic,  461. 
quinolin  carboxylic,  480,  481. 
resorcylic,  405. 
saccharic,  294,  297. 
sulflnic,  313,  322,  415. 
sulfobenzoic,  403. 
sulfonic,  321,  322, 
sulfonic,  aromatic,  415. 

diazoamido,  428. 
sulfurous,  97. 
tannic,  406. 
tartaric,  295. 
taurocholic,  523. 
tetracarboxylic,  289. 
tetroxydicarboxylic,  297. 
tetroxymonocarboxylic,  294. 
thiocarbamic,  350. 
thiosulfuric,  322. 
toluene  sulfonic,  415. 
toluic,  386. 
tricarboxylic,  289. 
triketone  monocarboxylic,  298. 
trioxy monocarboxylic,  293. 
un saturated  aromatic,  402. 
valerianic,  282. 
volatile  fatty,  277. 
Acidulous  elements,  57,  79. 
Acidyl  anhydrids,  256,  310,  351. 

chlorids,  256,  310,  311,  312,  341,  346,  357. 
cyanids,  341. 
haloids,  257,  311. 
Acidyls,  278,  302. 
Aconin,  491. 
Aconite  alkaloids,  491. 
Aconitin,  472,  491. 
Acridin,  462,  463. 
Acrolem,  253,  372,  373,  374,  462,  463. 


Action  on  the  economy  (see  also  Toxicol- 
ogy). 

of  acetic  acid,  281. 

ammonium  compounds,  187. 

antimony,  139. 

arsenicals,  128. 

barium,  193. 

biliary  salts,  531. 

bismuth,  164. 

carbolic  acid,  390. 

carbon  dioxid,  306,  308. 
disulfld,  324. 
monoxid,  302,  549. 

chloral,  259. 

chloroform,  235. 

chromium,  148. 

copper,  207. 

cyanics,  338. 

ether,  301. 

lead,  160. 

mercury,  214. 

oxalic  acid,  287. 

phenol,  390. 

phosphates,  121. 

potassium,  182. 

silver,  184. 

sodium,  182. 

zinc,  197. 

Acyclic  compounds,  227,  229. 
Addition,  224. 
Adenin,  356,  357,  359. 
Adipocere,  502. 
Adjacent  positions,  382. 
Adonite,  255. 

^sculetin,  410,  412,  463,  464. 
^Esculin,  410. 
JSthiops  mineralis,  210. 
After-damp,  231. 
Agate,  144. 
Air,  63,  102. 

alveolar,  562. 

ammoniacal  compounds  in,  103. 

carbon  dioxid  in,  103,  304. 

humidity  of,  103. 

solid  particles  in,  104. 
Alabaster,  188,  190. 
Alanin,  364. 
Alanins,  362,  364. 
Albumens,  497,  498. 

coagulated,  498. 

derived,  497. 

general  reactions  of,  502. 

native,  497. 

Albuminates,  497,  504. 
Albumin,  coagulation  of,  331. 
Albumins,  497,  503. 

coagulated,  498. 

decompositions  of,  499. 

vegetable,  509. 
Albuminoids,  497,  498,  507. 
Albuminous  compounds,  497. 

substances,  497,  498. 
Albuminuria,  593. 
Albumoses.  498,  500,  518,  519,  601. 

anti,  518. 

deutero,  518,  519. 

hemi,  518. 

hetero,  518,  519. 

primary,  518,  519. 

proto,  518,  519. 

secondary,  518,  519. 
Albumosuria,  602. 


INDEX 


649 


Alcohol  (see  also  Alcohols),  242. 

absolute,  243,  245. 

acids,  277,  289. 

allyl,  371,  372,  373. 

amido  ethyl,  366. 

amylic,  242,  250. 

benzole,  397. 

benzylic,  388,  397,  399. 

bromallyl,  372. 

butylic,  242. 

cetyl,  251,  284. 

cinnaraic,  398. 

coniferyl,  411. 

crotonyl,  373. 

esters,  311. 

ethylic,  238,  242,  279,  346. 

fluorene,  444. 

isobutyl,  249,  282. 

methylic,  241,  279. 

nitroethyl,  360. 

oxybenzyl,  398. 

propargyl,  371,  372. 

propenyl,  253. 

propylic,  242,  248,  372. 

vinic,  242. 

vinyl,  371. 

wood,  241. 

Alcoholates,  244,  278,  299. 
Alcoholic  beverages,  245. 
Alcohols  (see  also  Alcohol),  239,  256,  278, 
289,  328,  346,  371,  448. 

acetylene,  372. 

allyl,  256. 

amido,  360. 

amylic,  241.  249,  282. 

aromatic,  397. 

butyl,  249. 

camphan,  435. 

diatomic,  239,  240,  251,  329. 

dihydric,  239,  240,  251. 

diolefln,  372. 

diprimary,  285. 

heptatomic,  255. 

hexatomic,  255,  265,  294. 

hexahydric,  255,  265,  294. 

hydroaromatic,  434. 

iso,  242. 

menthan,  435. 

menthene,  435. 

methods  of  formation,  241. 

monoatomic,  218,  239,  240,  329. 

monohydric,  218,  239,  240,  329. 

naphthyl,  444. 

nitrogen  derivatives  of,  360. 

nomenclature  of,  240. 

nonatomic,  255. 

octatomic,  255. 

of  condensed  hydrocarbons,  442. 

olefin,  371. 

oxyphenyl,  398. 

pentatomic,  254. 

pentahydric,  254. 

polyatomic,  240,  254. 

polyhydric,  240,  254. 

primary,  238,  239,  240. 

ring.  434. 

secondary,  238,  239,  240,  241. 

secondary  ring,  434,  43(i. 

terpan,  434,  436. 

tertiary,  238,  239,  240. 

tetratomic,  254. 

triatomic,  252. 


Alcohols,  trihydric,  252. 
Aldehyde   (See  also  Aldehydes),  243,  244, 
245,  257,  292,  301,  360. 

acetic,  238,  257. 

acids,  277,  285,  291,  297,  429. 

acrylic,  372. 

alcohols,  255,  262. 

ammonias,  257,  258,  331,  360,  459,  460. 

anisic,  399. 

benzoic,  337. 

betain,  332. 

butyric,  261,  473. 

cinnamic,  399. 

crotonic,  258,  372. 

cuminic,  392,  396,  399. 

formic,  257,  322,  363. 

furfur,  454. 

glycerol,  256,  264. 

glycolyl,  239,  256,  264. 

green,  451. 

hydrazones,  360. 

isovaleric,  364. 

ketones,  262. 

ketone  acids,  298. 

methylprotocatechuic,  399,  411. 

orthoamidobenzoic,  467. 

oxypyroracemic,  263. 

propargyl,  373. 

propionic,  261. 

propylic,  372. 

salicylic,  398,  399,  404,  414,  437,  464. 

thioformic,  322. 

Aldehydes  (see  also  Aldehyde),  226,  238, 
239,  255,  256,  278,  290,  311,  341, 
360,  371,  429,  467. 

aromatic,  398. 

naphthyl,  444. 

nitrogen  derivatives  of,  360. 

olefin,  372. 
Aldehydin,  460. 
Aldehydrazones,  430. 
Aldoalcohols,  429. 
Aldohexoses,  255,  264,  294,  321. 
Aldol,  257,  263,  372. 
Aldopentoses,  255,  264,  294. 
Aldoses,  263,  264,  429. 
Aldoxims,  256,  341,  360. 
Ales,  245,  246. 
Aleurone  corpuscles,  509. 
Algaroth,  powder  of,  137. 
Aliphatic  compounds,  227. 
Alizarin,  445. 

dyes,  440. 
Alkali,  168. 

albumens,  498,  504. 

blue,  451. 

carbonated,  168. 

caustic,  168. 

metals,  168. 

volatile,  104,  168. 
Alkaline  earths,  metals  of,  188. 
Alkaline  reaction,  41. 
Alkaloids,  469. 

aconite,  491. 

atropic,  472. 

berberis,  472,  484. 

cinchona,  472,  478,  480. 

classification  of,  320. 

corydalis,  472,  484. 

general  reactions  of,  472. 

hydrastis,  472,  484 

isoquinolin,  472,  484. 


650 


INDEX 


Alkaloids,  opium,  472,  484,  488. 
pyridin,  472. 
pyrrole,  472. 
quinolin,  472,  478. 
separation  of,  470. 
strychnos,  472,  481. 
Alkanes,  230. 

Alkaptonuria,  405,  406,  606. 
Alkarsin,  368. 
Alkyls,  230,  239. 
Alkyl  benzenes,  385. 
haloids,  327. 
pyridinium  iodids,  460. 
pyridins,  460. 
ureas,  337,  343,  350,  351. 
Allantoi'n,  351,  352,  353. 
Allene,  371. 

Allometa  compounds,  384. 
Allortho  compounds,  384,  442. 
Allotropy,  12. 

Alloxan,  298,  348,  352,  353,  354,  355. 
Alloxantin,  352,  353,  354,  355. 
Alloxuric  bases,  356. 
Allyl  alcohol,  371. 
amin,  377. 
anilin,  467. 
cyanids,  373. 
guaiacol,  395. 
haloids,  371,  373. 
iodid,  371,  372,  373,  376,  377. 
isothiocyanate,  343,  377,  413. 
oxid,  376. 
phenol,  395. 
pyrocatechol,  395. 
sulfid,  377. 

tetraoxybenzene,  395. 
tribromid,  253. 
Allylene,  371. 
Alphenols,  398. 
Alumina,  199. 
Aluminates,  198,  199,  200. 
Aluminium,  29,  36,  58,  198. 
acetylacetate,  198. 
bronze,  199. 
chlorid,  200. 
hydroxid,  199. 
oxid,  199. 
silicate,  144,  201. 
sulfate,  200. 
Alums,  148,  200. 
Alveolar  air,  562. 
Amalgams,  209. 
Amanitin,  331,  332. 
Amber,  288,  438. 
Ambergris,  538. 
Amic  acids,  346,  347. 
Amid,  benzoyl,  423. 
Amidin  bases,  cyclic,  *333. 
Amidins,  334,  335. 
Amido  acetaldehyde,  360,  462. 
acetones,  361. 
acids,  346,  361. 
aromatic,  416. 
alcohols,  360. 
aldehydes,  360. 
azo  compounds,  428. 
benzenes,  419,  422,  445 
diphenyls,  447. 
ketones,  361. 
malonyl  urea,  352,  359. 
naphthalenes,  445. 
paraffins,  325,  326. 


Amido  phenols,  393,  419,  423. 
phenyl,  423. 
acids,  423. 
purin,  357,  359. 

thioacids,  366. 

toluyls,  447. 

triphenyl  carbinols,  449 

triphenyl  methanes,  449. 

xylenes,  420. 
Amido-benzol,  419. 
Amidoxims,  334,  335,  426. 
Amids,  335,  345,  351. 

amidosuccinic,  366. 

aromatic,  416,  423. 

mixed,  345. 

primary,  328,  361. 

secondary,  328. 

tertiary,  328. 
Amin  bases,  326. 
Amins,  326,  345,  350. 

aromatic,  416. 

primary,  241,  327,  328,    340,  343,  344, 
361. 

secondary,  328. 

tertiary,  328. 

unsaturated,  330. 
Ammelid,  349. 
Ammonia,  104. 

caustic,  185. 

Ammonio-magnesian  phosphate,  194,  575. 
Ammonium,  104,  185. 

acetate,  187. 

amalgam,  185. 

bromid,  186. 

butyrate,  282. 

carbamate,  187,  346,  577. 

carbonates,  187,  577. 

chlorid,  105,  186. 

compounds,  185. 

cyanate,  216,  355. 

derivatives,  326. 

hydroxid,  105,  185. 

iodid,  186. 

isothiocyanate,  349,  350. 

nitrate,  186. 

sesquicarbonate,  187. 

sulfamate,  185. 

sulfates,  186. 

sulfhydrate,  186. 

sulflds,  186. 

theory,  185. 

thiosulfate,  186. 

urate,  354,  355. 
Ampere,  28. 
Amphi  compounds,  442. 
Amphicreatinin,  337. 
Amphopeptone,  519. 
Amphoteric  elements,  57,  146. 
Amygdalin,  337,  410. 
Amyl  acetate,  315. 

caprate,  283. 

chlorid,  250. 

cyanid,  283. 

nitrate,  314. 

nitrite,  314. 

oxid,  314. 
Amylamin,  365. 
Amylene,  251,  369. 

hydrate,  251. 
Amyloid,  498,  505. 
Amylopsin,  534. 
Amylum,  274. 


INDEX 


651 


Ana  compounds,  442. 
Analysis,  31,  69. 

organic,  219. 

Analytical  characters  (see  also  Test;  Reac- 
tion; Reagent). 

acetates,  280. 

alcohol,  245. 

aluminium,  201. 

ammonium,  187. 

antimony,  132,  134,  139. 

arsenic,  135. 

arsenous,  135. 

atropin,  476. 

barium,  192. 

bismuth,  163. 

bromids,  87. 

brucin,  483. 

cadmium,  198. 

calcium,  191. 

carbolic  acid,  390. 

chlorids,  85. 

chloroform,  285. 

chromates,  148. 

chromic,  148. 

chromous,  148. 

cobalt,  2.03. 

cocain,  478. 

codein,  486. 

coniiin,  473. 

cupric,  207. 

cuprous,  207. 

cyanids,  338. 

ferric,  156. 

ferrous,  156. 

gold,  146. 

hydrogen,  62. 

hydrogen  peroxid,  78. 

hydrogen  sulfid,  94. 

iodids,  90. 

lead,  160. 

lithium,  169. 

magnesium,  195. 

manganic,  149. 

manganous,  149. 

mercuric,  214. 

mercurous,  214. 

morphin,  485. 

narcein,  487. 

narcotin,  487. 

nickel,  203. 

nicotin,  474. 

nitrates,  111. 

oxalates,  286,  287. 

oxygen,  66. 

ozone,  67. 

phenol,  390. 

phosphates,  121. 

phosphorus,  115. 

potassium,  182. 

quinin,  479. 

silver,  184. 

sodium,  174. 

strontium,  191. 

strychnin,  482. 

sulfates,  99. 

sulfids,  94. 

sulfites,  97. 

sulfur  dioxid,  96. 

thebaiin,  487. 

tin,  166. 

zinc,  197. 
Anethol,  395,  399. 


Anglesite,  156. 

Anhydrid,  acetic,  310,  320,  351. 

antimonic,  137. 

antimonous,  137. 

arsenic,  125. 

arsenous,  125. 

benzoic,  414. 

boric,  140. 

carbonic,  304. 

chromic,  147. 

citraconic,  376. 

hypochlorous,  86. 

itaconic,  376. 

manganic,  149. 

manganous,  149. 

maleic,  295,  375. 

methylguanidin-acetic,  336. 

molybdic,  145. 

nitric,  109. 

nitrous,  107. 

phosphoric,  119. 

phosphorous,  119. 

phthalic,  394,  395,  396,  407,  414. 

plumbic,  158. 

silicic,  144. 

succinic,  288. 

sulfuric,  96. 

sult'urous,  95. 

tungstic,  145. 

titanic,  164. 

tartaric,  296. 
Anhydrids,  53,  65. 

acidyl,  310,  351. 

aromatic,  414. 

haloid,  311. 

organic,  241,  295,  302. 
Anhydrogeraniol,  371. 
Anilido  acids,  423. 
Anilids,  421,  425. 

of  dicarboxylic  acids,  423. 
Anilin,  417,  419,  422,  425,  426,  427,  428,  429, 
454,  464,  467,  472. 

chlorid,  449. 

colors,  420. 

derivatives  of,  421. 

dyes,  422,  426,  428,  449,  450,  451. 

hydrochlorid,  426. 

oil,  451. 

red,  451. 
Anils,  397. 
Animal  gum,  543. 
Anions,  29. 
Anisidins,  418,  423. 
Anilins,  428,  459. 
Anisol,  409. 
Anisols,  nitro,  418. 
Annidalin,  393. 
Anode,  27. 
Anol,  395. 
Anthracene,  438,  440,  442,  444,  467. 

haloids,  442. 

oil,  385. 

nitrogen  derivatives  of,  445. 
Anthracite,  141. 
Anthranol,  444. 
Anthraphenols,  443. 
Anthrapyridins,  462,  463. 
Anthraquinolin,  453. 
Anthraquinolins,  462. 
Anthraquinone,  440,  441,  444. 
Anthrols,  444. 
Antialbumoses,  518,  519. 


INDEX 


Antiarin,  411. 
Autifebrin,  421,  457. 
Antimony,  29,  36,  57,  101,  136. 

acids  of,  138. 

antimonate,  138. 

black,  138. 

butter  of,  136. 

chlorids  of,  137. 

cinnabar,  139. 

crocus  of,  138. 

glass  of,  138. 

intermediate  oxid,  138. 

liver  of,  138. 

oxids  of,  137. 

oxychlorid,  137. 

oxysulfids,  138,  139. 

pentachlorid,  137. 

pentasulfid,  139. 

pentoxid,  137. 

sulflds  of,  138. 

tartarated,  180. 

trichlorid,  136. 

trioxid,  137. 

trisulfld,  138. 

vermilion,  139. 
Antimonyl,  136. 

salts,  136. 
Antipeptone,  519. 
Antipyrin,  429,  457. 

salicylate,  458. 
Antiseptics,  501. 
Antitoxins,  493,  495. 
Antitussin,  446. 
Apiin,  411. 
Apiol,  395. 
Apo-alkajoids,  471. 
Apomorphin,  484,  486,  487,  490. 
Apoquinin,  480. 
Aqua  ammoniae,  104. 

chlori,  82. 

fortis,  110. 

regia,  84,  111. 

saphirina,  206. 
Arabin,  275. 

Arabinose,  265,  275,  294. 
Arabite,  240. 
Arbutin,  411. 
Archil,  394. 
Arecai'din,  478. 
Arecain,  478. 
Arecolin,  470,  472,  478. 
Arginin,  340,  499. 
Argol,  179. 
Argon,  36,  102. 
Aricin,  478. 
Aristol,  392. 
Aromatic  amidoacids,  423. 

acid  amids,  423. 

compounds,  227. 
classification  of,  384. 

substances,  380. 
Arsenamin,  123. 
Arsenates,  127,  128. 
Arsenia,  123. 
Arsenic,  29,  36,  57,  101,  122. 

disulfid,  127. 

oxids,  124. 

pentoxid,  125. 

pentasulfid,  127. 

sulflds  of,  127,  129. 

tribromid,  124. 

trichlorid,  124. 


Arsenic,  trifluorid,  124. 

triiodid,  124. 

trioxid,  125,  128. 

trisulfid,  127. 

white,  125. 

Arsenical  greens,  129. 
Arsenites,  125,  126. 
Arsins,  368. 
Arterin,  546. 
Artesian  wells,  71. 
Artiads,  39. 
Asbestos,  193. 
Asellin,  319. 
Aseptol,  416. 
Asparagins,  366. 
Asphalt,  438. 
Atom,  33,  34,  35,  40. 
Atomicity,  39,  42,  43,  290. 
Atomic  heat,  37. 

theory,  32. 

weight,  35,  36. 
Atropic  alkaloids,  472. 
Atropin,  453,  472,  475 
Auric  chlorid,  146. 
Aurin,  390,  395. 
Auripigmentum,  127. 
Auroamidoimid,  343. 
Azo  benzene,  427,  428,  429,  447. 

compounds,  416,  426,  427. 

dyes,  427,  447. 

imid,  105. 
Azoles,  456. 

Azonaphthalene  compounds,  446. 
Azonaphthol  compounds,  443. 
Azoxy  compounds,  428. 
Azoparaffins,  337. 
Azoxybenzene,  428. 
Azurite,  206. 

Baking  powders,  180. 

Balsams,  438. 

Barium,  29,  36,  58,  188,  192. 

carbonate,  192. 

chlorid,  192. 

cobaltite,  203. 

dioxid,  192. 

hydroxid,  192. 

monoxid,  192. 

nitrate,  192. 

oxids,  192. 

peroxid,  65,  77,  192. 

pyromucate,  454. 

sulfate,  192. 
Bases,  42,  46,  66. 
Basic  oxids,  66. 

salts,  43,  52. 
Basicity,  42,  223,  290. 
Bassorin,  275. 

Basylous  elements,  57,  58,  168. 
Battery,  27. 
Beauxite,  198,  199,  200. 
Beers,  245,  246. 
Beeswax,  251,  315. 
Belladonin,  475. 
Benzamid,  401,  423,  425,  426. 
Benzene,  279,  370,  378,  380,  385,  401,  425, 
429. 

amido,  419. 

amido  compounds  of,  416,  417,  419. 

azomethane,  427. 

haloid  derivatives  of,  387. 

homologucs  of,  385. 


INDEX 


653 


Benzene,  hydroxylamin  compounds  of,  416, 
417,  419. 

imido  compounds  of,  416. 

nitro,  419. 

nitro  compounds  of,  410,  417. 

nitrogen  derivatives  of,  416. 

nitroso,  419. 

nitrciso  compounds  of,  416,  417. 

ring,  438. 

substitution  products  of,  381. 

sulfur  derivatives  of,  415. 
Benzenyl,  401. 

amidin,  401. 

amidoxim,  426. 
Benzhydrol,  448,  449. 
Benzidin,  429,  447. 
Beuzil,  449. 
Benzine,  232,  385. 
Benzodiazins,  462. 
Benzofurfurane,  463. 
Benzoin,  389,  449. 
Benzol,  385. 
Benzolene,  232. 
Benzonitril,  422. 
Benzophenol,  389. 
Benzophenones,  448. 
Benzopyridin,  463. 
Benzopyridin  bases,  467. 
Benzopyrones,  464. 
Benzopyrrole,  463,  464. 
Benzoquinone,  396,  397. 
Benzosol,  393. 
Benzoyl,  388,  401,  424. 

amid,  423. 

chlorid,  255,  265,  330,  367,  399,  400,  414, 
423,  425,  494,  499. 

cyanid,  399,  414. 

diazoimid,  105. 

ecgonin,  477. 

glycocoll,  425. 

hydrid,  398. 

morphin,  484. 

salicin,  414. 

sulfonic  imid,  416. 
Benzyl,  388. 

acetate,  414. 

benzene,  447. 

chlorid,  388,  447. 

hydrate,  497. 

sulfld,  447. 

Berberis  alkaloids,  472. 
Beryl,  202. 

Beryllium,  29,  36,  58.  198,  202. 
Beta-butandiol,  251. 
Betaifn  aldehyde,  332. 
Betams,  332,  493. 
Beta-naphthol,  384. 
Bezoar  stones,  538. 
Bidiphenylene  ethane,  439. 
Bieberich  scarlet,  443. 
Bile,  525-533. 

acids,  526,  527,  536. 

bilirubin  in,  527. 

biliverdin  in,  529. 

cholesterol  in,  529. 

coloring  matters  of,  527,  531,  544,  605. 

composition  of,  526. 

lecithins  in,  526. 

quantity  of,  525. 

salts,  526,  530,  544,  605. 

sodium  glycochojate  in,  527. 

sodium  taurocholate  in,  527. 


Bile,  urea  in,  526. 
Biliary  calculi,  532. 
Bilicyanin,  528. 
Bilifuscin,  529. 
Bilihumin,  529. 
Bilineurin,  330. 
Biliprasin,  529. 
Bilirubin,  527,  531. 
Biliverdin,  528,  529. 
Binary  compounds,  32,  50. 
Bioses,  264. 
Bi-salts,  43,  52. 
Bismark  brown,  110,  422. 
Bismuth,  29,  36,  57,  101,  162. 

hydrates,  162. 

hydroxid,  162. 

nitrate,  162,  163. 

oxids,  162. 

pentoxid,  163. 

subcarbonate,  162,  163. 

subnitrate,  163. 

sulfate,  162. 

sulfid,  164. 

trichlorid,  163. 

trioxid,  162. 
Bismuthates,  162. 
Bismuthyl,  162. 

carbonate,  163. 

chlorid,  163. 

hydroxid,  163. 

nitrate,  163. 

Bitter  almond  oil  green,  450. 
Bitter  almonds,  oil  of,  398. 
Biuret,  349,  351. 
Black  flux,  178. 

lead,  141. 

wash,  209. 

Bleaching  powder,  189. 
Blood,  538-560. 

alkalinity  of,  553,  555. 

arterin  in,  546. 

bile  pigments  in,  544. 

bile  salts  in,  544. 

carbohydrates  in,  542. 

carbon  dioxid  in,  564. 

changes  in  composition  of,  557. 

changes  in  the  liver,  557. 

chemical  examination  of,  555. 

cholesterol  in,  542,  545,  552. 

clot,  539. 

coagulation  of,  539,  553. 

coloring  substances,  545. 

corpuscles,  538,  545. 
mineral  salts  of,  552. 

creatin  in,  544. 

enzymes  in,  543. 

extractives  of  plasma,  544. 

fats  in,  542,  545. 

fibrin  of,  439,  541. 

fibrinogen  in,  540. 

gases  of,  562. 

glucose  in,  542,  543,  544,  559. 

glycogen  in,  542,  552,  558. 

glycolysis  in,  543. 

haemoglobin  in,  545,  556, 

hippurates  in,  544. 

jecorin  in,  541,  543,  544. 

lakeing  of,  545. 

lecithins  in,  542,  545,  552. 

leucin  in,  544. 

leucocytes,  545,  552. 

lipolysis  in,  543. 


654 


INDEX 


Blood,  oxygen  in,  562. 

oxy haemoglobin  of,  545. 

paralactates  in,  544. 

phlebin  in,  546. 

physical  characters  of,  553. 

plaques,  545,  553. 

plasma,  538,  540, 

platelets,  545. 

prothrombin  in,  541,  552,  554. 

red  corpuscles  of,  545. 
stroma  of,  545,  551. 

serum,  539,  540,  542. 

serum-albumin  in,  542. 

serum-globulin  in,  541. 

serum,  mineral  salts  in,  544. 

soaps  in,  542. 

specific  gravity  of,  553,  555. 

thrombin  in,  540,  541,  554. 

tyrosin  in,  544. 

urates  in,  544. 

urea  in,  544. 

white  corpuscles  of,  545,  552 

xanthin  bases  in,  544. 
Blue  ash,  206. 

mass,  209. 

stone,  205. 
Bog  ore,  150,  155. 
Boiling,  18. 

Boiling  point,  18,  68,  222. 
Bone  ash,  190. 

black,  142. 

oil,  459,  467. 

phosphate,  190. 
Borax,  140,  172. 
Bordeaux  dyes,  443. 
Borneo  camphor,  433. 
Borneol,  435,  437. 
Boroglycerid,  140. 
Boron,  29,  36,  57,  140. 

trioxid,  140. 

Bottcher's  crystals,  334. 
Braunite,  148. 
Brom-acetophenone,  465. 
Bromal,  244,  260. 

hydrate,  260. 
Bromids,  87. 
Bromin,  29,  36,  57,  79,  86. 

oxyacids  of,  87. 
Bromanilins,  421. 
Bromindene,  441. 
Bromobenzene,  386. 
Bromoform,  236,  260,  262. 
Bromol,  393. 
Bromophenols,  393. 
Brucin,  472,  481,  483. 
Butalanin,  364. 
Butane,  229. 
Butanes,  285. 
Butene,  229. 
Butone,  229. 
Butter,  282,  283,  622. 

fat,  622. 
Butyl  benzenes,  386. 

carbinols,  241. 
Butylene  hydrate,  249. 
Butyrolactam,  363,  456. 
Butyrolactone,  363. 
Butyrylmorphin,  484. 
Bz.  bromindene,  441. 

Cacodyl.  367,  368. 
cyanid,  368. 


Cacodyl,  oxid,  368. 

Cadaverin,  333. 

Cadet,  liquid  of,  368. 

Cadmium,  29,  36,  58,  193,  198. 

Caesium,  168. 

Caff  em,  354,  356,  368,  470. 

Calamine,  195,  197. 

Calc  spar,  190. 

Calcium,  29,  36,  58,  188. 

acetylid,  370. 

carbid,  189,  243,  370. 

chlorid,  189. 

group,  188. 

hydroxid,  189. 

hypochlorite,  82,  189. 

oxalate,  191,  594. 

oxid,  188. 

phosphates,  112,  190. 

pimelate,  436. 

plumbite,  158. 

sulfate,  190. 

superphosphate,  112. 

urates,  355. 
Calculi,  biliary,  532. 

fusible,  575. 

intestinal,  538. 

mulberry,  191,  594. 

phosphatic,  575. 

renal,  569. 

salivary,  515. 

urinary,  355,  356,  569,  575,  618-621. 
Calomel,  210. 
Calorie,  19. 
Camphans,  432,  433. 
Camphene,  432,  433,  436,  437. 
Camphol,  435. 
Camphor,  289,  436,  437. 

artificial,  433. 

Borneo,  435. 

Japan,  436. 

laurel,  436. 

monobromo,  437. 
Camphors,  431. 
Camphoryl  morphin,  484. 
Campobello  yellow,  443. 
Cane  sugar,  270,  559. 
Caramel,  271. 
Carat,  146. 
Carbamid,  348,  576. 
Carbamins,  340. 
Carbanil,  orthoxy,  421. 
Carbazole,  439,  446,  462,  463,  467. 
Carbids,  370. 
Carbiinid,  343. 
Carbinol,  240,  241. 

butyl,  250. 

diethyl,  250. 

ethyl,  248. 

ethyldimethyl,  251. 

isobutyl,  250. 

isopropyl,  249. 

methyl,  242. 

methylisopropyl,  251. 

methylpropyl,  250. 

phenyldimethyl,  398. 

phenylmethyl,  398. 

propyl,  249. 

trimethyl,  249. 

Carbinols,  phenyl,  448,  450,  451. 
Carbocyclic  compounds,  228,  378,  379. 
T!arbodiimids,  420. 
Carbohydrates,  263,  297,  535,  542. 


INDEX 


655 


Carbolates,  390. 
Carbolic  oil,  385. 
Carbon,  29,  36,  57,  141. 

amorphous,  141. 

compounds  of,  216,  226,  227. 

dichlorid,  233. 

dioxid,  103,  285,  304,  564. 
haemoglobin,  550. 

disulfid,  324,  343,  350. 

metallic,  142. 

monoxid,  278,  285,  302. 
haemoglobin,  549. 

oxids  of,  302. 

oxysulfid,  324,  344. 

trichlorid,  236,  237,  316. 

tetrabromid,  236. 

tetrachlorid,  233,  236. 
Carbonic  oxid,  302. 
Carbonous  oxid,  302. 
Carbonyl,  256. 

chlorid,  302,  349,  351,  353. 

diurea,  353. 
Carborundum,  144. 
Carbostyril,  468. 
Carbotriamin,  335. 
Carboxyl,  239,  278. 
Carbylamins,  328,  340. 
Carbyloxim,  343. 
Carmine-red,  411. 
Carnallite,  175. 
Carnelian,  144. 
Carnin,  356,  357. 
Carvacrol,  392,  435,  436,  437. 
Carvol,  392,  436. 
Carvone,  435,  436. 
Carvoxims,  436. 
Casein,  279,  497,  623,  624. 
Caseinogen,  623. 
Caseins,  vegetables,  509. 
Caseoses,  518. 
Cassel  yellow,  159. 
Cassiterite,  165. 
Catechin,  393. 
Catechol,  590. 
Cathions,  29. 
Celestine,  191. 
Cellulin,  276. 
Cellulose,  273,  276,  535. 

nitro,  277. 
Celluloid,  277. 
Cerebrin,  269,  553. 
Cerebrose,  269. 
Cerium,  29,  36,  58. 
Cerusite,  160. 
Ceryl  cerotate,  315. 
Cesium,  29,  36,  58,  183. 
Cetaceum,  315. 
Cetin,  315. 
Cetyl  cyanid,  284. 

hydroxid,  251. 

palmitate,  315. 
Chains,  227. 
Chalcosine,  205. 
Chalk,  188,  190. 

precipitated,  191. 
Chalky  deposits,  354. 
Characterizing  groups,  225. 
Charcoal,  142,  279. 

animal,  142. 
Charcot's  crystals,  334. 
Chavicol,  395. 
Chslidonin,  458. 


Chemical  activity,  45. 

China  wax,  251,  315. 

Chinovase,  265. 

Chitin,  508. 

Chloral,  244,  257,  268,  301. 

alcoholate,  259. 

ammonia,  348. 

butyric,  261. 

hydrate,  259,  298,  348. 
Chloralamid,  347. 
Chloralid,  259. 
Chloralimid,  348. 
Chloralum,  200. 
Chloranilins,  392,  421. 
Chloraurates,  146. 
Chlorazone,  173. 
Chlorhydrargyrates,  209,  212. 
Chlorids,  70,  84. 
Chlorin,  29,  36,  57,  61,  79,  80. 

monoxid,  86. 

oxids  of,  86. 

peroxid,  86. 

tetroxid,  86. 

water,  82. 
Chlorination,  65. 
Chlorindones,  441. 
Chlorobenzenes,  382. 
Chlorocarbon,  236. 
Chlorodibromobenzenes,  383. 
Chloroform,    234,   259,   262,   278,  328,   337, 

341,  347,  348,  370,  422,  447. 
Chloromercurates,  209,  212. 
Chloromethyl,  233. 
Chlorophenols,  392. 
Chlorophyll,  511. 
Cholesterol,  503,  529,  532,  542. 

esters  of,  542. 
Choletelin,  528. 
Cholin,  319,  330,  331,  332. 
Chondroalbumens,  603. 
Chondroitin,  603. 
Chondromucoid,  505. 
Chondroproteids,  505,  603. 
Chondrosin,  603. 
Chrome  ironstone,  147. 

yellow,  159. 
Chromic  oxid,  147. 
Chromium,  29,  36,  57,  147. 

chlorids,  148. 

green,  147. 

oxychlorid,  148. 

salts  of,  147. 

sesqueoxid,  147. 

sulfates,  148. 
Chrysanthemin,  478. 
Chrysarobin,  445. 
Chrysazol,  444. 
Chrysene,  438,  439,  441. 
Chrysin,  464. 
Chyluria,  532,  567. 
Chymosin,  520,  543,  623. 
Chymosinogen,  520. 
Cider,  245,  248. 
Cinchona  alkaloids,  472. 

red,  478. 

Cinchonicin,  480. 
Cinchonidin,  461,  478,  480. 
Cinchonin,  461,  470,  472,  478,  480,  481. 
Cinene,  432. 
Cineol,  432,  435. 
Cinnabar,  208,  210. 
Cinnamene,  440. 


656 


INDEX 


Cinnolin,  462. 

Cis-terpin,  435. 

Citronellal,  373. 

Classification  of  aromatic  compounds,  384. 

of  carbon  compounds,  227. 

of  elements,  56. 
Clay  ironstone,  150,  155. 
Clays,  198,  201. 

Closed-chain  compounds,  227,  378. 
Clot,  539. 
Clupein,  500. 

Coagulated  albumens,  498,  505. 
Coagulation,  498. 

of  blood,  539. 
Coal,  141. 

tar,  385. 

Cobalt,  29,  36,  58,  203. 
Cobalticyanids,  345. 
Cocam,  453,  472,  477. 

homologues,  477. 
Codein,  472,  484,  486,  488,  489,  490. 

methyl  iodid,  489. 
Coarulignone,  447. 
Coke,  142. 
Colchicin,  492. 
Colcothar,  151. 
Collagen,  498,  508,  519. 
Collidin,  474,  493. 
Collidins,  460. 
Collodion,  277. 
Colloids,  20. 
Colophany,  433. 
Colorometric  methods,  556. 
Columbium,  36,  144. 
Combustion,  65. 

supporters  of,  65. 
Composition,  1,  53. 
Compound  ammonias,  326. 

radicals,  52. 

ureas,  350. 
Compounds,  31. 

acyclic,  227,  229. 

aliphatic,  227,  229. 

aromatic,  227,  380. 

binary,  50. 

carbocyclic,  228,  379. 

closed-chain,  227,  378. 

cyclic,  227,  378. 

fatty,  227,  229. 

heterocyclic,  228,  452. 

open-chain,  227,  229. 

saturated,  229. 

with  condensed  nuclei,  438. 
Conchiolin,  508. 

Condensed    heterocyclic    compounds,    430, 
441,  453,  462. 

hydrocarbons,  439. 

haloid  derivatives  of,  441. 

nuclei,  compounds  with,  438. 
Conductivity,  electrical,  44. 

molecular,  44,  223. 
Conductors,  27. 
Condy's  disinfectants,  173. 
Conglutin,  509. 
Congo  red,  447. 
Conhydrin,  472. 
Coniferin,  399,  411. 
Coniin,  364,  460,  461,  470,  472. 
Consecutive  positions,  382. 
Constitution,  53,  218,  224. 
Contact  action,  300. 
Convolvulin,  411. 


Conyrin,  460. 

Copper,  29,  36,  58,  204. 

acetates,  206. 

acetylid,  368,  370. 

ammonio-sulfate,  206. 

carbonates,  206. 

chlorids,  205. 

glance,  205. 

hydroxids,  205. 

oxids,  204. 

phenyl acetylid,  448. 

sulfld's,  205. 
Copperas,  153. 
Coprolites,  190. 
Corallin,  390,  395. 
Cordials,  248. 
Coridins,  460. 
Corpuscles,  blood,  538. 
Corrosive  sublimate,  210. 
Corrosives,  85. 
Corundum,  199. 
Corydalis  alkaloids,  472. 
Cosmoline,  232. 
Cotarnin,  487,  489. 
Cotton,  gun,  277. 
Coulomb,  28. 

Coumarin,  404,  410,  463,  464. 
Coumarins,  463. 
Coumaroue,  463. 
Cream,  622. 
Creamometer,  621. 
Creasol,  391. 
Creasote,  279,  391. 
Creasote  oil,  385. 

Creatin,  335,  336,  348,  364,  544,  578,  585. 
Creatinin,  335,  336,  585. 
Creolin,  391. 
Cresols,  391. 

nitro,  418. 
Cresylols,  391. 
Cristallin,  419. 
Crith,  61. 
Croeetin,  411. 
Crocin,  411. 
Croton  aldehyde,  372. 

chloral  hydrate,  261. 
Cruso-creatinin,  336. 
Cryolite,  174,  198,  199,  200. 
Crystal  violet,  451. 
Crystallization,  7. 

water  of,  12,  48. 
Crystalloids,  20. 
Crystals,  7. 

of  Venus,  206. 
Cudbear,  394. 
Cumene,  279,  385. 
Cupric  acetate,  206. 

aceto-metarsenite,  206. 

arsenite,  206. 

carbonate,  206. 

chlorid,  205. 

hydroxid,  205. 

nitrate,  205. 

oxid,  204. 

sulfate,  205. 

sulfld,  205. 
Cuprous  chlorid,  204. 

hydroxid,  205. 

oxid,  204. 

sulfid,  205 

Curare  alkaloids,  481. 
Curarin,  483. 


INDEX 


657 


Cyamelid,  342. 

Cyanamid,  336,  344,  350,  364. 
Cyanhydrin,  ethylene,  293. 
Cyanhydrins,  341. 
Cyanids,  337,  338,  339,  344. 

compound,  344. 

double,  344. 
Cyanobenzene,  422. 
Cyanogen,  337. 

chlorids,  339,  346. 

compounds,  337. 

hydrid,  337. 

oxygen  compounds  of,  342. 

sulfhydrate,  343. 

sulfur  compounds  of,  342. 
Cyclamin,  411. 

Cyclic  compounds,  227,  257,  378. 
Cyclodiolefln,  379. 
Cyclohexadienes,  379,  431. 
Cyclohexanes,  431. 
Cyclohexatriene.  379. 
Cyclohexenes,  379,  431. 
Cycloparaffins,  379. 
Cyclotriolefln,  379. 
Cymene,  387,  392,  437. 
Cymogene,  232. 
Cystem,  367. 
Cystin,  367,  593,  617. 
Cysts,  hydatid,  288. 
Cytisin,  472,  478. 

Dahlia,  451. 
Dambonite,  434. 
Dambose,  434. 
Daphnetin,  412,  463,  464. 
Daphnin,  411. 
Decahydroquinolin,  468. 
Deep  waters,  70. 
Dehydromorphin,  485. 
Deliquescence,  18. 
Density,  4. 
Deodorizers,  401. 
Deoxidation,  62. 
Desoxystrychnin,  482. 
Deuteroalbumoses,  518. 
Deuteroelastoses,  508. 
Deuterogelatoses,  519. 
Dextrin,  242,  246,  275. 
Dextrins,  268,  273,  275,  276. 
Dextrogyrous  substances,  25. 
Dextrose,  294. 
Diabetic  sugar,  268. 
Diacetamid,  346. 
Diacetic  glucose,  320. 
Diacetyl  ethylene  diamin,  333. 

urea,  351. 
Diacetylene,  229. 

series,  229. 
Diacidyl  urei'ds,  351. 
Diacetonamin,  360. 
Dialdehydes,  261,  285. 
Dialysis,  20. 
Diamid,  105. 
Diamidogen,  337. 
Diamido-diphenyl,  384,  446,  447. 
Diamido-triphenyl  carbinol,  450. 

methanes,  449. 
Diamids,  334,  345,  348. 
Diamins,  255,  326,  329,  330,  333,  493,  501. 

dibenzoyl  compounds  of,  415. 

primary,  330. 

secondary,  330. 

42 


Diamins,  tertiary,  330. 
Diammonium  chlorids,  334. 
Diamond,  141. 
Diastase,  242,  270,  273,  276. 
Diazins,  461,  462. 
Diazoamido  benzene,  427,  429. 
Diazoamido  compounds,  426,  427. 
Diazobenzene,  426. 

chlorid,  427,  429,  446. 

sulfate,  427. 
Diazo  compounds,  389,  417,  426. 

dyes,  428. 
Diazoles,  456. 
Diazonaphthalene  compounds,  446. 

nitrate,  443. 
Diazo  salts,  428,  429. 
Dibenzenic  compounds,  409. 
Dibenzo  pyrones,  464. 

pyrrole,  467. 
Dibenzoyl,  449. 
Dibenzyl,  447. 
Dibromoparaffins,  379. 
Dibromopropylene,  372. 
Dibutyraldin,  473. 
Dicacodyl,  368. 
Dichloranilins,  421. 
Dichlohydrin,  371. 
Dichlormethane,  233. 
Dichlornaphthalene,  441. 
Dichlorobenzenes,  387. 
Dichloro-naphthoquiuone,  443. 
Dicyanids,  285. 
Dicyanogen,  342. 
Didymium,  39. 
Diethyl  acetamid,  345. 

sulflte.  313. 

amin,  329. 

benzenes,  386. 

carbinol,  241. 

Diethylene  diamin,  330,  462. 
Diffusion,  20. 

of  gases,  61. 
Difluor  diphenyl,  446. 
Digestion,  512-538. 
Digitalin,  412. 
Digitalis  glucosids,  412. 
Digitaliresin,  412. 
Digitalose,  412. 
Digitogenin,  412. 
Digitoneiin,  412. 
Digitonin,  412. 
Digitoxin,  412. 

Diheteroatomic  compounds,  453. 
Dihydro  benzene,  379. 

benzenes,  431. 

collidin,  493. 

cymenes,  432. 

furfurane,  454. 

lutidin,  493. 

pyrazole,  456. 

pyridins,  461. 

pyrrole,  455. 

quinolins,  468 

strychnolin,  482. 
Diimins,  329,  334. 
Diindoxyl,  466. 
Diiodo-thymol,  392. 
Diketones,  262. 

aromatic,  400. 
Dimetadioxytoluene,  394. 
Dimethoxyisoquinolin,  488. 
Dimethylamin,  328,  329. 


658 


INDEX 


Dimethyl  anilin,  448,  450,  451. 

anthracene,  442. 

arsin,  367. 

benzenes,  386,  387. 

ethylbenzenes,  386. 

ethyl  carbinol,  238,  241. 

diacetylene,  229. 
Dimethylia,  328. 
Dimethyl  indole,  465. 

oxyphthalid,  407. 

phenols,  391. 

pyridins,  460. 

pyrocatechol,  394. 

xanthins,  358. 
Dimorphism,  12. 
Dimyricyl,  229. 
Dinitranilins,  421. 
Dinitrils,  341. 
Dinitro  benzene,  417. 

naphthol,  443. 

phenols,  418. 
Dinitroso-resorcinol,  419. 
Dioleflns,  371. 
Diolefln  ketones,  373. 

series,  229. 
Dioxindole,  424,  466. 
Dioxy  anthracenes,  444. 

anthraquinone,  445. 

coumarin,  412. 

ethylene  amin,  330. 

methylanthraquinone,  445. 

purin,  356,  359. 
Dipentene,  432,  435. 

nitrosochlorid,  431. 
Diphenyl,  439,  441,  446. 

acetylene,  447.  448. 

acetylenes,  447. 

amin,  467. 

benzene,  446. 

carbinol,  448. 

diacetylene,  448. 

diethylenediamin,  462. 

ethanes,  447. 

ethylenes,  447. 

hydrazin,  428. 

imid,  467. 

ketone,  448. 

m-toluyl  carbinol,  448. 

methane,  384,  439,  447. 

olefins,  447. 

oxid,  409. 

paraffins,  447. 

phthalid,  449. 
Diphenylene,  439. 

derivatives,  453. 

diketone,  441,  444. 

diphenylethane,  439. 

imid,  439,  463,  467. 

ketone,  444. 

methane,  439. 

oxid,  439,  446. 

sulfld,  439,  446. 
Dippel,  oil  of,  455,  459,  460. 
Dipropargyl,  229. 
Dipyridyl,  453. 

compounds,  469. 
Dipyridyls,  469. 
Disaccharids,  263,  270,  535. 
Disacryl,  372. 

Disdiazoamido  compounds,  427. 
Disinfectants,  501. 
Dispersion,  21. 


Dissociation,  69. 

electrolytic,  30,  44. 
Distillation,  18. 
Diurea,  353,  462. 

carbonyl,  353. 
Diureids,  350,  353. 
Dolomite,  193,  194. 
Double  decomposition,  43. 

salts,  52. 
Dulcin,  255. 
Dulcitan,  255. 
Dulcite,  255. 
Dulcitol,  255,  296,  297. 
Dulcose,  255. 
Dutch  liquid,  316,  369. 
Dynamite,  317. 
Dyslysin,  527,  537. 

Ebullition,  18. 
Ecbolin,  492. 
Ecgonin,  461,  477. 
Efflorescence,  12. 
Egg  albumen,  503. 
Elastin,  498,  508,  519. 
Elayl,  368. 

chlorid,  316. 
Electrical  current,  26. 
Electricity,  26. 
Electrochemical  equivalent,  30. 

series,  29. 
Electrodes,  27. 
Electrolysis,  28. 
Electrolyte,  28. 

Electrolytic  dissociation,  30,  44. 
Electromotive  force,  27. 
Electronegative,  28. 
Electropositive,  28. 
Elements,  30,  36. 

acidulous,  57,  79. 

amphoteric,  57. 

basylous,  57,  58,  168. 

classification  of,  56. 

typical,  57,  59. 
Eleoptenes,  433. 
Eleutriation,  191. 
Emerald,  198,  202. 

green,  147. 
Emery,  199. 
Emetin,  472,  493. 
Emodin,  412,  445. 
Empirical  formulae,  53. 
Emulsin,  270,  410. 
Emulsions,  318. 
Enzymes,  243,  513. 

amylolytic,  514. 

diastatic,  275,  513,  514. 

of  blood,  543. 

pancreatic,  273,  275. 

proteolytic,  500,  514. 

salivary,  273,  275,  513,  514. 
Eosin,  396. 
Epi  compounds,  442. 
Epiguanin,  356,  358. 
Epsom  salt,  194. 
Equations,  40,  41,  48. 
Equivalence,  39. 
Equivalent,  40. 

conductivity,  44. 

weight,  40. 
Equivalents,  33,  34. 
Erbium,  29,  36,  58. 
Eremacausis,  502. 


INDEX 


659 


Ergotin,  492. 

Erythrin,  254. 

Erythrite,  254. 

Erythrodextrin,  276. 

Erythroglucin,  254. 

Erythrol,  240,  254,  264,  293,  454. 

tetracetyl,  319. 

tetranitro,  319. 
Erythrose,  264. 
E serin,  493. 
Essence  of  bitter  almonds,  artificial,  417. 

of  Mirbane,  417. 
Essences,  318,  431. 
Ester,  acetoacetic,  293,  313. 

alkaloids,  471,  475. 

raalonamic,  361. 

methylene  malonic,  375. 

nitroacetic,  362. 

sulfates,  589. 

Esters,   239,  241,  248,   291,   299,   311,   328, 
346. 

acetoacetic,  457. 

acid,  311. 

alcohol,  311. 

aromatic,  403. 

beta-ketonic,  298,  313. 

carbonic,  346. 

cyanic,  278. 

cyclic,  320. 

dioxymalonic,  298. 

glyceric,  282,  283,  294,  316. 

haloid,  233,  241,  312,  340. 

hydrocyanic,  340. 

hyposulfurous,  313. 

isocyanic,  327,  340,  344,  350. 

isothiocyanic,  343. 

menthyl,  435. 

nitric,  327. 

nitrous,  325. 

of  aldoalcohols,  319. 

of  beta-ketone  acids,  457. 

of  dihydric  alcohols,  315. 

of  glucose,  320. 

of  glycols,  315. 

of  glycerols,  253,  316,  317. 

of  hexoses,  320. 

of  ketoalcohols,  319. 

of  mannitol,  255. 

of  monohydric  alcohols,  312. 

of  oxyacids,  320. 

of  polyhydric  alcohols,  319. 

of  trihydric  alcohols,  316,  317. 

oxymalonic,  298. 

phenyl,  389,  391. 

phenylhydrazone  acetoacetic,  457. 

sulfurous,  313. 
Ethal,  251,  284. 
Ethane,  370. 
Ethanol,  240. 
Ethene,  368,  370. 

chlorhydrin,  252. 

chlorid,  237. 

compounds,  369. 

glycol,  252,  369. 

homologues  of,  369. 

series,  368. 
Ethenes,  368. 
Ethenyl,  227. 

amidoxim,  335. 
Ether,  acetic,  313. 

alkaloids,  453,  471,  475. 

allylic,  376. 


Ether,  diethylene  glycol,  301. 

ethylic,  300,  312. 

ethylphenyl,  390. 

glycolethyl,  301. 

hydrobromic,  237. 

hydrochloric,  237. 

hydriodic,  237. 

methylene  diethyl,  323. 

methylphenyl,  390. 

nitric,  311,  312. 

nitrous,  244,  245,  312. 

phenyl,  409. 

propargylethyl,  376. 

pyroacetic,  262. 

sulfuric,  300,  312. 
Ethers,  299. 

compound,  299,  311. 

haloid,  233. 

mixed,  299,  409. 

of  glucose,  320. 

of  glycol,  301. 

phenyl,  390,  391,  409. 

simple,  237,  299. 
Ethidene,  227. 

chlorid,  369,  370. 

compounds,  369. 

diethyl  sulfone,  323. 

iodid,  370. 
Ethine,  227,  370. 

series,  370. 
Ethol,  315. 
Ethyl,  227. 

acetate,  313,  346,  348. 

acetoacetate,  313. 

acetylsodacetate,  314. 

amin,  327,  329,  340. 

benzene,  386,  387. 

betaoxybutyrate,  314. 

borate,  140. 

bromid,  237,  368,  369. 

carbinol,  248. 

chlorid,  153,  237,  301. 

coniiin,  473. 

cyanid,  281,  340. 

formate,  347. 

hydroxid,  242. 

iodid,  237,  244,  369. 

isocyanate,  344. 

isocyanid,  340. 

mercaptan,  321. 

mercaptol,  323. 

methylpyridin,  481. 

morphin,  484. 

naphthalene,  440. 

nitrate,  311,  312. 

nitrite,  312. 

orthocarbonate,  335. 

oxalate,  348. 

oxid,  300,  315. 

phenols,  392. 

phenyl  ether,  390. 

pyridins,  460. 

strychnin,  482. 

sulfate,  301,  312,  313. 

sulfhydrate,  321. 

sulfid,  321,  322. 

sulfone,  322. 

sulfoxid,  322. 

thallin,  468. 

thioalcohol,  321. 

trim  ethyl  ammonium  hydroxid,  332. 

urea,  350. 


660 


INDEX 


Ethyl,  urethan,  346. 
Ethylates,  244. 
Ethylene,  316,  368. 

benzene,  387. 

bichlorid,  316. 

bromid,  370. 

chlorhydrin,  301,  315,  316,  330. 

eWorld,  316,  368,  369,  371. 

compounds,  309. 

cyanhydrin,  293. 

cyanid,  288,  330,  342. 

diamin,  333,  334. 

ethenyl  amidin,  333. 

glycol,  239,  252,  316. 

imid,  453. 

imin,  334. 

naphthalene,  440. 

oxid,  301,  315,  453. 

sulfld,  453. 

Ethylidene  compounds,  369. 
Eucalypteol,  435. 
Eucalyptol,  435. 
Eugenol,  395. 
Euphorine,  347. 
Evaporation,  17. 
Exalgine,  422. 
Excretion,  537. 
Extractives,  542. 

Faces,  537. 

Farad,  28. 

Fats,  253,  318,  535,  542. 

phosphorized,  319. 

saponification  of,  514. 
Fatty  compounds,  227,  229. 
Feldspar,  198,  201. 
Fermentation,  243,  305. 

acetic,  243,  280. 

alcoholic,  242,  243,  264,  273. 

butyric,  282. 

lactic,  243,  273,  292. 

sulfhydric,  92. 
Ferments,  false,  243. 

soluble,  513. 

true,  243. 

unorganized,  513. 
Ferrates,  152. 
Ferric  acetate,  154. 

acid,  152. 

bromid,  153. 

chlorid,  153. 

citrate,  155. 

disulfld,  152. 

ferrocyanid,  156. 

hydrates,  151. 

hydroxid,  151. 

iodid,  153. 

nitrates,  154. 

oxid,  151. 

oxychlorid,  153. 

oxyhydrate,  152. 

phosphate,  154. 

pyrophosphate,  154. 

sulfates,  153. 

sulfid,  152. 

tartrate,  155. 
Ferricyanids,  345. 
Ferrocyanids,  345. 
Ferrous  acetate,  154. 

bicarbonate,  155. 

bromid,  153. 

carbonate,  155. 


Ferrous  chlorid,  151,  152. 

ferricyanid,  156. 

hydrates,  151. 

iodid,  153. 

lactate,  155. 

nitrate,  154. 

oxalate,  155. 

oxid,  151. 

phosphates,  154. 

sulfate,  151,  153. 

sulfld,  152. 

tartrate,  155. 
Fibrin,  279,  498,  539,  541,  554. 

ferment,  540,  541. 
Fibrinogen,  497,  540,  552. 
Fibrinoplastic  substance,  541. 
Fibroin,  508. 
Firedamp,  231. 
Five-membered     heterocyclic    compounds, 

454. 

Flake  white,  163. 
Flash  point,  232. 
Flavanilin,  421. 
Flavin,  413. 
Flint,  144. 

Flowers  of  sulfur,  71. 
Fluorene,  438,  439,  441,  442,  444,  446,  462. 

alcohol,  444. 

ketone,  444. 
Fluorescem,  394,  396. 
Fluorin,  29,  36,  57,  79. 
Formal,  252,  261. 
Formaldehyde,  242,  257,  448. 
Formalin,  257. 
Formamid,  347. 
Formin,  360. 
Formonitril,  337,  340. 
Formulae,  40. 

algebraic,  218. 

empirical,  41,  53. 

general,  218. 

graphic,  53,  55. 

rational,  53. 

typical,  53. 
Formyl  bromid,  236. 

chlorid,  234. 

hybrid,  257. 

iodid,  236. 
Fossil  wax,  232. 
Frangulin,  412. 
Fraunhofer's  lines,  22. 
Fraxetin,  412. 
Fraxin,  412. 

Freezing  point,  14,  17,  68,  223. 
Fructose,  265,  269,  270,  430,  559,  614. 
Fruit  sugar,  269. 
Fuchsin,  451. 
Fucose,  265. 
Fulminates,  245. 
Fulminating  gold,  343. 

mercury,  343. 

silver,  343. 
Functions,  42. 
Furane,  458. 
Furfuraldehyde,  454. 
Furfurane,  452,  453,  454,  456. 
Furfurole,  265,  349,  454, 
Furole,  454. 
Furo-monazoles,  456. 
Fusel  oil,  249. 
Fusing  point,  14. 
Fusion,  14. 


INDEX 


661 


Gadinin,  319. 

Galactose,  265,  269,  272,  275,  559. 

Galena,  157,  159. 

Gallem,  395. 

Gallisin,  268,  273. 

Gallium,  29,  36,  58,  198,  202. 

Galvanic  cell,  27. 

circuit,  27. 

electricity,  26. 
Garnet,  198. 
Gas,  102. 

coal,  302. 

lights,  307. 

tar,  385. 

water,  303. 
Gases,  19. 

absorption  by  liquids,  562. 

diffusion  of,  61. 

partial  pressure  of,  563. 

permanent,  19. 

weight  of,  61. 
Gasolene,  232. 

Gastric  juice  (and  gastric  digestion),  515- 
525. 

abnormal  variations  of,  520. 

acetic  acid  in,  520. 

acetone  in,  520. 

acid  salts  in,  521,  522. 

action  on  proteins,  516,  517,  518,  519. 

anachlorhydria,  520. 

analysis  of,  515. 

arsenic  in,  520. 

bile  in,  520. 

Boas'  method,  523. 

butyric  acid  in,  520,  524. 

chlorids  in,  522. 

chymosin  in,  520,  524. 

chymosinogen  in,  520,  524. 

dimethyl  -  amido  -  azobenzene    reaction, 
522. 

effective  hydrochloric  acid  of,  522,  523. 

enzymes  of,  515,  516. 

examination  of,  521. 

fermentations,  effects  upon,  520. 

free  hydrochloric  acid  in,  515,  516,  521, 
522,  523. 

free  acids  of,  515,  516,  521. 

haematin  in,  520. 

hyperchlorhydria,  520. 

hypochlorhydria,  520. 

lactic  acid  in,  516,  520. 

Martius  and  Ltittke's  method,  522. 

morphin  in,  520. 

native  albumens  in,  525. 

organic  acids  in,  516,  520,  521,  522. 

pepsin  in,  515,  516,  524. 

pepsinogen  in,  516,  517,  524. 

pepsohydrochloric  acid  of,  517,  519. 

peptones  in,  525. 

phloroglucin-vanillin  reaction,  521. 

primary  albumoses  in,  525. 

products  of  digestion  in,  524. 

protein  hydrochloric  acid  in,  521,  522. 

resorcin-sugar  reaction,  522. 

secondary  albumoses  in,  525. 

syntonin  in,  525. 

Topfer's  method,  522. 

total  acidity  of,  521,  522. 

urea  in,  520. 
Gelatin  in,  279,  363,  508,  519. 

explosive,  277 
Gelatose,  519. 


Geneva  names,  226. 
Geraniol,  372,  373. 
German  silver,  203. 
Germanium,  29,  36,  57. 
Germicides,  501. 
Glass,  soluble,  172. 

water,  172. 
Glauber's  salt,  171. 
Gliadin,  509. 
Globin,  548,  550. 
Globulins,  497,  503,  601. 

coagulated,  498. 

vegetable,  509. 
Globuloses,  518. 
Glonoin,  316. 
Glucase,  513,  514.  543. 
Glucinum,  36,  202. 
Gluconic  lactone,  268,  269. 
Gluconolactone,  294. 
Glucononitril,  294. 
Glucosazone,  269. 

Glucose,  242,  246,  265,  268,  270,  275,  294, 
299,  320,  321,  409,  430,  558,  559, 
607-614. 

di acetic,  320. 

esters  of,  320,  409. 

ethers  of,  320,  409. 

in  blood,  542,  543,  544. 

tetracetic,  320. 

triacetic,  320. 
Glucoses,  255,  265. 
Glucosid,  phenyl,  320. 
Glucosids,  265/320,  409,  434. 
Glucosyl  phenate,  320,  410. 
Glucovanillin,  411. 
Glue,  508. 
Gluten,  509. 

casein,  509. 

fibrin,  509. 

proteids,  509. 
Glycerids,  253,  316. 
Glycerine,  252,  253. 
Glycerites,  253. 

Glycerol,  240,  242,  252,  253,  264,  293,  295, 
371,  372. 

halohydrins,  316. 

ketone,  256. 

mesitylene,  398. 
Glycerols,  252,  253,  290,  316. 
Glycin,  363. 

Glycocoll,  357,  363,  425,  508,  526,  527,  530, 
578. 

anhydrid,  363. 
Glycocolls,  362. 

Glycogen,  273,  275,  293,  542,  558,  559. 
Glycol,  252,  293,  301,  330. 

acetates,  315. 

alphapropylene,  292. 

diacetic,  251. 

ethene,  252. 

ethers  of,  301. 

ethylene,  239,  252,  316. 

ethyl  ether,  301. 

halohydrins,  315. 

haloid  esters  of,  315. 

methene,  252. 

monoacetic,  251. 

monothioethylene,  321. 

propyl,  240,  288. 

toluylene,  449. 
Glycollid,  363. 
Glycols,  251,  290,  316,  360. 


662 


INDEX 


Glycols,  esters  of,  315. 

xylylene,  398. 
Glycolyl  urea,  351,  364. 
Glycolyse,  543. 

Glycoproteids,  498,  504,  505,  519. 
Glycoproteins,  499. 
Glyoxal,  239,  256,  261,  292. 
Glycosuria,  543,  559,  607. 
Gold,  29,  36,  57,  146. 

trichlorid,  146. 
Goulard's  extract,  160. 
Gram,  3. 
Granulose,  275. 
Grape  sugar,  268. 
Graphic  formula,  53,  55. 
Graphite,  141. 
Green  oil,  385. 
Ground  waters,  70. 
Guaiacol,  391,  393. 
Guanidin,  335,  336,  349,  357. 
Guanin,  335,  354,  356,  357,  359. 
Guano,  190,  354,  357. 
Guaranin,  358. 
Gulose,  265. 
Gum,  British,  275. 

resins,  438. 
Gums,  273,  275. 
Gunpowder,  177. 

smokeless,  317. 
Guvacin,  478. 
Gypsum,  188,  190. 

Hfiematin,  520,  548,  550. 
Haematinometer,  556. 
Haematite,  150. 
Haematocrit,  537. 
Haematoidin,  528,  551. 
Haematoporphyrin,  551,  591,  604. 
Haematuria,  549,  604. 
Haemin,  550. 

Haemochromogen,  548,  550. 
Haemoglobin,  520,  545,  54<i,  556,  604. 

carbon  monoxid,  302,  549. 

reduced,  546. 
Haemoglobinometers,  556. 
Haemoglobins,  498,  505. 
Haemoglobinuria,  549,  604. 
Hair  balls,  538. 

dyes,  158. 
Halogens,  79. 
Halohydrins,  315,  316. 
Haloid  esters,  233. 

ethers,  233. 

salts,  43. 

Hausmannite,  148. 
Heat,  13. 

atomic,  37. 

latent,  15,  18. 

specific,  19. 
Heavy  carburetted  hydrogen,  368. 

oil,  385. 

spar,  192. 

Helicoproteid,  508. 
Helleboreiin,  412. 
Helleborescin,  412. 
Helleboretin,  412. 
Helleborin,  412. 
Helium,  36,  62. 
Hemialbumosos,  518,  519. 
Hemipeptone,  .010. 
Hemiterpenes,  431. 
Heptoses,  264. 


Hesperetin,  413,  463,  464. 

Hesperidin,  412. 

Heteroalbumoses,  518. 

Heterocyclic  compounds,  228,  378,  452. 

Heteroxanthin,  356,  358,  359. 

Hexacetyl  mannitol,  319. 

Hexacarbocyclic  compounds,  379,  380. 

Hexachlorethane,  237. 

Hexadiene,  379. 

Hexahydro  benzene,  379,  384,  431. 

cymene,  433,  434. 

phenol,  436. 

pyrazin,  462. 

pyridins,  459,  460,  461. 
Hexamethylene,  379. 

diamin,  333. 

tetramin,  360. 
Hexanitro  mannitol,  320. 
Hexites,  255. 

Hexon  bases,  336,  349,  366,  499,  578. 
Hexoses,  264,  265, 

esters  of,  320. 

pentabenzoyl  compounds,  415. 
Histidin,  499. 
Histon,  500,  506. 
Hofmann's  violet,  401. 
Homatropin,  477. 
Homologous  series,  218. 
Horn  lead,  157. 
Humus,  502. 

Hyaline  substance  of  Rovida,  552. 
Hydantoin,  351. 

methyl,  352. 
Hydracetin,  431. 
Hydracids,  42. 
Hydramins,  329,  330,  360. 
Hydrastin,  408. 
Hydrastis  alkaloids,  472. 
Hydrates,  69. 
Hydrasin,  104,  105,  353,  427. 

compounds,  428. 
Hydrazins,  337,  360,  417. 

unsymmetrical,  429. 
Hydrazobenzene,  428,  447. 
Hydrazo  compounds,  428. 
Hydrazones,  360,  429,  436,  444,  457. 
Hydrids,  230. 
Hydrindene,  439. 
Hydrindones,  444. 
Hydroaromatic  compounds,  431. 
Hydrobenzoin,  449. 
Hydrobilirubin,  528,  537. 
Hydrocarbon  hydroxids,  23!». 
Hydrocarbons,  219,  227,  229. 

acetylene  series,  370. 

condensed,  439. 

diolefin  series,  371. 

ethene  series,  368. 

ethine  series,  370. 

heptacarbocyclic,  379. 

hexacarbocyclic,  380. 

hydroaromatic,  431. 

methane  series,  229. 

monobenzenic,  385. 

olefln  series,  368. 

pentacarbocyclic,  379. 

tetracarbocyclic,  379. 

tricarbocyclic,  379. 

saturated,  218,  229. 
Hydrocotarnin,  487,  489. 
Hydrogen,  29,  36,  57,  59. 

antimonid,  136. 


INDEX 


663 


Hydrogen  arsenids,  123,  128,  132. 

arseniuretted,  123. 

bromid,  87. 

chlorid,  83. 

cyanid,  337. 

dioxid,  77. 

fluorid,  79. 

iodid,  89. 

monosulfld,  92. 

nitrid,  104. 

pentasulfld,  94. 

peroxid,  64,  77,  169. 

phosphids,  118. 

polysulflds,  94. 

silicid,  144. 

sulfld,  95. 

sulfuretted,  92. 
Hydrolysis,  70,  312. 
Hydrometer,  5,  6. 
Hydronaphthalenes,  440. 

pyridins,  461. 

pyrrole  derivatives,  455. 

quinol,  437. 

quinolins,  468. 

quinone,  394,  411. 

sulflds,  43,  94. 

terpenes,  433. 
Hydroxids,  42,  69. 
Hydroxylamin,  105,  256,  335,  360,  361,  466. 

compounds,  325. 

Hydroxylammonium  compounds,  105. 
Hygrins,  456,  470,  472. 
Hygrometry,  103. 
Hyoscin,  475,  478. 
Hyoscyamin,  472,  475,  478. 
Hyperglyceemia,  325. 
Hypnone,  400. 
Hyperchlorhydria,  573. 
Hypophosphites,  120. 
Hypoxanthin,  354,  356,  357,  359. 

Iceland  spar,  190. 
Icthyulin,  506. 
Ichthylepidin,  508. 
Ictbyol,  323. 
Idose,  265. 
Imidoparaffins,  326. 
Imids,  334,  346,  347. 
Imin  bases,  326. 
Imins,  329,  334. 
Indene,  438,  439,  441,  462. 
Index  of  refraction,  21. 
Indican,  413,  466,  590. 

urinary,  466,  536. 
Indicanin,  413. 
Indicanuria,  590. 
Indiglucin,  413. 
Indigo,  404,  424,  465.  466,  590. 

blue,  413,  448,  462,  465,  466. 

carmine,  467. 

compounds,  464. 

white,  466. 
Indigotin,  466. 
Indium,  29,  36,  58,  198,  202. 
Indoanilin  dyes,  397. 

Indole,  439,  453,  462,  463,  464,  470,  493,  499, 
536. 

homologues  of,  464. 
Indone,  444. 
Indophenin,  455. 
Indoxyl,  466,  466. 

sulfates,  590. 


Indulin  dyes,  397. 

Indulins,  459. 

Inosite,  434,  615. 

Insulators,  27. 

Intestine,  bacterial  action  in,  535,  536. 

chemical  changes  in,  535. 

concretions  in,  538. 

gases  of,  537. 

secretions,  535. 
Inulin,  269,  275. 

dyes,  428. 

Inversion,  270,  272,  535. 
Invertin,  270,  410,  535. 
Invert  sugar,  269. 
lodanilins,  421. 
lodids,  90. 
lodin,  29,  36,  57,  79,  88. 

chlorids  of,  90. 

greens,  451. 

number,  374. 

oxyacids  of,  90. 
lodoform,  236,  244,  245,  370. 
lodol,  455. 
lodophenols,  393. 
lodoquinin  sulfate,  479. 
lonization,  30,  44. 
Ions,  29,  44. 

Iridium,  29,  36,  57,  166. 
Iron,  29,  36,  57,  147,  150. 

acetates,  154. 

bromids,  153. 

cast,  150. 

chlorids,  152. 

citrates,  155. 

compounds,  151. 

galvanized,  151. 

hydrates,  151. 

iodids,  153. 

magnetic  oxid,  151. 

nitrates,  154. 

oolitic,  150. 

ores,  150. 

oxids,  151. 

passive,  111,  151. 

perchlorid,  153. 

peroxid,  151. 

phosphates,  154. 

pig,  150. 

protoxid,  151. 

reduced,  151. 

rust,  151. 

salts,  153. 

sesquichlorid,  153. 

sesquioxid,  151. 

spathic,  150,  155. 

sulfates,  153. 

sulflds,  152. 

tartrates,  155. 

wrought,  150. 
Isatin,  403,  424,  466,  467. 
Isatoxin,  466. 
Iso  acetonitril,  341. 

alcohols,  240. 

benzonitril,  341,  422. 

butane,  285. 

butylamin,  328. 

butyl  carbinol,  238,  241. 

cholesterol,  530. 

cholin,  331,  332. 

compounds,  230. 

coumarin,  463,  464. 

cyanates,  343. 


664 


INDEX 


Iso  acetonitril  cyanids,  328,  340. 

dulcite,  265. 

indole,  462,  463,  465. 

maltose,  268,  273,  514,  543. 
Isomeres,  219. 
Isomerism,  219,  381. 
Isomery,  place,  290. 

position,  290. 

space,  266,  295. 

stereo,  266,  295. 
Isomorphism,  11. 
Iso  nicotin,  469. 

nitrils,  328. 

pentane,  238. 

preue,  371. 

propyl  alcohol,  240. 
amin,  361. 
benzene,  386. 

quinolin,  432,  463,  467,  468. 

alkaloids,  472,  484. 
Ivory  black,  142. 

Jaboramdin,  478. 
Jaborin,  478. 
Jalapin,  413. 
Jalapinol,  413. 
Japaconin,  492. 
Japaconitin,  492. 
Javelle  water,  177. 
Jecorin,  541,  543,  544. 
Jervin,  492. 
Jet,  141. 
Jeweler's  rouge,  151. 

Kairin,  468. 

Kaolin,  201. 

Kata  compounds,  442. 

Kathode,  27. 

Kelp,  88. 

Keratins,  498,  503,  507,  519. 

Kermes  mineral,  138. 

Kerosene,  232. 

Keto  alcohols,  429. 

hexoses,  255. 

hydrazones,  430. 

hydro-p-cymenes,  436. 

menthadienes,  436. 

menthans,  436. 

menthenes,  436. 
Ketone,  262. 

acids,  277,  291,  298,  429. 

alcohols,  255,  262. 

dimethyl,  261,  262. 

diphenyl,  448. 

diphenylene,  444. 

fluorene,  444. 

glycerol,  256,  264. 

methylethyl,  261. 

naphthylmethyl,  444. 

phenylmethyl,  400. 

pimelin,  436. 

Ketones,  226,  238,  241,  255,  256,  261,  290, 
291,  314,  341,  371,  400,  429,  448. 

aromatic,  400. 

camphan,  436,  437. 

cyclic,  286. 

diolefln,  373. 

hydroaromatic,  434,  436. 

naphthyl,  444. 

nitrogen  derivatives,  360. 

of  condensed  hydrocarbons,  442. 

ring,  436. 


Ketones,  symmetrical,  261. 

terpan,  436. 

unsymmetrical,  261. 
Ketopiperidin,  363. 
Ketoses,  263,  264,  429. 
Ketoxims,  256,  361,  436. 
Kilometer,  3. 
Kilowatt,  28. 
King's  yellow,  127. 
Knock-out  drops,  260. 
Koprosterin,  532. 
Kornei'n,  508. 
Kyanol,  419. 

Labarraque's  solution,  173. 
Lacmoid,  394. 
Lactalbumin,  497,  624. 
Lactamid,  362,  364. 
Lactams,  361,  362,  424. 
Lactids,  291,  292,  320. 
Lactin,  272. 
Lactoglobulin,  624. 
Lactometer,  621. 
Lactone,  deltagluconic,  321. 

gluconic,  269. 
Lactones,  265,  294,  320,  373,  449,  458. 

naphthalic,  545. 
Lactose,  270,  272,  559,  614. 
Lsevogyrous  substances,  25. 
Lsevulose,  269. 
Laiose,  614. 
Lakes,  199. 
Lamp-black,  142. 
Lana  philosophica,  196. 
Lanolin,  529. 
Lanthanum,  29,  36,  58. 
Latent  heat,  15,  18. 
Laughing  gas,  106. 
Lauth's  violet,  459. 
Law  of  Ampere,  34. 

Avogadro,  34. 

Dalton,  31. 

definite  proportions,  31. 

Dulong  and  Petit,  37. 

Faraday,  30. 

Gay  Lussac,  33. 

multiple  proportions,  32. 

Ohm,  28. 

periodic,  202. 

Raoult,  17. 

reciprocal  proportions,  32. 
Lead,  29,  36,  57,  157. 

acetates,  159. 
sesquibasic,  160. 
sexbasic,  160. 

action  of  water  on,  157. 

carbonates,  160. 

chlorid,  159. 

chromate,  159. 

dioxid,  158. 

iodid,  159. 

monoxid,  158. 

nitrate,  159. 
basic,  159. 

oleate,  158. 

orthonitrate,  159. 

oxids,  158. 

oxychlorids,  159. 

oxy  iodid,  159. 

peroxid,  158. 

plaster,  318. 

pyronitrate,  159. 


INDEX 


665 


Lead,  red,  158. 

salts  of,  159. 

subsulfate,  159. 

sugar  of,  159. 

sulfate,  159. 

sulfid,  159. 

white,  160. 
Leather,  508. 
Lecithalbumens,  504. 
Lecithins,  319,  330,  503,  542,  553. 
Legurain,  509. 
Lepidin,  481. 

p-raethoxy,  481. 
Lepidins,  468. 
Lepidolite,  183. 
Lethol,  315. 

Leucanilin  carbinols,  450. 
Leucanalins,  450. 
Leucems,  499. 
Leucin,   203,   364,   413,   424,  519,  544,  578, 

617. 

Leucins,  364,  499. 
Leucocytes,  519. 
Leucoma'ins,  337,  496. 
Leucomalachite  green,  450 
Leuco-pararosanilin,  447. 
Levigation,  191. 
Leyden  crystals,  334. 
Lichenin,  275. 
Light,  21. 

actinic  power  of,  26. 

chemical  effects  of,  26. 

oil,  385. 

polarized,  24,  265. 

wave-lengths  of,  23. 
Lime,  188. 

chlorid  of,  82,  189. 

milk  of,  189. 

slaked,  189. 

stone,  188,  190. 

water,  189. 
Limonene,  435. 

nitrosochlorids,  436. 

tetrabromids,  432. 
Limonenes,  432. 
Linalool,  372,  432. 
Linkage,  224. 
Lipochroms,  544. 
Liquefaction,  18. 
Liquid  of  Libavius,  166. 
Litharge,  158. 
Lithium.  29,  36,  58,  168. 

bromid,  168. 

carbonate,  168. 

chlorid,  168. 

hydroxid,  168. 

oxid,  168. 

urate,  168,  355. 
Litmus,  394. 
Liver  sugar,  268. 
Loadstone,  151. 
Lubricating  oils,  232. 
Lunar  caustic,  184. 
Luteiins,  544. 
Lutidins,  460. 
Lycin,  332. 
Lycoctonin,  491. 
Lyons  blue,  451. 
Lysatin,  336,  349,  499. 
Lysatinin,  336,  499. 
Lysidiu,  333. 

urate,  355. 


Lysin,  366,  499. 
Lysol,  391. 

Maclurin,-394,  407. 
Madder,  artificial,  440. 
Magenta,  451. 
Magnesia,  194. 

alba,  195. 
Magnesite,  194. 
Magnesium,  29,  36,  58,  193. 

carbonates,  194. 

chlorid,  194. 

group,  193. 

hydroxid,  194. 

oxid,  194. 

peroxid,  169. 

phosphates,  194. 

pyrophosphate,  194. 

sulfate,  194. 
Malachite,  204,  206. 

green,  450. 
Malonamid,  361. 
Malonamic  ester,  361. 
Malonylurea,  352,  359. 
Malt,  242. 
Maltose,  242,  246,  270,  273,  275,  294,  514, 

543,  559,  614. 
Manganates,  149,  150. 
Manganese,  29,  36,  57,  147,  148. 

chlorids,  149. 

dioxid,  63,  80,  81,  149. 

oxids,  149. 

salts,  149. 

chlorid,  149. 

oxid,  149. 

Manganic  salts,  149. 
Manganite,  148. 
Manganous,  chlorid,  149. 

oxid,  149. 

salts,  149. 

sulfate,  149. 
Mannitan,  255. 
Mannite,  255. 
Mannitol,  240,  255,  268,  294,  296,  319. 

hexanitro,  319. 
Mannose,  265,  268. 
Marble,  188,  190. 
Marsh  gas,  231,  241. 
Martius'  yellow,  443. 
Massicot,  158. 
Matter,  changes  of  state,  13. 

divisibility  of,  7. 

impenetrability  of,  2. 

indestructibility  of,  2. 

states  of,  8. 

weight  of,  2. 

Meconin,  407,  484,  487,  489. 
Meconium,  537. 
Meerschaum,  193. 
Melampyrite,  255. 
Melecitose,  273. 
Melissin,  315. 
Melissyl  palmitate,  315. 
Melitose,  273. 
Menthadiene,  434. 
Menthan,  434. 
Menthene,  433,  434. 
Menthol,  435. 
Menthone,  436. 
Menthoxim,  436. 
Menthyl  chlorid,  433. 
Mercaptal,  321. 


666 


INDEX 


Mercaptals,  323. 
Mercaptan,  313,  321,  323,  536. 
Mercaptids,  321,  322. 
Mercaptols,  323. 
Mercurammonium  chlorid,  212. 
Mercurdiammonium  chlorid,  212. 
Mercuric  chlorid,  210. 

cyanid,  213,  342. 

fulminate,  343. 

iodid,  212. 

nitrate,  213. 

oxid,  63,  209. 

oxychlorids,  209. 

sulfates,  214. 

sulfid,  210. 
Mercurous  chlorid,  210. 

iodid,  212. 

nitrates,  213. 

oxid,  209. 

sulfate,  214. 

sulfid,  210. 
Mercury,  29,  36,  58,  204,  208. 

chlorids,  210. 

formaraid,  347. 

fulminate,  245. 

iodids,  212. 

mercaptid,  321. 

nitrates,  213. 

oxids,  209. 

phenate,  390. 

sulfates,  214. 

sulfids,  210. 

with  chalk,  209. 
Meroquinene,  481. 
Mesitylene,  387. 

glycerol,  398. 
Mesityl  oxid,  373. 
Meso  compounds,  230,  442. 
Mesoxalyl  urea,  298,  362. 
Metachloral,  259. 

chlorophenol,  392. 

compounds,  382,  442. 

cresol,  391. 

dibromobenzene,  383. 

dioxybenzene,  394. 
Metaldehyde,  258. 
Metallocyanids,  344. 
Metalloids,  56. 
Metals,  56,  57. 
Metamerism,  219. 
Metaphenylenediamin,  110,  422. 
Metaphosphates,  121. 
Metastannates.  165. 
Metaxylene,  387. 
Meteoric  waters,  70. 
Meteorites,  150. 
Methacetin,  423. 
Methremoglobin,  549. 
Methane,  231. 

series,  229. 
Methanol,  240. 
Methene  chlorid,  233. 

iodid,  257. 
Methenyl,  227. 

bromid,  236. 

chlorid,  234. 

iodid,  236. 

tricarboxylic  ester,  289. 
Methine,  227. 
Methol,  315. 

Methoxybenzaldehyde,  399. 
Methyl,  227. 


Methyl  acetanilid,  422. 
acetate,  279,  328. 
acetyl  urea,  351. 
amin,  328,  329,  341,  364,  474. 
ammonium  salts,  328. 
anilin,  422. 
anthraquinone,  445. 
arbutin,  411. 
benzene,  384,  386,  447. 
benzoyl  ecgonate,  477. 
blue,  451. 
broraid,  236. 
carbinol,  242. 
carbylamin,  341. 
chlorid,  233. 
conim,  472,  473. 
cyanid,  340,  348. 
dioxyphenanthrene,  489. 
divinyl.  371. 
ethyl  amin,  327. 

benzenes,  386. 

oxid,  299. 

pyridins,  460. 
glycocoll,  336,  362,  364. 
glyoxal,  263. 
guanidin,  335,  336. 
guanins,  358. 
heptenone,  373. 
hydantoiin,  352,  364. 
hydrid,  231,  233. 
hydroxid,  241. 
indoles,  430,  464. 
iodid,  236,  328,  332,  451. 
isocyanid,  340,  341. 
isopropyl  benzenes,  386,  387. 

carbinol,  238,  241. 

ketone,  238. 

phenols,  392. 
morphin,  484,  489. 

methine,  489. 
n-propyl  carbinol,  241. 
oxalate,  241. 
oxethyl  amin,  490. 
oxid,  300. 
penthiophene,  458. 
pentoses,  265. 
phenyl  ether,  390. 

hydrazin,  429. 
pilocarpidin,  478. 
piperidin,  461. 

hydroiodid,  461. 
propyl  benzenes,  386. 
pyridins,  460. 
pyrroles,  455. 
quinin,  480. 
quinolins,  467,  468. 
salicylate,  404. 
strychnin,  482. 
thiophenes,  455. 
uracyl,  453. 
uramin,  335. 
urea,  351. 
xanthins,  358,  359. 
Methylal,  252,  261. 
Methylated  spirit,  242. 
Methylene,  227. 
blue,  451,  459. 
chlorid,  233,  446. 
diamin,  330. 
diethyl  ether,  323. 

sulfone,  323. 
iodid,  368. 


NDEX 


GG7 


Methylene  mercaptal,  323 

oxids,  256. 
Methylia,  328. 
Meter,  3. 

Mica,  193,  198,  201. 
Middle  oil,  385. 
Milk,  273,  621-627. 

abnormal,  625. 

adulterations  of,  621,  625,  62G. 

analysis  of,  626. 

casein  in,  623. 

composition  of,  622,  624. 

corpuscles,  622. 

fat  of,  622. 

human,  624. 

lactalbumin  in,  624. 

lactoglobiilin  in,  624. 

mineral  salts  of,  624. 

of  sulfur,  91. 

opalisin  in,  625. 

physical  properties  of,  621. 

plasma,  622,  623. 

sugar,  269. 
Milliampere,  28. 
Mineral  green,  206. 

poisons,  135. 

waters,  75. 
Minium,  158. 
Miricyl  hydroxid,  251. 
Mispickel,  122. 
Mitis  green,  206. 
Mixtures,  32. 
Molasses,  271. 

beet  sugar,  332. 
Molecular  conductivity,  44,  223. 

weight,  38,  221. 
Molecule,  35. 

Molybdenum,  29,  36,  57,  145. 
Monamids,  327,  344,  345. 

primary,  345,  346,  347. 

secondary,  345,  346,  347. 

tertiary,  345,  346. 
Monamins,  325,  326,  328. 

primary,  326,  327,  329. 

secondary,  326,  327. 

tertiary,  326.  ' 
Monazoles,  456. 
Monobenzenic  compounds,  384,  385. 

hydrocarbons,  385. 
Mono  bromobenzenes,  401,  446. 

chloracetone,  404. 

chloranilins,  421. 

chlorobenzenes,  387. 

heteroatomic  compounds,  453. 

hydrobenzenic  compounds,  384. 

ketones,  aromatic,  400. 

methylpyrocatechuic  ether,  373. 

nitranilins,  421. 

nitrobenzene,  417. 

nitroparaffins,  325. 

nucleate,  heterocyclic  compounds,  454. 

saccharids,  263,  264. 
Monoses,  263,  264. 
Monsel's  salt,  154. 
Monureids,  350. 

monacidyl,  351. 
Morphin,  472,  484,  488,  489. 

acetate,  485. 

chlorid,  485. 

hydrochlorid,  471. 

hydrobromid,  326. 

sulfate,  485. 


Morphium,  471. 
sulfate,  470. 
Morrhuin,  319. 
Mountain  blue,  206. 
Mucedin,  509. 
Mucilages,  275. 
Mucins,  498,  505. 
Mucoids,  505,  506. 
Mucose,  505. 
Mulberry  calculi,  191. 
Murexid,  352,  354,  355. 
Muscarin,  330,  331,  332. 
Mustard  oils,  328,  343,  344,  377. 
Mydalein,  334. 
Mydin,  422. 
Myosin,  497,  504. 
Myrcene,  371. 
Myrosin,  377,  410,  413. 
Mytilitoxin,  495. 

Napellin,  491. 
Naphtha,  232. 

Naphthalene,  279,  385,  402,  438,  439,  444, 
452,  462. 

dyes,  440. 

haloids,  442. 

homologues,  440. 

nitrogen  derivatives,  445. 

phenanthrenes,  439. 
Naphthalenes,  431,  467. 
Naphthenes,  431,  433. 
Naphthol  blue,  459. 

orange,  443. 

yellow,  443. 
Naphthols,  440,  442. 

substituted,  443. 

Naphtholquinones.  440,  444,  446. 
Naphthydrin,  462,  463. 
Naphthyl  alcohols,  444. 

aldehydes,  444. 

amins,  443,  444,  445. 

ketones,  444. 

methyl  ketone,  444. 
Narcei'n,  484,  487,  488,  489. 
Narcotin,    408,     470,    472,    484,    487,    488, 

489. 

Naringenin,  4J3. 
Naringin,  413. 
Nascent  state,  C2. 
Natural  waters,  70. 
Negative  plate,  27. 

pole,  27. 
Neodym,  36,  58. 
Neuridin,  333. 
Neurin,  331,  332. 
Neurokeratin,  507. 
Neutral  reaction,  41. 

salts,  52. 
Nickel,  29,  30,  58,  203. 

sulfate,  203. 

Nicotic  methylbetaiin,  332. 
Nicotidin,  469. 

Nicotin,  456,  460,  461,  470,  472,  473,  493. 
Nil  album,  196. 
Nile  blue,  459. 
Niobium,  29,  36,  57,  144. 
Nitranilins,  421. 
Nitrates,  110,  111. 
Nitre,  176. 
Nitril,  amygdalic,  411. 

bases,  326. 

mandelic,  411. 


668 


INDEX 


Nitrils,  257,  278,  327,   335,   337,   340,  346, 
360,  415. 

aromatic,  401. 

of  carbonic  acid,  342. 

of  dicarboxylic  acids,  341. 

of  ketonic  acids,  341. 

of  oxyacids,  341. 

of  thiocarbamic  acids,  342. 

oxyacid,  294. 
Nitro  acetophenone,  400,  466. 

acids,  361. 

alcohols,  360. 

aldehydes,  360. 

anisols,  418. 

benzene,  419,  428. 

benzenes,  417. 

benzol,  417. 

cellulose,  277,  317. 

cresols,  418. 
Nitrogen,  29,  37,  57,  101. 

bromid,  106. 

chlorid,  106. 

dioxid,  107. 

group,  101. 

iodid,  106. 

monoxid,  106. 

oxids,  106. 

pentoxid,  109. 

tetroxid,  108. 

trioxid,  107. 
Nitro  glycerine,  316. 

ketones,  360. 
Nitrolic  acids,  325. 
Nitro  malonyl  urea,  352,  359. 

naphthalenes,  445. 

naphthols,  443. 

paraffins,  325. 

phenetols,  418. 

phenols,  418. 

toluenes,  417. 
Nitroso  amins,  328,  337,  429. 

benzene,  419. 

phenols,  418. 
Nitrosyl  chlorids,  111. 
Nitrous  fumes,  108. 

oxid,  106. 

Nomenclature,  49,  226,  327. 
Non-metals,  57. 
Nonoses,  264. 
Normal  compounds,  230. 
Nubecula,  566. 
Nuclei,  227. 

Nucleic  acids,  506,  507. 
Nuclein  bases,  356. 
Nucleins,  319,  356,  498,  506,  507. 
Nucleoalbumens,  497,  504,  519. 
Nucleohiston,  498,  506,  552,  554. 
Nucleoproteids,  265,  356,  498,  504,  505,  506, 

519,  578. 
Nucleus,  378. 

Occlusion,  61. 
Octoses,  264. 
Ohm,  28. 
Oil,  cod-liver,  319. 

of  bitter  almonds,  artificial,  417. 

of  vitriol,  97. 
Oils,  318. 

animal,  318. 

drying,  318,  375. 

essential,  431. 

fixed,  318. 


Oils,  greasy,  318. 

non-drying,  318,  375. 

semi-drying,  318. 

volatile,  318,  431. 
Oleates,  374. 
Oleflant  gas,  368,  369. 
Olefin  actylene  series,  229. 

alcohols,  371. 

aldehydes,  372. 

dicyanids,  330. 

ketones,  373. 

oxybenzenes,  395. 

series,  229,  368. 

terpenes,  371,  431. 
Olefins,  368,  431. 
Oleomargarine,  622. 
Oleoresins,  438. 
Ollguria,  567. 
Opal,  144. 
Opalisin,  625. 

Open-chain  compounds,  227,  229. 
Opianyl,  407. 

Opium  alkaloids,  472,  484,  488. 
Optical  activity,  25,  265. 
Orcein,  394. 
Orientation,  381. 

in  condensed  compounds,  441. 

in  heterocyclic  compounds,  454. 
Organic  analysis,  205,  219. 

chemistry,  216. 

substances,  217. 

Organo-metallic  compounds,  325. 
Ornithin,  365. 
Orpiment,  127,  129. 
Orsin,  394. 
Orsinol,  394. 
Ortho  acids,  120. 

compounds,  382,  442. 

chlorophenol,  392. 

cresol,  391. 

dibromobenzene,  383. 

dioxybenzene,  393. 

nitro-parabromo-phenol,  383. 
Orthoxycarbanil,  421. 
Osazon'es,  264,  265,  270,  429,  430. 
Osmium,  29,  37,  57,  145,  166. 
Osmosis,  20. 

Osmotic  pressure,  20,  222. 
Ossein,  508. 
Otoliths,  191. 
Ovialbumin,  497. 
Oviglobulins,  497. 
Ovimucoid,  504. 
Ovivitellin,  504. 
Oxacids,  42. 
Oxalate  plasma,  539. 
Oxalylurea,  357. 
Oxamid,  348. 
Oxethylamin,  330,  360. 
Oxethyl-dimethyl-amin,  489. 
Oxhydryl,  43. 
Oxidation,  65. 
Oxids,  65. 

basic,  66. 

indifferent,  66. 

neutral,  66. 

saline,  66. 

Oxim  group,  335,  360. 
Oximidoacetone,  341. 
Oxims,  411,  444. 
Oxindole,  424,  465,  466. 
Oxyacids,  42,  257,  289,  341. 


INDEX 


Oxyacids,  dicarboxylic,  297. 

esters  of,  320. 

monocarboxylic,  289,  290,  293,  362. 

primary,  285. 

Oxyaldehyde  ketones,  262. 
Oxy  aldehydes,  257,  263,  285,  290. 

alkyl  bases,  329,  360. 

amids,  362. 

amins,  329,  330,  332,  360,  493. 

anthracene,  444. 

benzaldehyde,  399. 

butyraldehyde,  372. 

cholin,  332. 

cinchonin,  480. 

cyanids,  257,  290,  341. 

dimorphin,  485. 

diphenols,  447. 
Oxygen,  27,  29,  36,  59,  63,  562,  563. 

allotropic,  66. 
Oxygenated  water,  77. 
Oxy  haemoglobin,  454,  546. 

hexahydrocymene,  435. 

hydroquinone,  395. 

indole,  465. 

methylanthraquinone,  445. 

methylbenzoic  lac  tone,  449. 

morphin,  485. 

naphthalenes,  442. 

naphthylamin,  446. 

neurin,  332. 

phenyl  ethylamin,  422,  425. 

piperidin,  363. 

purin,  356,  359. 

quinolin,  468. 

salts,  44,  52. 
Ozocerite,  232,  323,  438. 
Ozone,  66. 

Painters'  colic,  160. 
Palladium,  29,  37,  57,  61,  166. 
Pancreatic  diastase,  533,  534. 

secretion,  533. 
Papain,  513. 
Papaveraldin,  488. 
Papaverin,  484,  487,  488. 
Para  acetoanisidin,  423. 

acetophenetidin,  423. 

amidoazobenzene,  428. 

amidophenol,  421. 

amidophenyl  alanin,  424,  425. 
Paramylum,  275. 
Para  nitrophenyl  alanin,  425. 

azoamidobenzene,  427. 

chlorophenol,  392. 

compounds,  382,  442. 

conim,  473. 

cresol,  391,  536. 

diamidodiphenyl,  429. 

diazin,  462. 

dibromobenzene,  383. 

dioxybenzene,  394. 
Paraffin,  232. 

dichlorids,  257. 

series,  229. 
Paraffins,  229,  316. 

haloid  derivatives,  233,  315. 

iso,  241. 

meso,  241. 

nitrogen  derivatives,  325. 

normal,  241. 

oxidation-products,  237. 

oxids,  237. 


Paraffins,  sulfur  derivatives,  321. 

formaldehyde,  257. 

globulin,  497,  541. 
Paraldehyde,  258. 
Para  leucanilin,  450. 

methoxylepidin,  481. 

morphin,  487. 

nucleins,  504,  507. 

oxyphenyl  alanin,  424. 

phenetidin,  423. 

phenylene  diamin,  429. 

rosanilin,  448. 

xanthin,  356,  358. 

xylene,  387. 

Parchment,  vegetable,  271. 
Paris  green,  129,  206. 

yellow,  159. 
Pasteuring,  246. 
Parvolins,  460. 
Pear  oil,  315. 
Pearlash,  178. 
Pearl-white,  163. 
Pelletierin,  472,  478. 
Penta  bromanilin,  421. 

carbocyclic  rings,  438,  439. 

methylene  diamin,  333,  334. 

hydrochlorid,  461. 
Pentanes,  285. 
Pentene,  369. 
Pentites,  254. 
Pentane,  460. 
Pentole,  452. 
Pentosans,  265. 

Pentoses,  264,  273,  409,  454,  614. 
Pentosids,  410,  412,  413. 
Peonin,  390. 

Pepsin,  270,  515,  516,  543. 
Pepsinogen,  516,  517. 
Peptone,  ampho,  519. 

anti,  519. 

hemi,  519. 

plasma,  539. 

Peptones,  498,  500,  517,  518,  601. 
Peptonuria,  601. 
Perchlorindone,  441. 
Peri  compounds,  442. 
Periodic  law,  202. 
Perissads,  39. 
Permanent  white,  192. 
Permanganates,  149,  150. 
Petroleum,  231,  232. 

ether,  232. 
Phallin,  495. 
Phellandrene,  432,  433. 
^henacetin,  423. 
Phenanthrene,  438,  441,  444,  446,  462,  484. 

haloids,  442. 

nitrogen  derivatives,  445. 

quinolin,  485. 
Phenanthridin,  462,  463. 
Phenanthrolins,  469. 
Phenanthroquinone,  441. 
Phenates,  390. 
Phenetidins,  418,  423. 
Phenetols,  nitro,  418. 
Phenicin,  390. 
Phenol,  389,  427,  437,  536. 

aldehydes,  403. 

cymylic,  392. 

dyes,  395. 

glucosid,  320. 

paramido,  419,  421. 


670 


INDEX 


Phenol  phthalein,  390. 

Phenols,  385,  388,  403,  415,  436,  448. 

benzylic,  391. 

cresylic,  391. 

diatomic,  393. 

dihydric,  393. 

monoatomic,  389. 

monohydric,  389. 

nitroso,  418. 

of  condensed  hydrocarbons,  442. 

substituted,  392. 

triatomic,  394. 

trihydric,  394. 

unsaturated,  395. 
Phenones,  400. 
Phenyl  acetaldehyde,  424. 

acetamid,  421. 

acetylene,  387,  403. 

acrolein,  399. 

alanin,  424. 

alky]  hydrazins,  429. 

amido  acids,  423. 

amin,  419. 

amins,  422. 

benzenes,  446. 

butylene,  440. 

carbylamins,  422. 

dimethyl  carbinol,  398. 

dimethyl  pyrazolon,  457. 

esters,  389,  391. 

ethene,  387. 

ethers,  390,  391. 

glucosid,  410. 

glycocoll,  424,  425,  464,  466. 

guanidin,  426. 

hydrazids,  294. 

hydrazin,  256,   264,   269,   270,  337,  360, 

411,  429,  436,  457. 
acid  derivatives  of,  430. 
hydrochlorid,  429. 
sodium,  429. 

hydrazones,  256,  429,  465. 

hydroxid,  389. 

hydroxylamin,  419. 

isocyanid,  341,  422. 

methane,  447. 

methyl  carbinol,  398. 

methyl  ketone,  400. 

methyl  pyrazolons,  457. 

pyrazolin,  457. 

pyridins,  461,  469. 

pyridyl,  453. 
compounds,  469. 

salicylate,  404. 

sultid,  415. 

urea,  426. 

urethan,  347,  426. 
Phenylene  diamins,  422. 
Phlebin,  546. 
Phloretin,  394,  413. 
Phloridzin,  413,  559. 
Phloroglucin,  265,  394,  413,  434. 
Phloroglucite,  434. 
Phlorose,  413. 
Phorone,  373. 

Phosgene,  259,  302,  311,  349,  351,  353. 
Phosphamin,  118. 
Phosphates,  112,  120. 
Phosphin,  118. 
Phosphins,  368. 
Phosphoglycoproteids,  500. 
Phosphonia,  118. 


Phosphonium  iodid,  118. 
Phosphorus,  29,  37,  57,  101,  112. 

acids,  110. 

bromids,  118. 

fluorids,  118. 

iodids,  118. 

oxids,  119. 

oxychlorid,  118. 

pentachlorid,  118. 

pentoxid,  119. 

trichlorid,  118,  120. 

triiodid,  89. 

trioxid,  119. 
Phthalazin,  462. 
Phthalein,  phenol,  396. 

pyrogallol,  395. 

resorcinol,  396. 

Phthalems,  389,  396,  402,  414,  449. 
Phthalid,  407,  449. 

lactones,  449. 
Phycite,  254. 

Physiological  chemistry,  510. 
Physostigmin,  493. 
Picene,  438,  439,  441. 
Picnometer,  6.  - 
Picolins,  460,  473. 
Picramid,  421. 
Picrol,  416. 
Pilocarpene,  478. 
Pilocarpidin,  478. 
Pilocarpin,  461,  470,  472,  478, 
Pinene,  432,  433,  435. 

dibromid,  433. 

hydrochJorid,  433. 
Piperazin,  330,  334,  462. 

urate,  368. 
Piperideins,  461. 

Piperidin,  326,  333,  334,  363,  453,  458,  460, 
461,  475. 

hydrochlorid,  326. 

piperate,  475. 
Piperidins,  459,  461. 
Piperidyl  pyrrole,  453. 
compounds,  469. 

pyrroles,  469. 

Piperin,  403,  461,  472,  474. 
Pitch,  385. 
Plasma,  blood,  538,  540. 

coloring  matter  of,  544. 

oxalate,  539. 

peptone,  539. 

salt,  539. 

Plaster  of  Paris,  190. 
Platinic  chlorid,  167. 
Platinocyanids,  345. 
Platinum,  29,  37,  57,  160,  167. 

black,  167. 

sponge,  167. 
Plumbago,  141. 
Plumbates,  158. 
Plumbites,  158. 
Plumboso-plumbic  oxid,  158. 
Po-onin,  395. 
Poisons,  85. 

endogenous,  496. 

exogenous,  496. 

mineral,  135. 
Polarimetry,  24. 
Poles,  27. 
Polymerism,  219. 
Polymethylenes,  379. 
Polysaccharids,  263,  273. 


INDEX 


671 


Polyuria,  567. 
Pompholix,  196. 
Ponceau  dyes,  443. 
Populiu,  414. 
Porcelain,  201. 
Porter,  246. 
Positive  plate,  27. 

pole,  27. 

Potable  waters,  70. 
Potash,  168,  175,  178. 
Potassa,  175. 
Potassium,  29,  37,  58,  168,  175. 

acetate,  178. 

aluminate,  200. 

antiraonyl  tartrate,  180. 

arsenate,  128. 

bichromate,  177. 

bromate,  176. 

bromid,  176. 

carbonates,  178. 

chlorate,  63,  82,  177. 

chlorid,  176. 

cyanate,  181. 

cyanid,  181,  357. 

dichromate,  81,  177. 

disulfld,  176. 

ethylsulfate,  340. 

ferricyanid,  182,  345. 

ferrocyanid,  181,  337. 

fluosilicate,  143. 

formate,  302. 

hydroxid,  175. 

hypochlorite,  177. 

iodate,  176. 

iodhydrargyrate,  212. 

iodid,  176. 

metantimonate,  138. 

myronate,  377,  413. 

nitrate,  176. 

nitrite,  176. 

oxalate,  179. 

oxids,  175. 

pentasulfid,  175. 

perch lorate,  177. 

permanganate,  178. 

phenate,  389,  390,  410. 

plumbate,  157. 

pyroantimonate,  138. 

pyrogallate,  395. 

pyrosulfate,  177. 

quadroxalate,  179. 

silicates,  175. 

sulfates,  177. 

sulfhydrate,  176. 

sulflds,  176. 

sulfltes,  177. 

tartrates,  179,  246,  296. 

thiocyanate,  324,  513. 

titanate,  164. 

trisulfid,  176. 

urate,  355. 

zincate,  193. 
Potatoe  spirit,  249. 
Potential  difference,  27. 
Praseodym,  27,  58. 
Pressure,  critical,  19. 
Preston  salts,  187. 
Proof  spirit,  245. 
Propadiene,  229. 
Propaldehyde,  261. 
Propane,  238. 
Propanols,  240. 


Propantriol,  252. 
Propargyl  alcohol,  371,  372. 

chlorid,  371. 

iodid,  371. 
Propenyl  phenol,  395. 

anisol,  395. 
Propepsin,  517. 
Propeptones,  518. 
Propidene  phenylhydrazone,  465. 
Propine,  229. 
Propiouyl  chlorid,  251. 
Propyl  alcohols,  248. 

amin,  328,  329. 

benzene,  386. 

hydroxid,  248. 

piperidin,  461,  473. 

pseudonitrol,  325. 

pyridins,  460. 
Propylene,  371. 

haloids,  371. 
Pros  compounds,  442. 
Protamin-peptone,  500. 
Protagons,  319,  331,  553. 
Protamins,  500. 
Proteids,  505. 
Protein  granules,  509. 
Proteinochrom,  534. 
Proteinochromogen,  534. 
Proteins,  497,  536. 

vegetable,  509. 
Proteolytic  enzymes,  500. 
Proteoses,  518. 
Prothrombin,  543,  552,  554. 
Protoelastose,  508. 
Protogelatoses,  519. 
Prussian  blue,  156,  182. 
Pseudo  aconitin,  491. 

haemoglobin,  548. 

hyoscyamin,  478. 

leucanilin,  450. 

morphin,  485. 

nitrols,  325. 

nucleins,  497,  504,  507,  519. 

urea,  335. 

Ptomains,  330,  333,  460,  493,  494,  501. 
Ptyalin,  270,  513,  514. 
Puddling,  150. 
Pulegone,  436. 
Purin,  359. 

bases,  356. 

Purple  of  Cassius,  146. 
Purpurin,  445. 

dyes,  445. 
Putrefaction,  300,   331,   333,   334,  335,  365, 

464,  494,  500. 
Putrescin,  333. 
Pyoktanin  blue,  451.  ' 

yellow,  451. 
Pyrazin,  458,  462. 
Pyrazole,  456,  457. 
Pyrazolin,  457. 
Pyrozolons,  457. 
Pyridiazin,  462. 

Pyridin,  378,  452,  453,  454,  458,  460,  461, 
470. 

alkaloids,  472. 

bases,  459,  466,  467,  480. 

homologues,  460. 

methylpyrrole,  474. 

methylpyrrolidin,  474. 

piperidyl,  453. 
Pyrimidin,  462. 


672 


INDEX 


Pyrites,  91,  150,  152. 

copper,  204,  206. 
Pyrocatechin,  393. 
Pyrocatechol,  392,  393. 
Pyrocomane,  458. 
Pyrodin,  431. 
Pyrogallol,  395,  406,  412. 
Pyrollidone,  456. 
Pyrolusite,  148,  149. 
Pyrometer,  14. 
Pyrone,  458. 
Pyroxam,  275. 
Pyroxylic  spirit,  241. 
Pyroxylin,  277. 
Pyrro-a-monozole,  456. 
Pyrrole,  452,  453,  454,  455,  456,  459,  474. 

alkaloids,  472. 

red,  455. 

Pyrrolidin,  456,  470. 
Pyrrolin,  455. 
Pyrrotriazoles,  456. 

Quarternary  ammoniums,  326. 
'     haloids,  328. 

hydroxids,  326,  328. 
Juarternary  compounds,  232 
juartz,  144. 
Juercetin,  413,  464. 
Juercite,  434. 
{uercitrin,  394,  413. 
juicklime,  188. 
jjuina  red,  407. 
Juinicin,  480. 
Juinidin,  470,  478,  480. 
Juinin,  461,  470,  472,  478,  481. 
bisulfate,  479. 
hydriodid,  326. 
hydrosulfate,  479. 
sulfate,  479. 
Quinite,  434. 

Quinol,  392,  394,  434,  590. 
Quinolin,  420,  424,  452,  453,  462,  463,  467, 

468,  480. 

alkaloids,  472,  478. 
bases,  467. 
homologues  of,  468. 
Quinone,  394,  395,  397. 

dioxim,  397. 

Quinones,  396,  418,  444. 
monobenzenic,  396. 
of  condensed  hydrocarbons,  442 
Quinoquinolin,  453. 
Quinovin,  413. 
Quinovose,  413. 
Quinoxim,  419. 

Radicals,  52,  53,  217,  227. 

acid,  278. 

oxidized,  278. 
Raffinose,  273. 
Rational  formulae,  53. 
Reaction,  41. 

Reaction    (Reagent:    See    also    Analytical 
characters;  Tests) 

Adamkiewicz',  455,  502. 

Anderson's,  459. 

biuret,  349,  502. 

Blum's,l600. 

Brouardel  and  Boutmy's,  493. 

De  Vry's,  472. 

diazo,  606. 

dimethyl  amido-azobenzene,  522. 


Reaction,  Ehrlich's,  606. 

Esbach's,  600. 

ferrocyanid,  599. 

Frohde's,  485. 

furfurol,  527. 

Gallois',  434. 

Gmelin's,  528. 

Gunzburg's,  522. 

Hammarsten's,  528. 

Hofmann's,  425. 

Hofmeister's,  365. 

Huppert's,  528. 

Husemann's,  486. 

indophenin,  455. 

indophenol,  421. 

Jaffa's,  591. 

Kossel's,  357. 

Liebermann's,  455,  502. 

Mayer's,  472. 

Millon's,  502. 

murexid,~354,  355. 

Obermayer's,  591. 

Oliver's,  600. 

Nessler's,  105. 

Panum's,  599. 

Pellagri's,  485. 

Petri's,  502. 

Pettenkofer's,  455,  527. 

phenylhydrazin,  429. 

phloroglucin-vanillin,  521. 

pine-shaving,   390,   411,  454,   455,   464, 
465,  467. 

Piria's,  425. 

Reichl's,  502. 

resorcin-sugar,  521. 

Riegler's,  600. 

Roberts',  599. 

Roch's,  600. 

Rosenbach's,  591. 

Scherer's,  365,  425,  434. 

Schiff' s,  349,  451,  454. 

Spiegler's,  600. 

Sonnenschein's,  472. 

Stokes',  546. 

Tanret's,  600. 

Tollens',  615. 

trichloracetic,  599. 

Ufflemann's,  523. 

Weidel's,  356,  357,  358. 

xanthin,  356,  357,  358. 

xanthoproteic,  502. 
Realgar,  127. 
Red  lead,  66. 
Reduction,  62,  150. 
Refraction,  21. 

double,  24. 
Refractometer,  21. 
Reinsch  test,  164. 
Rennet,  515,  623. 
Residues,  53. 
Resins,  431,  437,  438. 

fossil,  438. 
Resistance,  27. 
Resorcin,  394. 
Resorcinol,  392,  394,  402. 

dinitroso,  419. 

phthalem,  396. 
Respiration,  66,  560-566. 
Respiratory  quotient,  561. 
Reticulin,  508. 
Rhamnose,  265,  412,  413. 
Rhigolene,  232. 


INDEX 


673 


Rhodinol,  372. 
Rhodium,  29,  37,  57,  166. 
Ribose,  265. 
Ricin,  495. 
Rings,  227,  378. 
Roburite,  417. 
Rochelle  salt,  180. 
Rock  candy,  271. 

crystal,  144. 

salt,  170. 

Rosanilins,  420,  422,  448,  450. 
Rosin,  433,  438. 
Rosorufln,  459. 

Rubidium,  29,  37,  58,  118,  183. 
Ruby,  199. 
Rufol,  444. 
Ruthenium,  29,  37,  57,  166. 

Sabadillin,  492. 
Saccharates,  265,  269,  272. 
Saccharin,  416. 
Saccharobioses,  263,  270. 
Saccharose,  270,  559. 
Saccharotrioses,  263. 
Safety  oil,  232. 
Saffrol,  395. 
Saffron  surrogate,  418. 
Saffranins,  459. 
Sal  ammoniac,  186. 

soda,  173. 

volatile,  187. 
Salacetol,  404. 
Saheratus,  179. 
Salicin,  398,  399,  404,  413. 
Salicyl  hydrid,  399. 
Salicylal,  399. 
Saligenin,  398,  414. 
Saline  oxids,  66. 
Salipyrin,  458. 
Saliva,  512-515. 

amylolytic  action  of,  514. 

enzymes  of,  513,  514. 

glucase  in,  514. 

parotid,  513. 

ptyalin  in,  514. 

quantity  of,  514. 

sublingual,  513. 

submaxillary,  512. 
Salivary  calculi,  515. 
Salmin,  500. 
Salol,  389,  404,  525. 
Salt,  170. 

of  lemon,  179. 

of  Saturn,  159. 

of  sorrel,  179. 

plasma,  539. 
Saltpeter,  176. 

Chili,  171. 
Salts,  43,  46. 

acid,  43,  45. 

basic,  43, 52. 

bi,  43,  52. 

double,  52. 

haloid,  43. 

neutral,  52. 

oxy,  44,  52. 

sub,  52. 

Samarium,  29,  37,  58. 
Sandarach,  127. 
Sanguinarin,  458. 
Saponiflcation,  312,  318. 
Sapphire,  199. 

43 


Saprin,  333. 

Sarcosin,  336,  348,  351,  364,  578. 

Sarkin,  356. 

Saturated  compounds,  224,  229. 

hydrocarbons,  229. 
Scammonin,  413. 
Scandium,  29,  37,  58,  198,  202. 
Scheele's  green,  206. 
Schweinfurth  green,  206. 
Secalin,  329. 
Seidlitz  salt,  194. 
Selenite,  188,  190. 
Selenium,  29,  37,  57,  91,  100. 
Sericin,  508. 
Serines,  542. 
Serum  albumin,  497,  542,  596. 

blood,  539,  540,  542. 

globulin,  541,  596. 
Sicherheit,  417. 
Silex,  144. 
Silicates,  144. 
Silicibromoform,  144. 
Silicichloroform,  144. 
Silicium,  143. 
Silicon,  29,  37,  57,  141,  143. 

carbid,  144. 

chlorid,  143,  144. 

oxid,  144. 
Silver,  29,  37,  58,  168,  183. 

acetylid,  370. 

benzoate,  414. 

bromid,  184. 

chlorid,  184. 

cyanid,  184. 

fulminate,  343. 

hyponitrite,  109. 

iodid,  184. 

monoxid,  184. 

nitrate,  184. 

oxids,  183. 

Simple  substances,  31. 
Sincalin,  330. 

Six-membered  heterocyclic  compounds,  458. 
Skatole,  465,  494,  499,  536. 
Slag,  150. 

Soaps,  318,  374,  542 
Soapstone,  193. 
Soda,  170,  174. 

baking,  174. 

lye,  170. 

washing,  173. 

water,  304. 
Sodium,  29,  37,  58,  168,  169. 

acetanilid,  422. 

acetate,  173. 

acetylid,  370. 

alcoholate,  244. 

aluminate,  200. 

arsenates,  172. 

arsenites,  128,  172. 

bicarbonate,  174. 

bisulfate,  171. 

borate,  169,  172. 

carbonates,  169,  173. 

chlorate,  173. 

chlorid,  169,  170. 

dioxid,  169. 

ethylate,  244,  314. 

ethylthiosulfate,  193. 

hydroxid,  170. 

hypobromite,  88. 

hypochlorite,  173. 


674 


INDEX 


Sodium,  hyponitrite,  109. 

hyposulflte,  171. 

manganate,  173. 

metaphosphate,  172. 

metarsenite,  172. 

methyl,  279. 

monoxid,  169. 

nitrate,  169,  171. 

nitroprussid,  345. 

oxids,  169. 

permanganate,  173. 

peroxid,  64,  77,  169. 

phenates,  403,  404. 

phenylhydrazin,  429. 

phenyl  sulfld,  389. 

phosphates,  172. 

potassium  tartrate,  180. 

pyroarsenite,  172.. 

pyroborate,  140. 

pyrophosphate,  172. 

pyrosulfate,  171. 

sesquicarbonate,  174. 

silicates,  172. 

sulfate,  169,  171. 

sulfite,  171. 

sulfovinate,  313. 

thiosulfate,  171. 

tungstate,  145. 

urates,  355. 
Solanidin,  414. 
Solanin,  414. 
Solid  green,  419. 
Solubility,  16. 
Soluble  blue,  451. 
Solution,  15. 

supersaturated,  16. 
Somnal,  347. 
Sorbinose,  265,  269. 
Sorbite,  255. 
Sorbitol,  255. 
Sozoiodol,  416. 
Space  isomerids,  375. 
Spartem,  470,  472,  478. 
Specific  gravity,  3. 

of  gases,  221. 
Specific  rotary  power,  25. 
Spectrophotometry,  556. 
Spectroscopy,  21. 
Spectrum,  21. 
Spermaceti,  251,  284,  315. 
Spermin,  334. 
Sperm  oil,  319. 
Spirits,  244,  245,  249. 

of  Mindererus,  187. 

of  wine,  242. 
Spongin,  508. 
Spring  water,  70,  71. 
Stannates,  165. 
Stannic  chlorid,  166. 

oxid,  165. 
Stannous  chlorid,  165. 

hydroxid,  165. 

oxid,  165. 
Starch,  273,  274,  276,  279,  535. 

animal,  275. 

cellulose,  275. 

hydrated,  274. 

paste,  274. 

soluble,  275. 
Steapsin,  533,  534. 
Stearoptones,  433. 
Steel,  150. 


Stercobilin,  528,  537. 
Stercorin,  532,  537. 
Stereochemistry,  266. 
Stereoisomerism,  266,  295. 
Stethol,  315. 
Stibamin,  136. 
Stibins,  368. 
Stibonia,  136. 
Stilbene,  447. 

bromid,  448,  449. 
Stoichiometry,  47. 
Stomach,  test  for  motor  function  of,  525. 

for  resorptlve  activity  of,  525. 
Strontium,  29,  37,  58,  188,  181. 

iodid,  191. 

lactate,  191. 

nitrate,  191. 
Strychnidin,  482. 
Strychnin,  472,  481. 
Strychnos  alkaloids,  472,  481. 
Sturin,  500. 
Styracol,  393. 
Styrolene,  387. 
Sublimation,  18. 
Sub  salts,  52. 
Substitution,  224. 
Succiniraid,  347. 
Succinonitril,  342. 
Succinyl  morphin,  484. 
Sucrates,  272. 
Sugar,  279. 

barley,  271. 

beet,  271. 

burnt,  271. 

candy,  271. 

cane,  270. 

gelatin,  363. 

invert,  269,  272. 

inversion  of,  269,  272,  514. 

maple,  271. 

milk,  272,  297. 

muscovado,  271. 

of  lead,  159. 

raw,  271. 
Sulfates,  99. 
Sulfethylates,  313. 
Sulfhydrates,  93. 
Sulfids,  94. 

Sulfimid,  orthotoluene,  416. 
Sulfites,  95,  97. 
Sulfocarbolates,  416. 
Sulfo  compounds,  92. 
Sulfonal,  313,  321,  323,  551. 
Sulfonation,  415. 
Sulfones,  321,  322. 

aromatic,  415. 
Sulfur,  29,  37,  57,  91 

bromid,  95. 

chlorid,  95. 

dioxid,  93,  95. 

group,  91. 

iodid,  95. 

liver  of,  176. 

oxacids,  96. 

oxychlorids,  95. 

trioxid,  96. 

Sulfurous  chlorid,  95. 
Sulfure'ids,  420. 
Sulfuryl  chlorid,  96. 
Sultones,  443. 
Superphosphate,  190. 
Supersaturation,  16. 


INDEX 


675 


Surface  waters,  70. 
Sulfovinates,  313. 
Sulfoxids,  32'1,  322. 
Sylvestrene,  432. 
Symbols,  40. 

Symmetrical  positions,  382. 
Synthesis,  31,  69,  216. 
Syntonin,  504,  518. 
Syrup,  271. 

Talc,  193. 
Talose,  265. 
Tanacetone,  436. 
Tannins,  406. 
Tantalium,  29,  37,  57,  145. 
Tartar,  cream  of,  179,  296. 

crude,  179. 

emetic,  180. 

salt  of,  178. 

soluble,  179. 

Tartronyl  urea,  352,  353. 
Taurin,  322,  366,  377,  526,  527,  530. 
Teichmann's  crystals,  458. 
Tellurium,  29,  37,  57,  91,  100. 
Temperature,  13. 

absolute,  14 

critical,  19. 

Ternary  compounds,  32. 
Terpans,  432. 

Terpene  nitrosochlorids,  431. 
Terpenes,  431. 

olefln,  371. 
Terpenogens,  371. 
Terpin,  432. 

hydrate.  432,  435. 
Terpins,  435. 
Terpinene,  432. 
Terpineols,  432,  435. 
Terpinolene,  432. 
Terra  alba,  190. 
Tertiary  butyl  alcohol,  240. 
Test     (See     also    Analytical    characters; 
Reaction).  1 

Almen's,  610. 

biuret,  581. 

Boettger's,  610. 

Ewald's,  525. 

Fehling's,  610,  612. 

fermentation,  611. 

Fresenius  and  Von  Babo's,  135. 

Gerhardt's,  616.  . 

guaiac,  604. 

Gunning's,  616. 

hffimin,  550. 

Hammarsten's,  605. 

Heller's,  589,  604. 

Hoffmann's  328. 

Knapp's,  614. 

Legal's,  616. 

Lieben's,  616. 

Marsh's,  133,  139. 

Moore's,  609. 

Nylander's,  610. 

Panum's,  602. 

Penzold's,  617. 
-  Pettenkofer's,  502,  605. 

phenylhydrazin,  611. 

polarization,  611,  612. 

Reinsch's,  131.  139. 

Reynold's,  616. 

Rosenbach's,  605. 

Smith's,  606. 


Test,  Teichinanu's,  604. 

Trommer's,  204,  609. 
Tetanin,  495. 

Tetra  acetyl  erythrol,  319. 
bromanilin,  421. 
acetic  glucose,  320. 
chloro  benzenes,  388, 
chloronaphthalene,  402. 
cosane,  229. 

ethylium  hydroxid,  329. 
heteroatomic  compounds,  453. 
hydro  benzenes,  379,  431. 
diphenyl,  446. 
methylpyridin,  475,  476. 
naphthols,  443. 
naphthylamin,  446. 
pyrazole,  457. 
pyridins,  461. 
pyrrole,  455. 
quinolins,  468. 
strychnin,  482. 
ketones,  262. 

methyl  ammonium  hydroxid,  327,  329. 
benzenes,  386. 
diamidobenzhydrol,  448. 
diamidophenyl  methane,  448. 
diamidodiphenyl  methane,  448. 
diamidotriphenyl  methane,  450. 
methylene  diamin,  323,  330. 
hydrochlorid,  450. 
imin,  456. 

Tetrammonium  iodids,  327. 
Tetra  morphin,  485. 
nitroerythrol,  319. 
phenylsilicon,  447. 
Tetrazins,  452,  453,  461,  462. 
Tetrazoles,  452,  456. 
Tetrethylammonium  chlorid,  327 
Tetriodopyrrole,  455. 
Tetronal,  323. 
Tetroses,  264. 
Thallin,  468. 

Thallium,  29,  37,  58,  188. 
Thebain,  484,  487,  488,  490. 
Thebaol,  490. 
Thein,  358,  472. 

Theobromin,  354,  356,  358,  470,  472. 
Theophyllin,  356,  358. 
Thermal  unit,  19. 
Thermometers,  13. 
Thermometric  scales,  14. 
Thetin,  453. 
Thialdin,  258. 
Thio  acetals,  323. 
acids,  321,  323. 
alcohol,  ethylic,  321. 
alcohols,  321. 
aldehydes,  260,  321,  322. 
anhydrids,  94,  323. 
antimonates,  139. 
antimonites,  138. 
aromatic  compounds,  415. 
arsenites,  127. 
bases,  43. 
Thiocol,  373. 
Thio  compounds,  92. 
diazoles,  456. 
ethers,  321. 
ctliylates,  321. 
formaldehyde,  344. 
glycols,  321,  322. 
ketones,  321,  323. 


676 


INDEX 


Thionyl  chlorid,  313. 

Thiophene,  385,  452,  453,  454,  455,  456. 

Thiophenol,  415. 

Thiourea,  350. 

Thorium,  29,  37,  58. 

Thrombin,  540,  541,  554. 

Thujone,  436. 

Thymene,  392. 

Thymol,  391,  392. 

Tin,  29,  37,  57,  164,  165. 

chlorids,  165. 

crystals,  165. 

foil,  165. 

hydrates,  165. 

oxids,  165. 

oxychlorid,  166. 

plate,  165. 

stone,  165. 
Tincal,  172. 
Tinctures,  244. 
Titanium,  29,  37;  57,  164. 
Tolane,  447,  448. 
Toluene,  279,  385,  386,  388,  447. 

sulfonic  chlorids,  415. 
Toluidins,  418,  420. 
Toluol,  386. 
Toluyl  benzene,  446. 

dimethyl  pyrazolon,  458. 
Toluylene,  447. 

glycol,  449. 

red,  459. 
Tolypyrin,  458. 
Topaz,  198,  199. 
Tophi.  354. 
Toxalbumens,  495. 

Toxicology  (see  also:   Action  on  the  econ- 
omy). 

aconite,  492. 

arsenic,  128. 

atropin,  476. 

hydrochloric  acid,  85. 

hydrogen  sulfid,  93. 

iodin,  89. 

morphin,  490. 

nicotin,  474. 

nitric  acid,  112. 

nitrogen  tetroxid,  108. 

nitrous  fumes,  108. 

opium,  490. 

phosphorus,  114. 

strychnin,  483. 

sulfuric  acid,  99. 
Toxins,  493,  495. 
Transterpin,  435. 
Tri  acetic  glucose,  320. 

acetonamin,  360. 

amido  azobenzene,  110,  422. 
benzenes,  422. 

diphenyl-m-toluyl  methane,  450. 
triphenyl  methanes,  450. 

amids,  345. 

amins,  326,  335. 

azins,  461. 

azoles,  456. 

bromhydrin,  289. 

bromoanthraquinone,  445. 

bromomethane,  236. 

bromophenol,  390,  393. 

butyrin,  317. 

caprin,  317. 

caproin,  317. 

caprylin,  317, 


Tri  chloracetal,  261. 

chloracetyl  hydrate,  258. 

chloraldehyde,  258. 

chloranilins,  421. 

chlormethane,  234. 

chlorobenzenes,  388. 

ethylene  diamin,  330. 

formaldehyde,  322. 

glycerids,  316,  317. 
Trigonellin,  472,  478. 
Tri  heteroatomic  compounds,  453. 

iodomethane,  236. 

iodophenol,  393. 

ketones,  262. 
aromatic,  400. 

margariu,  317. 
Trimethyl  acetic  betain,  332. 

amin,  327,  328,  330,  332. 

ammonium  salts,  329. 

benzenes,  386,  387. 

ethylene,  369. 

glycocoll,  332. 

oxethylammomum  hydroxid,  330. 

oxethylidene  ammonium  hydroxid,  331. 

vinyl  ammonium  hydroxid,  331. 

xanthin,  358. 
Trimethylene  diamin,  330,  333. 

imid,  453. 

oxid,  453. 

trisulfone,  322. 
Trimorphin,  485. 
Trimorphism,  12. 
Tri  nitranilins,  421. 

nitroglycerol,  316. 

nitrophenols,  390,  418. 

olein,  318. 
Trional,  323. 
Trioses,  264. 
Trioxy  anthraquinone.  445. 

coumarin,  412. 

ethylene  amin,  330. 

methyl  anthraquinone,  445. 

purifl,  354,  359. 
Tripalmitin,  317,  318. 
Triphenyl  benzene,  446. 

carbinol,  448. 

methane,  447. 
dyes,  390. 

pararosanilin,  451. 
Triple  phosphate,  194,  575. 
Trisaccharids,  263,  273. 
Tristearin,  317,  318. 
Trithioaldehydes,  260,  322, 
Trithioformaldehyde,  322. 
Tropelns,  477. 
Tropeolins,  443. 
Tropidin,  475,  476. 
Tropin,  461,  475,  476. 

phenyl  hydracrylate,  476. 

tropate,  475,  476. 
Trypsin,  270,  365,  533,  536,  543. 
Tryptophan,  534. 
Tungsten,  29,  37,  57,  145. 
Turnbull's  blue,  156. 
Turner's  yellow,  159. 
Turpentine,  432,  433. 

essence  of,  433. 

oil  of,  433,  435,  437. 
Turpeth  mineral,  214. 
Tutty,  196. 
Types,  53. 
Typhotoxin,  495, 


INDEX 


677 


Typical  elements,  57,  59. 

formulae,  53. 
Tyrosin,  365,  424,  499,  519,  544,  617. 

Ulmin,  502. 

Umbelliferone,  463,  464. 
Unsaturated  compounds,  224,  368,  371. 
Unsymmetrical  positions,  382. 
Uracyl,  353. 
Uralium,  347. 
Uramils,  352. 
Uranates,  156. 
Uranium,  29,  37,  57,  156. 
Uranyl,  156. 
Urates,  355. 
Urazin,  462. 

Urea,  226,  326, 335,  336,  342,  343, 346,  348,351, 
352,  353,  354,  355,  356,  544,  576-585. 

acetyl,  351. 

amidomalonyl,  352. 

diacetyl,  351. 

glycolyl,  351. 

malony],  352. 

mesoxalyl,  352. 

nitrate,  349. 

nitromalonyl,  352. 

oxalate,  349. 

oxalyl,  352,  353,  357. 

tartronyl,  352,  353. 
Ureas,  acidyl,  350. 

alkyl,  350,  351. 

compound,  350. 
Urei'ds,  350. 

diacidyl,  351. 

mixed,  351. 
Urethans,  346. 
Urine,  566-618. 

abnormal  constituents,  570,  596. 

acetone,  615,  616. 

acetylacetic  acid,  615. 

albumin,  596,  601. 

albumoses,  601,  602. 

alkaptonuria,  606. 

alkaline  phosphates,  569,  574. 

allantoin,  589. 

ammonium  carbonate,  569. 

biliary  constituents,  605. 

catechol,  590. 

chlorids,  571. 

chondroitin  sulfuric  acid,  595,  603. 

chromogens,  591. 

color,  568. 

composition,  570. 

consistency,  566. 

creatiriin,  579,  585. 

cystin,  593,  617. 

earthy  phosphates,  574,  576. 

Ehrlich's  diazo  reaction,  606. 

ester  sulfates,  589,  603. 

ether  sulfates,  573. 

fructose,  614. 

globulin,  601. 

glucose,  594,  607-614. 

glucuronic  acid,  594,  611,  615. 

glycosuric  acid,  606. 

hsematoporphyrin,  591,  604. 

haemoglobin,  604. 

hippuric  acid,  588. 

indican,  590. 

indole  compounds,  573. 

indoxyl  compounds,  590. 

indoxyl  glucuronic  acid,  590,  594. 


Urine,  inosite,  615. 

lactose,  614. 

laiose,  614. 

leucin,  614. 

leucomains,  595. 

maltose,  611,  614. 

melanin,  606. 

metallic  elements,  576. 

mineral  constituents,  533. 
sulfates,  573. 

mucin,  602. 

mucoid,  602. 

mucus,  603. 

nitrogen,  576,  578,  579. 

nitrogenous  equilibrium,  579. 

normal  constituents,  571. 

nubecula,  566,  602. 

nucleic  acids,  603. 

nucleoalbumen,  603. 

nucleohiston.  603. 

nucleoproteids,  602. 

odor,  568. 

of  serpents,  354. 

oxalic  acid,  589,  594. 

oxaluric  acid,  589. 

oxy butyric  acid,  611,  615. 

oxyproteic  acid,  595. 

paracresylsulfates,  590. 

peptones,  601,  602. 

pentoses,  614. 

phenolic  compounds,  573. 

phenylglucuronic  acid,  590. 

phenylsulfates,  590. 

phosphates,  567,  569,  570,  574. 

physical  properties,  566. 

pigments,  591. 

proteins,  596. 

ptomai'ns,  595. 

quantity,  567. 

quinol,  590. 

reaction,  568. 

reducing  substances,  593 

serum  albumin,  596. 

serum  globulin,  596. 

silicic  acid,  571. 

skatoxyl  compounds,  590,  591. 

specific  gravity,  567. 

sulfates,  573, 

taurocarbamic  acid,  595. 

taurocholic  acid,  603. 

thiocyanate,  595. 

total  nitrogen,  585. 

toxicity,  595. 

tyrosin,  578,  617. 

urates,  567,  569,  586. 

urea,  576-585. 

uric  acid,  569,  578,  586 

urobilinogen,  591,  592. 

urochrom,  591,  592. 

uroerythrin,  591,  593. 

urohaamatin,  591. 

urorosein,  606. 

uroxanthin,  590. 

xanthin  bases,  588. 
Urobilin,  528,  551,  591,  592. 
Urobilinogen,  591,  593. 
Urobilinoids,  592. 
Urochrom,  591,  592. 
Uroerythrin,  591,  592. 
Urohromatin,  591. 
Urorosein,  606. 
Uroxanthin,  466,  590. 


678 


INDEX 


Valence,  39. 
Valerene,  369. 
Valeraldehyde,  238. 
Valerolactam,  363. 
Vanadium,  29,  37,  57,  144. 

oxids,  144. 
Vanadyl  salts,  144. 
Vanillin,  399,  411. 
Vaporization,  17. 
Vapors,  19. 
Varech,  88. 
Vaseline,  232. 
Vegetable  albumins,  509. 

caseins,  509. 

globulins,  509. 

proteins,  509. 
Venetian  red,  151. 
Ventilation,  306. 
Veratrin,  472,  492. 
Veratrol,  393,  394. 
Verdigris,  207. 
Vermilion,  210. 
Verona  yellow,  159. 
Vicinal  positions,  382. 
Victoria  orange,  418. 
Vinegar,  280. 

distilled,  281. 

radical,  281. 
Vinyl,  371. 

alcohol,  371. 

amin,  330,  331,  377. 

bromid,  370,  371. 

chlorid,  371. 

pyridin,  461. 
Vitelloses,  518. 
Vitriol,  blue,  205. 

green,  153. 

oil  of,  97. 

white,  197. 
Volt,  28. 
Voltage,  27. 

Water,  67. 

action  of  on  lead,  157. 

bitter,  194. 

chlorids  in,  71. 

deep,  70. 

electrolysis  of,  59,  63,  66. 

gas,  232. 

ground,  70. 

hardness  of,  72. 

impurities  in,  71. 

lead  in,  161. 

meteoric,  70. 

mineral,  75. 

of  crystallization,  12,  48,  67,  69. 

of  constitution,  69. 

organic  matter  in,  72. 

oxygenated,  77. 

physiology  of,  76. 

poisonous  metals  in,  73. 

potable,  70. 

purification  of,  74,  75. 

spring,  70,  71. 

surface,  70. 


Water,  total  solids  in,  71. 

vapor  of  in  air,  103. 
Watt,  28. 
Weight,  2. 

absolute,  3. 

apparent,  3. 

atomic,  35,  36. 

equivalent,  40. 

molecular,  38. 

of  gases,  61. 

specific,  3,  4. 
Whey,  621. 
White  lead,  160. 

ore,  157. 

precipitate,  212. 
Wines,  245,  246. 
Witherite,  192. 
Wolfram,  145. 
Wood  alcohol,  241. 

distillation  of,  279. 

naphtha,  241. 

spirit,  241. 

tar,  279. 

vinegar,  241. 
Wort,  242. 

Xanthin,  354,  355,  356,  357,  359,  588. 

bases,  354,  356,  506,  544,  578,  588 
Xanthocreatinin,  336. 
Xanthone,  404. 
Xanthones,  464. 
Xenols,  391. 
Xylene,  385. 

glycols,  398. 
Xylenes,  386,  402. 

amido,  420. 
Xylenols,  391. 
Xylidins,  420. 
Xylodin,  275. 
Xylols,  386. 
Xylose,  265. 

Yeast,  242. 
Yellow  wash,  209. 
Ytterbium,  29,  37,  58. 
Yttrium,  29,  37,  58. 

Zein,  509. 

Zinc,  29,  37,  58,  60,  193,  195. 

blende,  195. 

butter  of,  196. 

carbonates,  197. 

chlorid,  196. 

ethid,  325. 

ethyl,  325. 

hydroxid,  196. 

methid,  325. 

methyl,  400. 

oxid,  196. 

oxycarbonate,  197. 

sulfate,  197. 
Zincates,  193,  196. 
Zirconia,  164. 
Zirconium,  29,  37,  57,  164. 
Zymogens,  514. 


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